General and Administrative Expenses and Other Expenses - Components of General and Administrative Expenses and Other Expenses (Details) - USD ($) $ in Thousands		3 Months Ended			6 Months Ended
	Oct. 15, 2019	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Business Acquisition [Line Items]
Fixed compensation expense		$ 11,818		$ 9,252	$ 26,502	$ 17,349
Variable compensation expense		3,278		4,021	3,289	8,423
Equity compensation expense		3,262		4,024	5,257	6,977
Acquisition-related equity compensation expense		1,212		0	2,424	0
Systems and consulting		2,395		2,536	5,607	4,364
Loan acquisition costs		2,152		1,516	6,878	3,101
Office costs		1,887		1,585	3,995	2,889
Accounting and legal		2,788		960	5,004	2,085
Corporate costs		626		545	1,297	1,219
Other operating expenses		674		1,816	2,507	3,007
Total General and Administrative Expenses		30,092		26,255	62,760	49,414
Goodwill impairment expense		0	$ 89,000	0	88,675	0
Amortization of purchase-related intangible assets		3,873		1,900	8,179	2,711
Contingent consideration expense		134		311	446	311
Other		1,076		241	(802)	468
Total Other Expenses		5,083		2,452	96,498	3,490
Total General and Administrative Expenses and Other Expenses		$ 35,175		$ 28,707	$ 159,258	$ 52,904
CoreVest
Business Acquisition [Line Items]
Restricted stock awards (in shares)	588,260
Restricted stock awards	$ 10,000
Contingent consideration performance term	2 years