Consolidated Statements of Cash Flows - USD ($)	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Operating activities:
Net income (loss)	$ 137,084,000	$ (207,803,000)
Adjustments to reconcile net income (loss) to cash provided by operating activities:
Decrease (increase) in accrued interest receivable	10,869,000	(3,075,000)
Decrease in accrued interest payable	(14,526,000)	(3,122,000)
Loss on derivative instruments, net	196,156,000	229,941,000
(Gain) loss on sale of investments, net	(298,728,000)	5,755,000
Fair value adjustments, net	(154,000)	42,000
Amortization of investment premiums, net	96,018,000	98,327,000
Other amortization and depreciation, net	1,428,000	1,186,000
Stock-based compensation expense	1,299,000	899,000
Change in other assets and liabilities, net	530,000	(6,000)
Net cash and cash equivalents provided by operating activities	129,976,000	122,144,000
Investing activities:
Purchase of investments	(2,436,953,000)	(2,833,348,000)
Principal payments received on investments	344,055,000	347,565,000
Proceeds from sales of investments	4,401,909,000	1,033,066,000
Principal payments received on mortgage loans held for investment	2,170,000	1,677,000
Net payments on derivatives, including terminations	(197,932,000)	(229,001,000)
Other investing activities	0	(183,000)
Net cash and cash equivalents provided by (used in) investing activities	2,113,249,000	(1,680,224,000)
Financing activities:
Borrowings under repurchase agreements	28,304,165,000	93,107,875,000
Repayments of repurchase agreement borrowings	(30,461,830,000)	(91,502,990,000)
Principal payments on non-recourse collateralized financing	(2,107,000)	(517,000)
Proceeds from issuance of preferred stock	107,988,000	19,924,000
Proceeds from issuance of common stock	0	63,889,000
Payments for Repurchase of Redeemable Preferred Stock	100,000,000	0
Cash paid for stock issuance costs	0	(185,000)
Payments for Repurchase of Common Stock	372,000	25,034,000
Payments related to tax withholding for stock-based compensation	(245,000)	(296,000)
Dividends paid	(40,151,000)	(54,355,000)
Net cash and cash equivalents (used in) provided by financing activities	(2,192,552,000)	1,608,311,000
Net increase in cash, cash equivalents, and restricted cash	50,673,000	50,231,000
Cash, cash equivalents, and restricted cash at beginning of period	134,230,000	88,704,000
Cash, cash equivalents, and restricted cash at end of period	184,903,000	138,935,000
Supplemental Disclosure of Cash Activity:
Cash paid for interest	$ 44,216,000	$ 91,624,000