Leases - Additional Information (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021 USD ($) ft²	Jun. 30, 2020 USD ($)	Jun. 30, 2021 USD ($) ft²	Jun. 30, 2020 USD ($)	Dec. 31, 2020 USD ($)
Operating lease expense	$ 12,800		$ 24,800
Operating lease liabilities current	$ 45,340		$ 45,340		$ 0
Operating Lease, Liability, Current, Statement of Financial Position [Extensible List]	Accrued expenses and other current liabilities		Accrued expenses and other current liabilities
Operating lease liabilities	$ 206,376		$ 206,376
Operating leases, legally binding future minimum payments due					$ 287,716
Rent expense		$ 10,000		$ 20,000
Operating Lease, Lease Not Yet Commenced
Operating lease, lease not yet commenced, liability to be paid	$ 94,100		$ 94,100
Headquarter Office Lease
Operating lease term	9 years		9 years
Operating leases, legally binding future minimum payments due	$ 90,000		$ 90,000
Additional leased space | ft²	123,000		123,000
Minimum | Operating Lease, Lease Not Yet Commenced
Operating lease term	3 years		3 years
Maximum | Operating Lease, Lease Not Yet Commenced
Operating lease term	10 years		10 years