Fair Value of Financial Instruments - Schedule of Carrying Values and Fair Values of Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Carrying Value | Level 1
Assets
Cash and cash equivalents	$ 202,414	$ 255,664
Restricted cash	92,285	193,446
Liabilities
Convertible notes, net	293,699	292,993
Carrying Value | Level 2
Liabilities
Debt obligation facilities and other financing	4,112,303	4,045,578
Carrying Value | Level 3
Assets
Residential investor loans held-for-sale	14,830	14,414
Liabilities
ABS issued, net	0	58,431
Trust preferred securities and subordinated notes, net	138,917	138,906
Guarantee obligations	4,074	1,267
Carrying Value | Senior Notes | Level 1
Liabilities
Senior Notes	322,449	321,905
Estimated Fair Value | Level 1
Assets
Cash and cash equivalents	202,414	255,664
Restricted cash	92,285	193,446
Liabilities
Convertible notes, net	301,256	299,045
Estimated Fair Value | Level 2
Liabilities
Debt obligation facilities and other financing	4,112,887	4,046,266
Estimated Fair Value | Level 3
Assets
Residential investor loans held-for-sale	14,830	14,414
Liabilities
ABS issued, net	0	58,386
Trust preferred securities and subordinated notes, net	83,700	80,910
Guarantee obligations	2,564	2,627
Estimated Fair Value | Senior Notes | Level 1
Liabilities
Senior Notes	$ 317,803	$ 335,904