Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Cash flows from operating activities:
Net income (loss)	$ (381,855)	$ 27,876
Adjustments to reconcile net income (loss) to net cash used in operating activities:
Premium amortization and (discount accretion), net	1,837	357
Amortization of deferred financing costs	646	192
Amortization of discount on convertible senior notes	273	137
Restricted stock amortization	165	70
Interest payments and basis recovered on MAC interest rate swaps	202	337
Premium on purchase of Residential Whole Loans	(3,858)	(4,882)
Premium on purchase of securitized commercial loans	0	(3,769)
Unrealized (gain) loss, net	296,111	(50,781)
Realized loss on sale of real estate owned ("REO")	267	0
Unrealized (gain) loss on derivative instruments, net	8,807	(11,313)
Other than temporary impairment	0	1,232
Realized (gain) loss on investments, net	(89,453)	5,105
Loss on derivatives, net	135	4,889
Changes in operating assets and liabilities:
Decrease in interest receivable	4,608	1,295
(Increase) decrease in other assets	(1,583)	1,219
(Decrease) increase in interest payable	(8,572)	1,788
Increase in accounts payable and accrued expenses	3,119	356
Increase (decrease) in payable to affiliate	1,089	(401)
Net cash used in operating activities	(168,062)	(26,293)
Cash flows from investing activities:
Purchase of securities	(320,997)	(24,175)
Proceeds from sale of securities	1,685,381	215,710
Proceeds from sale of REO	1,347	0
Principal repayments and basis recovered on securities	25,454	17,347
Purchase of Residential Whole Loans	(109,481)	(244,317)
Principal repayments on Residential Whole Loans	77,217	28,293
Purchase of commercial loans	0	(121,188)
Principal repayments on commercial loans	37,638	165
Purchase of securitized commercial loans	0	(900,000)
Principal repayments on securitized commercial loans	154,702	988,714
Principal repayments on Residential Bridge Loans	6,372	80,006
Premium for credit default swaps, net	(566)	(367)
Net settlements of TBAs	883	0
(Payments on) Proceeds from termination of futures, net	0	(4,503)
Interest payments and basis recovered on MAC interest rate swaps	(202)	(337)
Due from counterparties	(4,120)	0
Payments made on reverse repurchase agreements, net	(24,826)	0
Net cash provided by investing activities	1,528,802	35,348
Cash flows from financing activities:
Payment of offering costs	(3)	(174)
Repurchase of common stock	(578)	0
Proceeds from offering to non-controlling interest, net of offering costs	42	0
Proceeds from repurchase agreement borrowings	5,786,714	5,764,802
Repayments of repurchase agreement borrowings	(7,057,810)	(5,667,038)
Proceeds from other liabilities	12,549	0
Proceeds from securitized debt	92,828	838,469
Repayments of securitized debt	(208,379)	(937,805)
Due from counterparties, net	(14,603)	1,602
Due to counterparties, net	24,102	3,576
Increase in other liabilities	(19,720)	15,369
Dividends paid on common stock	(16,590)	(14,915)
Net cash (used in) provided by financing activities	(1,401,448)	3,886
Net (decrease) increase in cash, cash equivalents and restricted cash	(40,708)	12,941
Cash, cash equivalents and restricted cash, beginning of period	84,279	77,795
Cash, cash equivalents and restricted cash, end of period	43,571	90,736
Supplemental disclosure of operating cash flow information:
Interest paid	43,800	35,519
Supplemental disclosure of non-cash financing/investing activities:
Securities sold, not settled	47,475	0
Assets of deconsolidated VIE	150,804	0
Liabilities of deconsolidated VIE	143,952	0
Mortgage-backed securities recorded upon deconsolidation	6,852	0
Net unsettled TBAs	612	0
Dividends to non-controlling interest, not paid	0	2
Principal payments of Residential Whole Loans, not settled	22,181	10,546
Principal payments of Residential Bridge Loans, not settled	2,557	22,014
Other assets - Transfer of Bridge Loans to REO	489	0
Total cash, cash equivalents and restricted cash shown in the Consolidated Statements of Cash Flows	$ 43,571	$ 90,736