Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash Flows From Operating Activities:
Net Income (Loss)	$ 15,363,000	$ (215,112,000)	$ (249,905,000)
Adjustments to reconcile net loss to net cash and cash collateral posted to counterparties provided by (used in) operating activities:
Net amortization of premium on Agency Securities	48,127,000	53,322,000	53,909,000
Realized gain on sale of Agency Securities, available for sale	(10,952,000)	(143,877,000)	(9,611,000)
Credit loss expense	0	1,012,000	0
(Gain) loss on Agency Securities, trading	77,145,000	(19,557,000)	0
Loss on short sale of U.S. Treasury Securities	28,000	414,000	0
Stock based compensation	4,768,000	4,071,000	2,694,000
Changes in operating assets and liabilities:
Increase (decrease) in accrued interest receivable	2,263,000	21,828,000	(12,443,000)
Increase (decrease) in prepaid and other assets	883,000	7,074,000	(1,690,000)
Change in derivatives, at fair value	(134,704,000)	(100,692,000)	134,631,000
Increase (decrease) in accrued interest payable- repurchase agreements	(681,000)	(30,307,000)	21,664,000
Increase (decrease) in accounts payable and other accrued expenses	156,000	(1,019,000)	(821,000)
Net cash and cash collateral posted to counterparties provided by (used in) operating activities	11,738,000	(257,824,000)	(40,717,000)
Cash Flows From Investing Activities:
Purchases of Agency Securities	(1,265,942,000)	(5,838,937,000)	(8,937,989,000)
Principal repayments of Agency Securities	870,985,000	1,217,164,000	1,701,406,000
Principal repayments of Credit Risk and Non-Agency Securities	0	45,766,000	53,641,000
Proceeds from sales of Agency Securities	980,380,000	10,959,587,000	2,894,339,000
Disbursements on reverse repurchase agreements	(391,125,000)	(858,156,000)	0
Receipts from reverse repurchase agreements	391,125,000	858,156,000	0
Increase (decrease) in cash collateral posted by counterparties	126,356,000	29,746,000	(82,255,000)
Net cash and cash collateral posted to counterparties provided by (used in) investing activities	503,576,000	7,085,728,000	(4,389,771,000)
Cash Flows From Financing Activities:
Issuance of common stock, net of expenses	328,780,000	54,575,000	321,860,000
Proceeds from repurchase agreements	27,238,071,000	67,986,298,000	173,216,266,000
Principal repayments on repurchase agreements	(27,826,099,000)	(74,804,780,000)	(168,899,370,000)
Common stock dividends paid	(96,630,000)	(75,486,000)	(124,477,000)
Common stock repurchased, net	0	(777,000)	(16,965,000)
Net cash and cash collateral posted to counterparties provided by (used in) financing activities	(330,766,000)	(6,929,402,000)	4,471,455,000
Net increase (decrease) in cash and cash collateral posted to counterparties	184,548,000	(101,498,000)	40,967,000
Cash and cash collateral posted to counterparties - beginning of year	171,668,000	273,166,000	232,199,000
Cash and cash collateral posted to counterparties - end of year	356,216,000	171,668,000	273,166,000
Supplemental Disclosure:
Cash paid during the year for interest	21,262,000	183,365,000	425,746,000
Non-Cash Investing and Financing Activities
Payable for unsettled purchases	0	0	(358,712,000)
Net unrealized gain (loss) on available for sale Agency Securities	(61,106,000)	(33,577,000)	408,954,000
Amounts receivable for issuance of preferred stock	0	0	5,506,000
Amounts payable for common stock repurchased	0	0	(803,000)
Series A Preferred Stock
Cash Flows From Financing Activities:
Redemption of Preferred stock, net of expenses	0	0	(54,514,000)
Preferred dividends paid	0	0	(2,249,000)
Series B Preferred Stock
Cash Flows From Financing Activities:
Redemption of Preferred stock, net of expenses	0	(209,583,000)	0
Issuance of Preferred stock, net of expenses	0	0	44,289,000
Preferred dividends paid	0	(1,375,000)	(13,385,000)
Series C Preferred Stock
Cash Flows From Financing Activities:
Issuance of Preferred stock, net of expenses	36,585,000	130,138,000	0
Preferred dividends paid	(11,473,000)	(8,412,000)	0
Credit Risk and Non-Agency Securities
Adjustments to reconcile net loss to net cash and cash collateral posted to counterparties provided by (used in) operating activities:
Amortization (accretion)	0	(2,849,000)	(2,956,000)
(Gain) loss on debt securities, trading	0	189,555,000	24,396,000
Cash Flows From Investing Activities:
Purchases of trading securities	0	(237,928,000)	(138,767,000)
U.S. Treasury Securities Sold	0	889,057,000	0
Interest Only Securities
Adjustments to reconcile net loss to net cash and cash collateral posted to counterparties provided by (used in) operating activities:
Amortization (accretion)	0	0	1,924,000
(Gain) loss on debt securities, trading	0	0	(123,000)
Cash Flows From Investing Activities:
U.S. Treasury Securities Sold	0	0	18,822,000
US Treasury Securities
Adjustments to reconcile net loss to net cash and cash collateral posted to counterparties provided by (used in) operating activities:
Amortization (accretion)	(21,000)	84,000	(362,000)
(Gain) loss on debt securities, trading	9,363,000	(21,771,000)	(2,024,000)
Cash Flows From Investing Activities:
Purchases of trading securities	(987,887,000)	(4,621,776,000)	(1,685,058,000)
U.S. Treasury Securities Sold	$ 779,684,000	$ 4,643,049,000	$ 1,786,090,000