Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Cash Flows from Operating Activities:
Net income	$ 123,233	$ 112,071	$ 226,087	$ 139,117
Adjustments to reconcile net income to net cash used in operating activities:
Amortization of deferred financing costs, premiums and discounts on secured financing agreements			9,324	8,212
Amortization of discounts and deferred financing costs on senior notes			11,777	10,628
Accretion of net discount on investment securities			(8,007)	(7,349)
Accretion of net deferred loan fees and discounts			(16,194)	(23,362)
Share-based compensation			8,079	14,660
Share-based component of incentive fees			12,244	13,223
Change in fair value of fair value option investment securities	2,493	(1,319)	3,664	(2,072)
Change in fair value of consolidated VIEs			(42,593)	45,899
Change in fair value of servicing rights	8,001	12,191	16,434	18,930
Change in fair value of loans held-for-sale	(15,406)	(13,235)	(25,999)	(20,126)
Change in fair value of derivatives			39,223	2,332
Foreign currency (gain) loss, net			(17,590)	17,169
Gain on sale of investments and other assets			(5,127)	(155)
Impairment charges			867
Loan loss allowance, net	(2,694)	2,029	(2,999)	1,268
Depreciation and amortization			42,701	34,664
Earnings from unconsolidated entities	(29,465)	(4,479)	(32,452)	(8,544)
Distributions of earnings from unconsolidated entities			4,284	9,817
Bargain purchase gain				(8,406)
Loss on extinguishment of debt			5,916
Origination and purchase of loans held-for-sale, net of principal collections			(991,343)	(488,448)
Proceeds from sale of loans held-for-sale			470,478	475,333
Changes in operating assets and liabilities:
Related-party payable, net			(15,040)	(20,749)
Accrued and capitalized interest receivable, less purchased interest			(39,143)	(41,151)
Other assets			(2,391)	6,715
Accounts payable, accrued expenses and other liabilities			2,763	(29,055)
Net cash (used in) provided by operating activities			(345,037)	148,550
Cash Flows from Investing Activities:
Origination and purchase of loans held-for-investment			(1,228,952)	(997,421)
Proceeds from principal collections on loans			869,297	1,193,643
Proceeds from loans sold			37,079	121,276
Purchase of investment securities			(7,433)	(350,642)
Proceeds from sales of investment securities			11,134	1,269
Proceeds from principal collections on investment securities	10,209	25,200	86,259	47,544
Real estate business combinations, net of cash acquired				(91,186)
Proceeds from sale of properties			18,256
Additions to properties and other assets			(25,503)	(5,521)
Investment in unconsolidated entities				(3,854)
Distribution of capital from unconsolidated entities			3,235	1,244
Payments for purchase or termination of derivatives			(39,755)	(15,144)
Proceeds from termination of derivatives			22,981	27,447
Return of investment basis in purchased derivative asset			121	137
Net cash used in investing activities			(253,281)	(71,208)
Cash Flows from Financing Activities:
Proceeds from borrowings			2,134,245	2,059,599
Principal repayments on and repurchases of borrowings			(1,590,421)	(1,711,117)
Payment of deferred financing costs			(8,211)	(6,437)
Proceeds from common stock issuances			369	177
Payment of equity offering costs			(647)
Payment of dividends			(249,925)	(229,151)
Contributions from non-controlling interests				10,417
Distributions to non-controlling interests			(3,599)	(2,350)
Purchase of treasury stock				(19,723)
Issuance of debt of consolidated VIEs			10,188	596
Repayment of debt of consolidated VIEs			(79,099)	(147,523)
Distributions of cash from consolidated VIEs			38,840	22,986
Net cash provided by (used in) financing activities			251,740	(22,526)
Net (decrease) increase in cash, cash equivalents and restricted cash			(346,578)	54,816
Cash, cash equivalents and restricted cash, beginning of period			650,755	391,884	$ 391,884
Effect of exchange rate changes on cash			1,016	(749)
Cash, cash equivalents and restricted cash, end of period	305,193	445,951	305,193	445,951	$ 650,755
Supplemental disclosure of cash flow information:
Cash paid for interest			113,564	91,961
Income taxes paid			3,362	2,177
Supplemental disclosure of non-cash investing and financing activities:
Dividends declared, but not yet paid	$ 125,587	$ 115,013	125,587	115,013
Consolidation of VIEs (VIE asset/liability additions)			1,127,952	16,850,221
Deconsolidation of VIEs (VIE asset/liability reductions)			2,108,589	5,126,980
Net assets acquired from consolidated VIEs			19,652	102,976
Settlement of loans transferred as secured borrowings			$ 35,000
Fair value of assets acquired, net of cash				270,021
Fair value of liabilities assumed				$ 170,429