Revenues from Contracts with Customers - Schedule of Revenues from Contracts with Customers and Our Other Sources of Revenues (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue
Revenues from contracts with customers:	$ 278,135	$ 463,603	$ 672,066	$ 836,959
Revenues	383,718	551,478	867,647	999,134
Gains from mortgage banking activities/originations, net
Disaggregation of Revenue
Other sources of revenue:	69,071	45,091	119,494	76,437
Servicing fees and other
Disaggregation of Revenue
Other sources of revenue:	36,512	42,784	76,087	85,738
Leasing and other commissions
Disaggregation of Revenue
Revenues from contracts with customers:	120,079	217,381	260,517	389,852
Revenues	120,079	217,381	260,517	389,852
Capital markets commissions
Disaggregation of Revenue
Revenues from contracts with customers:	52,959	128,750	180,882	231,547
Management services
Disaggregation of Revenue
Revenues from contracts with customers:	$ 105,097	$ 117,472	$ 230,667	$ 215,560