CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) - USD ($) $ in Thousands	Total	Preferred Stock [Member]	Common Stock [Member]	Paid-in Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Beginning Balance at Dec. 31, 2019	$ 1,073,733	$ 250,946	$ 946	$ 1,252,481	$ (444,039)	$ 13,399
Net income (loss)	(181,949)				(181,949)
Change in unrealized gain on mortgage securities, net	65,753					65,753
Amounts related to cash flow hedges, net	(20,400)					(20,400)
Cash dividends:
Common	(29,077)				(29,077)
Preferred	(9,684)				(9,684)
Issuance of common stock	12,857		16	12,841
Other additions to capital	1,656		2	1,654
Ending Balance at Jun. 30, 2020	912,889	250,946	964	1,266,976	(664,749)	58,752
Cash dividends:
Common	(29,077)				(29,077)
Preferred	(9,684)				(9,684)
Beginning Balance at Mar. 31, 2020	843,624	250,946	964	1,266,045	(668,053)	(6,278)
Net income (loss)	22,704				22,704
Change in unrealized gain on mortgage securities, net	64,659					64,659
Amounts related to cash flow hedges, net	371					371
Cash dividends:
Common	(14,558)				(14,558)
Preferred	(4,842)				(4,842)
Other additions to capital	931			931
Ending Balance at Jun. 30, 2020	912,889	250,946	964	1,266,976	(664,749)	58,752
Cash dividends:
Common	(14,558)				(14,558)
Preferred	(4,842)				(4,842)
Beginning Balance at Dec. 31, 2020	910,163	250,946	965	1,268,439	(651,071)	40,884
Net income (loss)	34,471				34,471
Change in unrealized gain on mortgage securities, net	(43,364)					(43,364)
Amounts related to cash flow hedges, net	9,386					9,386
Cash dividends:
Common	(29,122)				(29,122)
Preferred	(9,684)				(9,684)
Other additions to capital	1,163		3	1,160
Ending Balance at Jun. 30, 2021	873,013	250,946	968	1,269,599	(655,406)	6,906
Cash dividends:
Common	(29,122)				(29,122)
Preferred	(9,684)				(9,684)
Beginning Balance at Mar. 31, 2021	903,693	250,946	968	1,269,021	(651,551)	34,309
Net income (loss)	15,529				15,529
Change in unrealized gain on mortgage securities, net	(21,881)					(21,881)
Amounts related to cash flow hedges, net	(5,522)					(5,522)
Cash dividends:
Common	(14,542)				(14,542)
Preferred	(4,842)				(4,842)
Other additions to capital	578			578
Ending Balance at Jun. 30, 2021	873,013	$ 250,946	$ 968	$ 1,269,599	(655,406)	$ 6,906
Cash dividends:
Common	(14,542)				(14,542)
Preferred	$ (4,842)				$ (4,842)