Fair Value of Financial Instruments - Schedule of Major Categories of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Commercial Paper [Member]
Assets:
Assets	$ 130,966	$ 99,929
Certificates of Deposit [Member]
Assets:
Assets	25,000	80,000
Level 2 [Member] | Commercial Paper [Member]
Assets:
Assets	130,966	99,929
Level 2 [Member] | Certificates of Deposit [Member]
Assets:
Assets	25,000	80,000
Interest Rate Swap [Member]
Liabilities:
Liabilities	1,875	2,738
Interest Rate Swap [Member] | Level 2 [Member]
Liabilities:
Liabilities	$ 1,875	$ 2,738