Quarterly report pursuant to Section 13 or 15(d)

Investments in Marketable Debt Securities, Available for Sale - Amortized Cost and Fair Value of Investments in Available for Sale Securities Unrealized Loss Position (Detail)

v3.21.2
Investments in Marketable Debt Securities, Available for Sale - Amortized Cost and Fair Value of Investments in Available for Sale Securities Unrealized Loss Position (Detail) - USD ($)
$ in Thousands
Sep. 30, 2021
Dec. 31, 2020
Schedule of Available-for-sale Securities [Line Items]    
Available for sale securities continuous unrealized loss position for less than 12 months, fair value $ 58,181 $ 72,058
Available for sale securities continuous unrealized loss position for less than 12 months, gross unrealized loss (65) (45)
Available for sale securities continuous unrealized loss position for 12 months or longer, fair value 221 157
Available for sale securities continuous unrealized loss position for 12 months or longer, gross unrealized loss (1) (5)
Available for sale securities continuous unrealized loss position, fair value 58,402 72,215
Available for sale securities continuous unrealized loss position, gross unrealized loss (66) (50)
U.S. Treasuries [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available for sale securities continuous unrealized loss position for less than 12 months, fair value 44,428 41,702
Available for sale securities continuous unrealized loss position for less than 12 months, gross unrealized loss (26) (5)
Available for sale securities continuous unrealized loss position for 12 months or longer, fair value 0 0
Available for sale securities continuous unrealized loss position for 12 months or longer, gross unrealized loss 0 0
Available for sale securities continuous unrealized loss position, fair value 44,428 41,702
Available for sale securities continuous unrealized loss position, gross unrealized loss (26) (5)
U.S. Government Sponsored Entities [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available for sale securities continuous unrealized loss position for less than 12 months, fair value 123  
Available for sale securities continuous unrealized loss position for less than 12 months, gross unrealized loss (2)  
Available for sale securities continuous unrealized loss position for 12 months or longer, fair value 0  
Available for sale securities continuous unrealized loss position for 12 months or longer, gross unrealized loss 0  
Available for sale securities continuous unrealized loss position, fair value 123  
Available for sale securities continuous unrealized loss position, gross unrealized loss (2)  
Corporate debt [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available for sale securities continuous unrealized loss position for less than 12 months, fair value 12,501 29,810
Available for sale securities continuous unrealized loss position for less than 12 months, gross unrealized loss (33) (34)
Available for sale securities continuous unrealized loss position for 12 months or longer, fair value 0 0
Available for sale securities continuous unrealized loss position for 12 months or longer, gross unrealized loss 0 0
Available for sale securities continuous unrealized loss position, fair value 12,501 29,810
Available for sale securities continuous unrealized loss position, gross unrealized loss (33) (34)
ABS and other [Member]    
Schedule of Available-for-sale Securities [Line Items]    
Available for sale securities continuous unrealized loss position for less than 12 months, fair value 1,129 546
Available for sale securities continuous unrealized loss position for less than 12 months, gross unrealized loss (4) (6)
Available for sale securities continuous unrealized loss position for 12 months or longer, fair value 221 157
Available for sale securities continuous unrealized loss position for 12 months or longer, gross unrealized loss (1) (5)
Available for sale securities continuous unrealized loss position, fair value 1,350 703
Available for sale securities continuous unrealized loss position, gross unrealized loss $ (5) $ (11)