Summary of Significant Accounting Policies - Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Revenue from External Customer
Revenues	$ 585,844	$ 755,351	$ 1,106,643	$ 1,433,599
Management services, servicing fees and other
Revenue from External Customer
Revenues	240,660	233,685	452,952	466,804
Leasing and other commissions
Revenue from External Customer
Revenues	203,611	212,825	396,917	411,778
Investment sales
Revenue from External Customer
Revenues	77,604	209,053	149,597	361,167
Commercial mortgage origination, net
Revenue from External Customer
Revenues	$ 63,969	$ 99,788	$ 107,177	$ 193,850