Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Cash Flows from Operating Activities:
Net income	$ 152,961	$ 132,446	$ 86,692	$ 208,954
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Amortization of deferred financing costs, premiums and discounts on secured borrowings			19,552	17,439
Amortization of discounts and deferred financing costs on unsecured senior notes			3,938	3,849
Accretion of net discount on investment securities			(6,123)	(7,857)
Accretion of net deferred loan fees and discounts			(20,840)	(16,112)
Share-based compensation			16,144	13,388
Manager fees paid in stock			36,046	10,977
Change in fair value of investment securities	(827)	(667)	(3,331)	(729)
Change in fair value of consolidated VIEs			62,175	(11,957)
Change in fair value of servicing rights			2,962	1,683
Change in fair value of loans	(34,450)	(21,891)	(18,316)	(33,157)
Change in fair value of derivatives			10,531	4,496
Foreign currency loss, net			27,313	1,470
Gain on sale of investments and other assets			(6,768)	(7,000)
Impairment charges on properties and related intangibles				1,392
Credit loss provision, net	10,202	2,518	58,871	3,281
Depreciation and amortization			47,137	57,416
(Earnings) loss from unconsolidated entities	(28,776)	(8,817)	(28,873)	34,383
Distributions of earnings from unconsolidated entities			888	8,056
Loss on extinguishment of debt	2,207	2,816	2,377	6,114
Origination and purchase of loans held-for-sale, net of principal collections			(740,649)	(1,600,100)
Proceeds from sale of loans held-for-sale			1,340,833	928,747
Changes in operating assets and liabilities:
Related-party payable, net			(19,984)	(22,899)
Accrued and capitalized interest receivable, less purchased interest			(80,702)	(54,261)
Other assets			(16,372)	(18,270)
Accounts payable, accrued expenses and other liabilities			(3,763)	(12,153)
Net cash provided by (used in) operating activities			769,738	(482,850)
Cash Flows from Investing Activities:
Origination and purchase of loans held-for-investment			(1,666,903)	(2,051,646)
Proceeds from principal collections on loans			999,254	1,342,698
Proceeds from loans sold			435,097	843,344
Purchase and funding of investment securities			(16,120)
Proceeds from sales of investment securities			7,940	3,978
Proceeds from principal collections on investment securities	36,920	65,281	50,479	73,035
Proceeds from sales of real estate			23,805	1,841
Purchases and additions to properties and other assets			(13,914)	(10,425)
Investment in unconsolidated entities			(3,130)	(785)
Proceeds from sale of interest in unconsolidated entities			10,313
Distribution of capital from unconsolidated entities			206	10,041
Payments for purchase or termination of derivatives			(80,911)	(20,212)
Proceeds from termination of derivatives			13,128	8,899
Net cash (used in) provided by investing activities			(240,756)	200,768
Cash Flows from Financing Activities:
Proceeds from borrowings			3,686,932	3,271,785
Principal repayments on and repurchases of borrowings			(3,716,558)	(2,679,056)
Payment of deferred financing costs			(7,564)	(18,388)
Proceeds from common stock issuances			369	379
Payment of equity offering costs			(15)	(8)
Payment of dividends			(271,624)	(267,301)
Contributions from non-controlling interests			9,406	4,636
Distributions to non-controlling interests			(76,514)	(30,854)
Purchase of treasury stock			(28,830)
Issuance of debt of consolidated VIEs			24,376	100,224
Repayment of debt of consolidated VIEs			(236,336)	(91,808)
Distributions of cash from consolidated VIEs			36,989	21,411
Net cash (used in) provided by financing activities			(579,369)	311,020
Net (decrease) increase in cash, cash equivalents and restricted cash			(50,387)	28,938
Cash, cash equivalents and restricted cash, beginning of period			574,031	487,865	$ 487,865
Effect of exchange rate changes on cash			487	(605)
Cash, cash equivalents and restricted cash, end of period	524,131	516,198	524,131	516,198	$ 574,031
Supplemental disclosure of cash flow information:
Cash paid for interest			202,648	252,392
Income taxes paid			657	7,270
Supplemental disclosure of non-cash investing and financing activities:
Dividends declared, but not yet paid	$ 137,242	$ 135,615	137,242	135,615
Consolidation of VIEs (VIE asset/liability additions)			3,077,357	4,104,135
Deconsolidation of VIEs (VIE asset/liability reductions)				303,827
Reclassification of residential loans held-for-investment to held-for-sale			422,691
Loan principal collections temporarily held at master servicer			12,274
Redemption of Class A Units for common stock			$ 8,538	16,373
Settlement of 2019 Convertible Notes in shares				75,525
Settlement of loans transferred as secured borrowings				74,692
Net assets acquired through foreclosure				27,416
Lease liabilities arising from obtaining right-of-use assets				$ 7,092