CONSOLIDATED STATEMENTS OF CASH FLOWS, (Unaudited)	3 Months Ended
	Mar. 31, 2021 USD ($)	Mar. 31, 2020 USD ($)
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)	$ (29,369,000)	$ (91,199,000)
Adjustments to reconcile net income (loss) to net cash (used in) provided by operating activities:
Stock based compensation and equity plan amortization	259,000	59,000
Realized and unrealized (gains) losses on mortgage-backed securities	96,263,000	25,348,000
Derivative, Gain (Loss) on Derivative, Net	(45,914,000)	64,613,000
Changes in operating assets and liabilities
Accrued interest receivable	(1,050,000)	2,350,000
Other assets	(588,000)	(655,000)
Accrued interest payable	(236,000)	(7,287,000)
Other liabilities	5,318,000	(223,000)
Due to affiliates	80,000	(102,000)
NET CASH (USED IN) PROVIDED BY OPERATING ACTIVITIES	24,763,000	(7,096,000)
From mortgage-backed securities investments
Purchases	(1,764,082,000)	(1,334,350,000)
Sales	988,523,000	1,808,867,000
Principal repayments	123,880,000	142,259,000
Payments on net settlement of to-be-announced securities	(3,289,000)	(7,602,000)
Purchase of interest rate swaptions, net of margin cash received	7,385,000	45,458,000
NET CASH USED IN INVESTING ACTIVITIES	(662,353,000)	563,716,000
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from repurchase agreements	7,517,156,000	13,602,710,000
Principal payments on repurchase agreements	(6,931,062,000)	(14,240,566,000)
Cash dividends	(16,030,000)	(15,416,000)
Proceeds From Issuance Of Common Stock, net of issuance costs	96,908,000	19,447,000
Payments Related To Tax Withholding For Share Based Compensation	297,000	0
NET CASH PROVIDED BY FINANCING ACTIVITIES	666,675,000	(633,825,000)
NET INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	29,085,000	(77,205,000)
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, beginning of period	299,506,000	278,655,000
CASH, CASH EQUIVALENTS AND RESTRICTED CASH, end of period	328,591,000	201,450,000
Cash paid during the period for:
Interest Paid	2,176,000	23,809,000
SUPPLEMENTAL DISCLOSURES OF NONCASH FINANCING ACTIVITIES:
Securities acquired settled in later period	217,758,000	3,450,000
Securities Sold Settled In Later Period	154,977,000	0
Interest Rate Swaption [Member]
Adjustments to reconcile net income (loss) to net cash (used in) provided by operating activities:
Derivative, Gain (Loss) on Derivative, Net	(13,903,000)	2,589,000
Swap [Member]
Adjustments to reconcile net income (loss) to net cash (used in) provided by operating activities:
Derivative, Gain (Loss) on Derivative, Net	(30,053,000)	54,934,000
TBA Contracts [Member]
Adjustments to reconcile net income (loss) to net cash (used in) provided by operating activities:
Derivative, Gain (Loss) on Derivative, Net	(574,000)	7,090,000
Interest Rate Floor [Member]
Adjustments to reconcile net income (loss) to net cash (used in) provided by operating activities:
Derivative, Gain (Loss) on Derivative, Net	$ (1,384,000)	$ 0