CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash Flows from Operating Activities
Net income	$ 53,249	$ 94,032
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of mortgage-backed and credit risk transfer securities premiums and (discounts), net	12,663	18,888
Realized and unrealized (gain) loss on derivative instruments, net	(145,479)	(28,356)
Realized and unrealized (gain) loss on credit derivatives, net	2,468	(14,148)
Gain (loss) on investments, net	(160,370)	(1,853)
(Income) loss from investments in unconsolidated ventures in excess of distributions received	(352)	1,760
Other amortization	(6,265)	(5,736)
Net loss on extinguishment of debt	26	4,711
(Gain) loss on foreign currency transactions, net	(1,800)	(513)
Changes in operating assets and liabilities:
(Increase) decrease in operating assets	1,334	(2,618)
Increase (decrease) in operating liabilities	562	(7,103)
Net cash provided by operating activities	76,776	62,770
Cash Flows from Investing Activities
Purchase of mortgage-backed and credit risk transfer securities	(298,859)	(1,846,444)
(Contributions to) distributions from investments in unconsolidated ventures, net	(1,532)	(2,636)
Purchase of exchange-traded fund	0	(3,508)
Principal payments from mortgage-backed and credit risk transfer securities	488,123	562,190
Proceeds from sale of mortgage-backed and credit risk transfer securities	0	180,809
Proceeds from/ (payments for) settlement or termination of forwards, swaps and futures, net	113,578	14,918
Net change in due from counterparties and collateral held payable	14,853	2,032
Principal payments from commercial loans held-for-investment	10,042	0
Origination and advances of commercial loans, net of origination fees	(698)	(2,014)
Net cash provided by (used in) investing activities	325,507	(1,094,653)
Cash Flows from Financing Activities
Proceeds from repurchase agreements	35,711,164	30,147,699
Principal repayments of repurchase agreements	(35,880,828)	(29,017,053)
Extinguishment of exchangeable senior notes	(143,433)	(153,750)
Payments of deferred costs	76	0
Payments of dividends and distributions	(58,587)	(50,924)
Net cash (used in) provided by financing activities	(371,760)	925,972
Net change in cash, cash equivalents and restricted cash	30,523	(105,911)
Cash, cash equivalents and restricted cash, beginning of period	89,001	161,788
Cash, cash equivalents and restricted cash, end of period	119,524	55,877
Supplement Disclosure of Cash Flow Information
Interest paid	73,811	51,058
Non-cash Investing and Financing Activities Information
Net change in unrealized gain (loss) on mortgage-backed and credit risk transfer securities	(123,080)	(17,139)
Dividends and distributions declared not paid	50,199	50,928
Net change in investment related payable (receivable)	80,688	174,217
Net change in repurchase agreements, not settled	0	(1,416)
Change in due from counterparties and collateral held payable	$ 0	$ 86,450