Leases, Commitments and Contingencies - Operating Leases - Additional Information (Detail) $ in Thousands			3 Months Ended
	Jan. 01, 2020 ft²	Jan. 01, 2019 USD ($) ft²	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	May 31, 2020 USD ($)
Commitments And Contingencies [Line Items]
Lease expire date			Jan. 31, 2022
Operating lease option to extend			true
Operating lease renewal term			5 years
Right-of-use operating asset | $		$ 5,300	$ 19,998	$ 25,064
Operating lease term of contract			3 years
Remaining operating lease asset | $					$ 2,300
Restricted Cash And Cash Equivalents Noncurrent | $			$ 700
Operating Lease One [Member]
Commitments And Contingencies [Line Items]
Office space rent under operating lease		63,017
Lease expire date		Aug. 31, 2024
Operating Lease Two [Member]
Commitments And Contingencies [Line Items]
Office space rent under operating lease		40,419
Lease expire date		Aug. 31, 2024
Operating Lease Three [Member]
Commitments And Contingencies [Line Items]
Office space rent under operating lease	15,525
Lease expire date	Nov. 30, 2024
Operating Lease Five [Member]
Commitments And Contingencies [Line Items]
Office space rent under operating lease	15,975
Lease expire date	Feb. 29, 2024
Minimum [Member]
Commitments And Contingencies [Line Items]
Operating lease remaining lease terms			1 year
Maximum [Member]
Commitments And Contingencies [Line Items]
Operating lease remaining lease terms			4 years