Quarterly report pursuant to Section 13 or 15(d)

Fair Value Measurement - Summary of Contractual Maturities of Available for Sale Securities (Detail)

v3.19.3
Fair Value Measurement - Summary of Contractual Maturities of Available for Sale Securities (Detail)
$ in Thousands
Sep. 30, 2019
USD ($)
Schedule Of Available For Sale Securities [Line Items]  
Available for sale securities, contractual maturities less than 1 year $ 97,025
Available for sale securities, contractual maturities between 1 to 5 years 134,969
Available for sale securities, contractual maturities between 5 to 10 years 49,466
Available for sale securities, contractual maturities, Total 281,460
Corporate Bonds [Member]  
Schedule Of Available For Sale Securities [Line Items]  
Available for sale securities, contractual maturities less than 1 year 30,040
Available for sale securities, contractual maturities between 1 to 5 years 122,786
Available for sale securities, contractual maturities between 5 to 10 years 21,458
Available for sale securities, contractual maturities, Total 174,284
U.S. Treasuries [Member]  
Schedule Of Available For Sale Securities [Line Items]  
Available for sale securities, contractual maturities less than 1 year 36,232
Available for sale securities, contractual maturities between 1 to 5 years 804
Available for sale securities, contractual maturities, Total 37,036
U.S. Government Agency Securities [Member]  
Schedule Of Available For Sale Securities [Line Items]  
Available for sale securities, contractual maturities less than 1 year 5,499
Available for sale securities, contractual maturities between 1 to 5 years 6,443
Available for sale securities, contractual maturities between 5 to 10 years 28,008
Available for sale securities, contractual maturities, Total 39,950
Money Market Funds [Member]  
Schedule Of Available For Sale Securities [Line Items]  
Available for sale securities, contractual maturities less than 1 year 25,204
Available for sale securities, contractual maturities, Total 25,204
Supranational Bonds [Member]  
Schedule Of Available For Sale Securities [Line Items]  
Available for sale securities, contractual maturities between 1 to 5 years 4,802
Available for sale securities, contractual maturities, Total 4,802
Asset Backed Securities [Member]  
Schedule Of Available For Sale Securities [Line Items]  
Available for sale securities, contractual maturities between 1 to 5 years 134
Available for sale securities, contractual maturities, Total 134
Municipal Bonds [Member]  
Schedule Of Available For Sale Securities [Line Items]  
Available for sale securities, contractual maturities less than 1 year 50
Available for sale securities, contractual maturities, Total $ 50