Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities
Net income	$ 140,414	$ 307,393	$ 285,813
Adjustments to reconcile net income to net cash provided by operating activities
Non-cash compensation expense	34,532	30,656	28,154
Satisfaction of management and incentive fees in stock	19,277
Amortization of deferred fees on loans and debt securities	(56,844)	(57,926)	(47,093)
Amortization of deferred financing costs and premiums/discount on debt obligations	37,403	32,195	28,284
Increase in current expected credit loss reserve	167,653
Unrealized (gain) loss on assets denominated in foreign currencies, net	(3,366)	881	(165)
Unrealized (gain) loss on derivative financial instruments, net	(867)	(1,071)	327
Realized loss (gain) on derivative financial instruments, net	1,364	11	(349)
Changes in assets and liabilities, net
Other assets	3,352	(7,355)	(23,352)
Other liabilities	(6,311)	(747)	18,383
Net cash provided by operating activities	336,607	304,037	290,002
Cash flows from investing activities
Origination and fundings of loans receivable	(1,896,276)	(6,890,249)	(7,890,051)
Principal collections and sales proceeds from loans receivable and debt securities	1,850,003	4,940,194	3,084,747
Loan contributed to securitization			512,002
Investment in debt securities held-to-maturity			(95,937)
Origination and exit fees received on loans receivable	21,275	66,558	104,408
Receipts under derivative financial instruments	90,427	49,673	47,527
Payments under derivative financial instruments	(133,430)	(6,524)	(18,475)
Collateral deposited under derivative agreements	(346,640)	(59,720)	(38,990)
Return of collateral deposited under derivative agreements	326,390	28,920	43,110
Net cash used in investing activities	(88,251)	(1,871,148)	(4,251,659)
Cash flows from financing activities
Borrowings under secured debt agreements	2,567,834	6,322,165	9,100,019
Repayments under secured debt agreements	(4,690,607)	(5,526,989)	(5,313,679)
Proceeds from issuance of securitized debt obligations	2,051,875
Repayment of securitized debt obligations	(300,879)	(102,478)
Borrowings under asset-specific debt agreements	161,960	247,295	83,833
Repayments under asset-specific debt agreements	(82,754)		(99,391)
Proceeds from sale of loan participations		21,346	99,696
Repayment of loan participations		(115,874)	(85,875)
Net proceeds from issuance of secured term loan	315,438	748,414
Repayments of secured term loan	(9,113)	(3,122)
Payment of deferred financing costs	(47,345)	(39,370)	(25,006)
Contributions from non-controlling interests	8,431	51,418	9,315
Distributions to non-controlling interests	(15,024)	(41,629)	(5,907)
Net proceeds from issuance of convertible notes			214,775
Repayment of convertible notes			(219,232)
Net proceeds from issuance of class A common stock	278,322	372,337	476,420
Dividends paid on class A common stock	(348,907)	(320,961)	(277,260)
Net cash (used in) provided by financing activities	(110,769)	1,612,552	3,957,708
Net increase (decrease) in cash and cash equivalents	137,587	45,441	(3,949)
Cash and cash equivalents at beginning of year	150,090	105,662	102,518
Effects of currency translation on cash and cash equivalents	2,293	(1,013)	7,093
Cash and cash equivalents at end of year	289,970	150,090	105,662
Supplemental disclosure of cash flows information
Payments of interest	(312,093)	(425,801)	(318,919)
(Payments) receipts of income taxes	(232)	109	(554)
Supplemental disclosure of non-cash investing and financing activities
Dividends declared, not paid	(91,004)	(83,702)	(76,530)
Satisfaction of management and incentive fees in stock	19,277
Loan principal payments held by servicer, net	$ 19,460	$ 49,584	$ 4,855