Consolidated Statements of Cash Flows (Unaudited) - USD ($)	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash Flows From Operating Activities:
Net Income (Loss)	$ (358,586,000)	$ 106,013,000
Adjustments to reconcile net income (loss) to net cash and cash collateral posted to counterparties provided by (used in) operating activities:
Net amortization of premiums on investments	35,260,000	26,631,000
Accretion of net discount on Credit Risk and Non-Agency Securities	(2,266,000)	(2,175,000)
Realized gain (loss) on sale of Agency Securities	(1,615,000)	89,055,000
Other than temporary impairment of Agency Securities	0	12,090,000
Stock based compensation	2,039,000	1,953,000
Changes in operating assets and liabilities:
Increase in accrued interest receivable	(14,220,000)	(233,000)
(Increase) decrease in prepaid and other assets	(111,000)	76,000
Change in derivatives, at fair value	195,421,000	(205,710,000)
Increase in accrued interest payable- repurchase agreements	3,736,000	3,242,000
Increase in accounts payable and other accrued expenses	2,570,000	3,328,000
Net cash and cash collateral posted to counterparties provided by (used in) operating activities	(112,313,000)	47,375,000
Cash Flows From Investing Activities:
Purchases of Agency Securities	(7,971,429,000)	(3,455,523,000)
Principal repayments of Agency Securities	1,036,135,000	527,643,000
Principal repayments of Credit Risk and Non-Agency Securities	29,186,000	26,624,000
Proceeds from sales of Agency Securities	2,230,377,000	3,165,570,000
(Decrease) increase in cash collateral posted by counterparties	(71,903,000)	202,448,000
Net cash and cash collateral posted to counterparties provided by (used in) investing activities	(4,638,317,000)	362,817,000
Cash Flows From Financing Activities:
Issuance of common stock, net of expenses	321,860,000	8,999,000
Proceeds from repurchase agreements	143,170,110,000	144,332,820,000
Principal repayments on repurchase agreements	(138,528,667,000)	(144,670,003,000)
Common stock dividends paid	(94,300,000)	(72,481,000)
Common stock repurchased	(16,965,000)	0
Net cash and cash collateral posted to counterparties provided by (used in) financing activities	4,805,306,000	(410,805,000)
Net Increase (decrease) in cash and cash collateral posted to counterparties	54,676,000	(613,000)
Cash and cash collateral posted to counterparties - beginning of period	232,199,000	282,394,000
Cash and cash collateral posted to counterparties - end of period	286,875,000	281,781,000
Supplemental Disclosure:
Cash paid during the period for interest	342,374,000	157,928,000
Non-Cash Investing and Financing Activities:
Net unrealized gain (loss) on available for sale Agency Securities	451,173,000	(253,267,000)
Amounts receivable for issuance of Preferred B stock	753,000	0
Series A Preferred Stock
Cash Flows From Financing Activities:
Redemption of Series A Preferred stock, net of expenses	(54,514,000)	0
Preferred stock dividends paid	(2,249,000)	(3,373,000)
Series B Preferred Stock
Cash Flows From Financing Activities:
Issuance of Series B Preferred stock, net of expenses	19,725,000	2,632,000
Preferred stock dividends paid	(9,694,000)	(9,399,000)
Interest-Only Securities
Adjustments to reconcile net income (loss) to net cash and cash collateral posted to counterparties provided by (used in) operating activities:
Net amortization of premiums on investments	1,922,000	3,180,000
Gain (loss) on securities	(123,000)	(58,000)
Cash Flows From Investing Activities:
Proceeds from sales of held-for-investment securities	18,822,000	0
US Treasury Securities
Adjustments to reconcile net income (loss) to net cash and cash collateral posted to counterparties provided by (used in) operating activities:
Net amortization of premiums on investments	(361,000)	(474,000)
Gain (loss) on securities	(2,024,000)	6,391,000
(Gain) loss on U.S. Treasury Securities	(2,024,000)	6,391,000
Cash Flows From Investing Activities:
Purchases of Credit Risk, Non-Agency Securities, and U.S. Treasury Securities	(1,685,058,000)	(765,828,000)
Proceeds from sales of held-for-investment securities	1,786,090,000	661,883,000
Credit Risk and Non-Agency Securities
Adjustments to reconcile net income (loss) to net cash and cash collateral posted to counterparties provided by (used in) operating activities:
Gain (loss) on securities	26,045,000	4,066,000
Cash Flows From Investing Activities:
Purchases of Credit Risk, Non-Agency Securities, and U.S. Treasury Securities	$ (10,537,000)	$ 0