Quarterly report pursuant to Section 13 or 15(d)

Financial Instruments - Amortized Cost and Fair Value of Available-for-Sale Securities by Contractual Maturity (Detail)

v3.19.3
Financial Instruments - Amortized Cost and Fair Value of Available-for-Sale Securities by Contractual Maturity (Detail) - USD ($)
$ in Thousands
Sep. 30, 2019
Dec. 31, 2018
Amortized cost    
Maturing within one year, Amortized cost $ 246,860 $ 287,755
Maturing in one to five years, Amortized cost 33,568 23,169
Total available-for-sale securities, Amortized cost 280,428 310,924
Estimated Fair value    
Maturing within one year, Estimated fair value 246,976 287,469
Maturing in one to five years, Estimated fair value 33,685 23,115
Total available-for-sale securities, Estimated fair value $ 280,661 $ 310,584