Investments in Marketable Debt Securities (Tables)
   | 
3 Months Ended | 
Mar. 31, 2021  | 
| Investments, Debt and Equity Securities [Abstract] | 
 
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| Schedule of Amortized Cost, Allowance for Credit Losses, Gross Unrealized Gains/Losses in Accumulated Other Comprehensive Income/Loss and Fair Value of Marketable Securities, Available-for-Sale, by Type of Security | 
Amortized cost, allowance for credit losses, gross unrealized gains/losses in accumulated other comprehensive income/loss and fair value of marketable debt securities,   by type of security consisted of the following (in thousands):    
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|   | 
   | 
March 31, 2021 | 
  | 
 
|   | 
   | 
Amortized  Cost | 
  | 
   | 
Allowance  for Credit  Losses | 
  | 
   | 
Gross  Unrealized  Gains | 
  | 
   | 
Gross  Unrealized  Losses | 
  | 
  | 
Fair  Value | 
  | 
 
 | 
   | 
  | 
  | 
  | 
   | 
  | 
  | 
  | 
   | 
  | 
  | 
  | 
   | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
 | 
   | 
$ | 
69,217 | 
  | 
   | 
$ | 
—   | 
  | 
   | 
$ | 
23 | 
  | 
   | 
$ | 
—   | 
  | 
  | 
$ | 
69,240 | 
  | 
 
U.S. government sponsored entities  | 
   | 
  | 
11,450 | 
  | 
   | 
  | 
—   | 
  | 
   | 
  | 
4 | 
  | 
   | 
  | 
—   | 
  | 
  | 
  | 
11,454 | 
  | 
 
 | 
   | 
  | 
53,793 | 
  | 
   | 
  | 
—   | 
  | 
   | 
  | 
7 | 
  | 
   | 
  | 
—   | 
  | 
  | 
  | 
53,800 | 
  | 
 
|   | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
  | 
   | 
   | 
  | 
 
|   | 
   | 
$ | 
134,460 | 
  | 
   | 
$ | 
—   | 
  | 
   | 
$ | 
34 | 
  | 
   | 
$ | 
—   | 
  | 
  | 
$ | 
134,494 | 
  | 
 
|   | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
  | 
   | 
   | 
  | 
 
 | 
   | 
  | 
  | 
  | 
   | 
  | 
  | 
  | 
   | 
  | 
  | 
  | 
   | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
 | 
   | 
$ | 
22,342 | 
  | 
   | 
$ | 
—   | 
  | 
   | 
$ | 
179 | 
  | 
   | 
$ | 
—   | 
  | 
  | 
$ | 
22,521 | 
  | 
 
U.S. government sponsored entities  | 
   | 
  | 
1,012 | 
  | 
   | 
  | 
—   | 
  | 
   | 
  | 
36 | 
  | 
   | 
  | 
(3 | 
)  | 
  | 
  | 
1,045 | 
  | 
 
 | 
   | 
  | 
35,424 | 
  | 
   | 
  | 
—   | 
  | 
   | 
  | 
1,505 | 
  | 
   | 
  | 
(60 | 
)  | 
  | 
  | 
36,869 | 
  | 
 
Asset-backed securities (“ABS”) and other  | 
   | 
  | 
6,336 | 
  | 
   | 
  | 
—   | 
  | 
   | 
  | 
166 | 
  | 
   | 
  | 
(6 | 
)  | 
  | 
  | 
6,496 | 
  | 
 
|   | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
  | 
   | 
   | 
  | 
 
|   | 
   | 
$ | 
65,114 | 
  | 
   | 
$ | 
—   | 
  | 
   | 
$ | 
1,886 | 
  | 
   | 
$ | 
(69 | 
)  | 
  | 
$ | 
66,931 | 
  | 
 
|   | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
  | 
   | 
   | 
  | 
 
|   | 
  | 
 
|   | 
   | 
December 31, 2020 | 
  | 
 
|   | 
   | 
Amortized  Cost | 
  | 
   | 
Allowance  for Credit  Losses | 
  | 
   | 
Gross  Unrealized  Gains | 
  | 
   | 
Gross  Unrealized  Losses | 
  | 
  | 
Fair  Value | 
  | 
 
 | 
   | 
  | 
  | 
  | 
   | 
  | 
  | 
  | 
   | 
  | 
  | 
  | 
   | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
 | 
   | 
$ | 
75,887 | 
  | 
   | 
$ | 
—   | 
  | 
   | 
$ | 
88 | 
  | 
   | 
$ | 
(5 | 
)  | 
  | 
$ | 
75,970 | 
  | 
 
U.S. government sponsored entities  | 
   | 
  | 
32,439 | 
  | 
   | 
  | 
—   | 
  | 
   | 
  | 
8 | 
  | 
   | 
  | 
—   | 
  | 
  | 
  | 
32,447 | 
  | 
 
 | 
   | 
  | 
49,822 | 
  | 
   | 
  | 
—   | 
  | 
   | 
  | 
20 | 
  | 
   | 
  | 
(1 | 
)  | 
  | 
  | 
49,841 | 
  | 
 
|   | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
  | 
   | 
   | 
  | 
 
|   | 
   | 
$ | 
158,148 | 
  | 
   | 
$ | 
—   | 
  | 
   | 
$ | 
116 | 
  | 
   | 
$ | 
(6 | 
)  | 
  | 
$ | 
158,258 | 
  | 
 
|   | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
  | 
   | 
   | 
  | 
 
 | 
   | 
  | 
  | 
  | 
   | 
  | 
  | 
  | 
   | 
  | 
  | 
  | 
   | 
  | 
  | 
  | 
  | 
  | 
  | 
  | 
 
 | 
   | 
$ | 
3,375 | 
  | 
   | 
$ | 
—   | 
  | 
   | 
$ | 
266 | 
  | 
   | 
$ | 
—   | 
  | 
  | 
$ | 
3,641 | 
  | 
 
U.S. government sponsored entities  | 
   | 
  | 
1,114 | 
  | 
   | 
  | 
—   | 
  | 
   | 
  | 
38 | 
  | 
   | 
  | 
—   | 
  | 
  | 
  | 
1,152 | 
  | 
 
 | 
   | 
  | 
34,183 | 
  | 
   | 
  | 
—   | 
  | 
   | 
  | 
2,137 | 
  | 
   | 
  | 
(33 | 
)  | 
  | 
  | 
36,287 | 
  | 
 
 | 
   | 
  | 
6,509 | 
  | 
   | 
  | 
—   | 
  | 
   | 
  | 
195 | 
  | 
   | 
  | 
(11 | 
)  | 
  | 
  | 
6,693 | 
  | 
 
|   | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
  | 
   | 
   | 
  | 
 
|   | 
   | 
$ | 
45,181 | 
  | 
   | 
$ | 
—   | 
  | 
   | 
$ | 
2,636 | 
  | 
   | 
$ | 
(44 | 
)  | 
  | 
$ | 
47,773 | 
  | 
 
|   | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
  | 
   | 
   | 
  | 
 
  
 | 
| Available-for-sale Marketable Debt Securities in a Continuous Unrealized Loss Position | 
The Company’s investments in marketable debt securities,   that have been in a continuous unrealized loss position, for which an allowance for credit losses has not been recorded, by type of security consisted of the following (in thousands):    
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 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 
|   | 
   | 
March 31, 2021 | 
  | 
 
|   | 
   | 
Less than 12 months | 
  | 
  | 
12 months or   greater | 
  | 
  | 
Total | 
  | 
 
|   | 
   | 
Fair  Value | 
  | 
   | 
Gross  Unrealized  Losses | 
  | 
  | 
Fair  Value | 
  | 
   | 
Gross  Unrealized  Losses | 
  | 
  | 
Fair  Value | 
  | 
   | 
Gross  Unrealized  Losses | 
  | 
 
U.S. government sponsored entities  | 
   | 
$ | 
139 | 
  | 
   | 
$ | 
(3 | 
)  | 
  | 
$ | 
—   | 
  | 
   | 
$ | 
—   | 
  | 
  | 
$ | 
139 | 
  | 
   | 
$ | 
(3 | 
)  | 
 
 | 
   | 
  | 
20,447 | 
  | 
   | 
  | 
(52 | 
)  | 
  | 
  | 
139 | 
  | 
   | 
  | 
(8 | 
)  | 
  | 
  | 
20,586 | 
  | 
   | 
  | 
(60 | 
)  | 
 
 | 
   | 
  | 
363 | 
  | 
   | 
  | 
—   | 
  | 
  | 
  | 
345 | 
  | 
   | 
  | 
(6 | 
)  | 
  | 
  | 
708 | 
  | 
   | 
  | 
(6 | 
)  | 
 
|   | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
  | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
  | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
 
|   | 
   | 
$ | 
20,949 | 
  | 
   | 
$ | 
(55 | 
)  | 
  | 
$ | 
484 | 
  | 
   | 
$ | 
(14 | 
)  | 
  | 
$ | 
21,433 | 
  | 
   | 
$ | 
(69 | 
)  | 
 
|   | 
   | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
  | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
  | 
   | 
   | 
  | 
   | 
   | 
   | 
  | 
 
  
   
 | 
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 | 
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 | 
 | 
 | 
 | 
 | 
 | 
 |   
|   | 
   | 
December 31, 2020 | 
  |   
|   | 
   | 
Less than 12 months | 
  | 
  | 
12 months or greater | 
  | 
  | 
Total | 
  |   
|   | 
   | 
Fair  Value | 
  | 
   | 
Gross  Unrealized  Losses | 
  | 
  | 
Fair  Value | 
  | 
   | 
Gross  Unrealized  Losses | 
  | 
  | 
Fair  Value | 
  | 
   | 
Gross  Unrealized  Losses | 
  |   
|    | 
   | 
$ | 
41,702 | 
  | 
   | 
$ | 
(5 | 
)  | 
  | 
$ | 
—   | 
  | 
   | 
$ | 
—   | 
  | 
  | 
$ | 
41,702 | 
  | 
   | 
$ | 
(5 | 
)  |   
|    | 
   | 
  | 
29,810 | 
  | 
   | 
  | 
(34 | 
)  | 
  | 
  | 
—   | 
  | 
   | 
  | 
—   | 
  | 
  | 
  | 
29,810 | 
  | 
   | 
  | 
(34 | 
)  |   
|    | 
   | 
  | 
546 | 
  | 
   | 
  | 
(6 | 
)  | 
  | 
  | 
157 | 
  | 
   | 
  | 
(5 | 
)  | 
  | 
  | 
703 | 
  | 
   | 
  | 
(11 | 
)  |   
|   | 
   | 
      | 
      | 
  | 
   | 
      | 
      | 
  | 
  | 
      | 
      | 
  | 
   | 
      | 
      | 
  | 
  | 
      | 
      | 
  | 
   | 
      | 
      | 
  |   
|   | 
   | 
$ | 
72,058 | 
  | 
   | 
$ | 
(45 | 
)  | 
  | 
$ | 
157 | 
  | 
   | 
$ | 
(5 | 
)  | 
  | 
$ | 
72,215 | 
  | 
   | 
$ | 
(50 | 
)  |   
|   | 
   | 
      | 
      | 
  | 
   | 
      | 
      | 
  | 
  | 
      | 
      | 
  | 
   | 
      | 
      | 
  | 
  | 
      | 
      | 
  | 
   | 
      | 
      | 
  |      
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| Gross Realized Gains and Losses from Sale of Available for Sale Marketable Debt Securities | 
Gross realized gains and losses from the sales of the Company’s marketable debt securities,   consisted of the following (in thousands):    
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 |   
|   | 
   | 
Three Months Ended  March 31, | 
  |   
|   | 
   | 
2021 | 
  | 
   | 
2020 | 
  |   
|    | 
   | 
$ | 
1 | 
  | 
   | 
$ | 
53 | 
  |   
|   | 
   | 
      | 
      | 
  | 
   | 
      | 
      | 
  |   
 Gross realized losses  (1) 
   | 
   | 
$ | 
—   | 
  | 
   | 
$ | 
—   | 
  |   
|   | 
   | 
      | 
      | 
  | 
   | 
      | 
      | 
  |       
(1)  | 
 Recorded in other income (expense), net in the condensed consolidated statements of net and comprehensive income. The cost basis of securities sold were determined based on the specific identification method.     |      
 | 
| Schedule of Amortized Cost and Fair Value of Marketable Debt Securities, Available-for-Sale, by Contractual Maturity | 
Amortized cost and fair value of marketable debt securities,   by contractual maturity consisted of the following (in thousands, except weighted average data):    
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 | 
 |   
|   | 
   | 
March 31, 2021 | 
  | 
   | 
December 31, 2020 | 
  |   
|   | 
   | 
Amortized  Cost | 
  | 
   | 
Fair Value | 
  | 
   | 
Amortized  Cost | 
  | 
   | 
Fair Value | 
  |   
|    | 
   | 
$ | 
134,460 | 
  | 
   | 
$ | 
134,494 | 
  | 
   | 
$ | 
158,148 | 
  | 
   | 
$ | 
158,258 | 
  |   
 Due after one year through five years    | 
   | 
  | 
50,401 | 
  | 
   | 
  | 
51,534 | 
  | 
   | 
  | 
30,604 | 
  | 
   | 
  | 
32,041 | 
  |   
 Due after five years through ten years    | 
   | 
  | 
10,323 | 
  | 
   | 
  | 
10,891 | 
  | 
   | 
  | 
10,022 | 
  | 
   | 
  | 
11,044 | 
  |   
|    | 
   | 
  | 
4,390 | 
  | 
   | 
  | 
4,506 | 
  | 
   | 
  | 
4,555 | 
  | 
   | 
  | 
4,688 | 
  |   
|   | 
   | 
      | 
      | 
  | 
   | 
      | 
      | 
  | 
   | 
      | 
      | 
  | 
   | 
      | 
      | 
  |   
|   | 
   | 
$ | 
199,574 | 
  | 
   | 
$ | 
201,425 | 
  | 
   | 
$ | 
203,329 | 
  | 
   | 
$ | 
206,031 | 
  |   
|   | 
   | 
      | 
      | 
  | 
   | 
      | 
      | 
  | 
   | 
      | 
      | 
  | 
   | 
      | 
      | 
  |   
 Weighted average contractual maturity    | 
   | 
  | 
  | 
  | 
   | 
  | 
1.7 years | 
  | 
   | 
  | 
  | 
  | 
   | 
  | 
1.6   years | 
  |      
 |