Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Cash Flows from Operating Activities:
Net income	$ 102,854	$ 27,046
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of deferred financing costs, premiums and discounts on secured financing agreements	4,686	3,974
Amortization of discounts and deferred financing costs on senior notes	6,093	5,277
Accretion of net discount on investment securities	(4,257)	(3,373)
Accretion of net deferred loan fees and discounts	(7,519)	(8,696)
Share-based compensation	3,159	7,067
Share-based component of incentive fees	9,547	10,923
Change in fair value of fair value option investment securities	1,171	(753)
Change in fair value of consolidated VIEs	(20,677)	54,038
Change in fair value of servicing rights	8,433	6,739
Change in fair value of loans held-for-sale	(10,593)	(6,891)
Change in fair value of derivatives	2,900	23,557
Foreign currency (gain) loss, net	(4,829)	402
Loss (gain) on sale of investments and other assets	56	(245)
Impairment charges	758
Loan loss allowance, net	(305)	(761)
Depreciation and amortization	21,297	16,759
Earnings from unconsolidated entities	(2,987)	(4,065)
Distributions of earnings from unconsolidated entities	2,643	5,729
Loss on extinguishment of debt	5,916
Origination and purchase of loans held-for-sale, net of principal collections	(445,690)	(200,433)
Proceeds from sale of loans held-for-sale	179,296	256,964
Changes in operating assets and liabilities:
Related-party payable, net	(11,821)	(16,965)
Accrued and capitalized interest receivable, less purchased interest	(19,611)	(23,350)
Other assets	(1,855)	8,779
Accounts payable, accrued expenses and other liabilities	(14,686)	(30,593)
Net cash (used in) provided by operating activities	(196,021)	131,129
Cash Flows from Investing Activities:
Origination and purchase of loans held-for-investment	(621,135)	(472,237)
Proceeds from principal collections on loans	226,039	192,813
Proceeds from loans sold	37,079	97,882
Purchase of investment securities		(84,337)
Proceeds from sales of investment securities	10,434
Proceeds from principal collections on investment securities	76,050	22,344
Real estate business combinations, net of cash acquired		(73,639)
Additions to properties and other assets	(2,435)	(2,846)
Investment in unconsolidated entities		(11)
Distribution of capital from unconsolidated entities	3,127	914
Payments for purchase or termination of derivatives	(32,700)	(12,611)
Proceeds from termination of derivatives	17,331	7,910
Return of investment basis in purchased derivative asset	62	69
Net cash used in investing activities	(286,148)	(323,749)
Cash Flows from Financing Activities:
Proceeds from borrowings	1,205,691	991,192
Principal repayments on and repurchases of borrowings	(957,529)	(626,462)
Payment of deferred financing costs	(5,967)	(5,969)
Proceeds from common stock issuances	183	82
Payment of equity offering costs	(647)
Payment of dividends	(124,506)	(114,624)
Contributions from non-controlling interests		6,584
Distributions to non-controlling interests	(1,726)	(582)
Purchase of treasury stock		(19,723)
Issuance of debt of consolidated VIEs	4,759	596
Repayment of debt of consolidated VIEs	(57,445)	(55,729)
Distributions of cash from consolidated VIEs	30,956	7,545
Net cash provided by financing activities	93,769	182,910
Net decrease in cash, cash equivalents and restricted cash	(388,400)	(9,710)
Cash, cash equivalents and restricted cash, beginning of period	650,755	391,884	$ 391,884
Effect of exchange rate changes on cash	179	1,420
Cash, cash equivalents and restricted cash, end of period	262,534	383,594	$ 650,755
Supplemental disclosure of cash flow information:
Cash paid for interest	51,023	50,254
Income taxes paid	268	922
Supplemental disclosure of non-cash investing and financing activities:
Dividends declared, but not yet paid	125,479	114,572
Consolidation of VIEs (VIE asset/liability additions)	1,127,952	15,103,275
Deconsolidation of VIEs (VIE asset/liability reductions)	$ 1,528,137	2,591,268
Fair value of assets acquired, net of cash		221,125
Fair value of liabilities assumed		147,486
Net assets acquired from consolidated VIEs		$ 42,513