Quarterly report pursuant to Section 13 or 15(d)

Investments in Marketable Securities - Amortized Cost and Fair Value of Investments in Available for Sale Securities (Detail)

v3.19.3
Investments in Marketable Securities - Amortized Cost and Fair Value of Investments in Available for Sale Securities (Detail) - USD ($)
$ in Thousands
Sep. 30, 2019
Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]    
Available for sale securities continuous unrealized loss position for less than 12 months, unrealized loss $ (28) $ (576)
Available for sale securities continuous unrealized loss position for 12 months or longer, unrealized loss (4) (383)
Available for sale securities continuous unrealized loss position for less than 12 months, fair value 11,931 127,326
Available for sale securities continuous unrealized loss position for 12 months or longer, fair value $ 1,071 $ 30,609