Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Schedule Of Pre Tax Income [Line Items]
Pre-tax income from U.S. operations	$ 288,300	$ 190,400	$ 168,500
U.S. federal tax at statutory rate	21.00%	21.00%	21.00%
Unrecognized tax benefits	$ 16,317	$ 6,831	$ 4,718	$ 2,650
Recognized penalties and interest on unrecognized tax benefits	3,700	600	400
Penalties and interest accrued on unrecognized tax benefits	$ 4,900	1,200
New York State [Member] | Earliest Tax Year [Member]
Schedule Of Pre Tax Income [Line Items]
Income tax year under examination	2010
New York State [Member] | Latest Tax Year [Member]
Schedule Of Pre Tax Income [Line Items]
Income tax year under examination	2017
New York City [Member] | Earliest Tax Year [Member]
Schedule Of Pre Tax Income [Line Items]
Income tax year under examination	2016
New York City [Member] | Latest Tax Year [Member]
Schedule Of Pre Tax Income [Line Items]
Income tax year under examination	2018
Foreign Country [Member]
Schedule Of Pre Tax Income [Line Items]
Pre-tax income from foreign operations	$ 86,100	$ 67,000	$ 49,600