Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Cash Flows from Operating Activities:
Net (loss) income	$ (66,269)	$ 76,508
Adjustments to reconcile net (loss) income to net cash provided by (used in) operating activities:
Amortization of deferred financing costs, premiums and discounts on secured borrowings	9,634	9,183
Amortization of discounts and deferred financing costs on unsecured senior notes	1,962	1,933
Accretion of net discount on investment securities	(2,783)	(2,755)
Accretion of net deferred loan fees and discounts	(12,080)	(7,526)
Share-based compensation	8,800	6,363
Share-based component of incentive fees	9,080	10,977
Change in fair value of investment securities	(2,504)	(62)
Change in fair value of consolidated VIEs	80,683	133
Change in fair value of servicing rights	393	767
Change in fair value of loans	16,134	(11,266)
Change in fair value of derivatives	(7,617)	3,396
Foreign currency loss (gain), net	34,486	(5,547)
Gain on sale of investments and other assets	(296)	(4,485)
Impairment charges on properties and related intangibles		120
Credit loss provision, net	48,669	763
Depreciation and amortization	23,864	28,889
(Earnings) loss from unconsolidated entities	(97)	43,200
Distributions of earnings from unconsolidated entities	27	3,661
Loss on extinguishment of debt	(170)	(3,298)
Origination and purchase of loans held-for-sale, net of principal collections	(621,832)	(719,589)
Proceeds from sale of loans held-for-sale	751,140	561,702
Changes in operating assets and liabilities:
Related-party payable, net	(1,659)	(20,098)
Accrued and capitalized interest receivable, less purchased interest	(31,465)	(22,536)
Other assets	(40,944)	(26,760)
Accounts payable, accrued expenses and other liabilities	(6,764)	(22,987)
Net cash provided by (used in) operating activities	190,732	(92,718)
Cash Flows from Investing Activities:
Origination and purchase of loans held-for-investment	(1,252,745)	(1,287,001)
Proceeds from principal collections on loans	812,187	556,058
Proceeds from loans sold	39,019	500,271
Purchase and funding of investment securities	(5,729)
Proceeds from sales of investment securities	7,940	3,228
Proceeds from principal collections on investment securities	13,559	7,754
Proceeds from sales of real estate		1,463
Purchases and additions to properties and other assets	(7,056)	(8,526)
Investment in unconsolidated entities	(3,100)	(510)
Distribution of capital from unconsolidated entities	153	886
Payments for purchase or termination of derivatives	(67,323)	(3,896)
Proceeds from termination of derivatives	8,912	692
Net cash used in investing activities	(454,183)	(229,581)
Cash Flows from Financing Activities:
Proceeds from borrowings	2,756,915	2,310,902
Principal repayments on and repurchases of borrowings	(1,923,754)	(1,778,819)
Payment of deferred financing costs	(3,577)	(4,706)
Proceeds from common stock issuances	153	167
Payment of equity offering costs	(14)	(5)
Payment of dividends	(135,889)	(132,515)
Contributions from non-controlling interests	9,406	95
Distributions to non-controlling interests	(66,476)	(6,952)
Purchase of treasury stock	(28,830)
Issuance of debt of consolidated VIEs	24,376	33,678
Repayment of debt of consolidated VIEs	(36,953)	(52,856)
Distributions of cash from consolidated VIEs	24,723	11,683
Net cash provided by financing activities	620,080	380,672
Net increase in cash, cash equivalents and restricted cash	356,629	58,373
Cash, cash equivalents and restricted cash, beginning of period	574,031	487,865	$ 487,865
Effect of exchange rate changes on cash	733	(254)
Cash, cash equivalents and restricted cash, end of period	931,393	545,984	$ 574,031
Supplemental disclosure of cash flow information:
Cash paid for interest	109,341	129,349
Income taxes paid	569	484
Supplemental disclosure of non-cash investing and financing activities:
Dividends declared, but not yet paid	135,994	134,953
Consolidation of VIEs (VIE asset/liability additions)	2,477,422	3,280,065
Deconsolidation of VIEs (VIE asset/liability reductions)		45,910
Reclassification of residential loans held-for-investment to held-for-sale	422,691
Loan principal collections temporarily held at master servicer	9,779
Redemption of Class A Units for common stock	$ 8,538
Settlement of 2019 Convertible Notes in shares		75,525
Settlement of loans transferred as secured borrowings		74,692
Net assets acquired through foreclosure		8,963
Unsettled infrastructure loan sales		$ 68,564