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, 2017	$ 1,238,876	$ 250,946	$ 957	$ 1,271,425	$ (346,570)	$ 62,118
Net (loss) income	32,408				32,408
Change in unrealized gain on mortgage securities, net	(60,565)					(60,565)
Amounts related to cash flow hedges, net	24,191					24,191
Cash dividends:
Common	(27,664)			(4,940)	(22,724)
Preferred	(9,684)				(9,684)
Common stock repurchases	(29,473)		(35)	(29,438)
Other additions to capital	767		2	765
Ending Balance at Jun. 30, 2018	1,168,856	250,946	924	1,237,812	(346,570)	25,744
Beginning Balance at Mar. 31, 2018	1,192,228	250,946	925	1,242,573	(346,570)	44,354
Net (loss) income	12,988				12,988
Change in unrealized gain on mortgage securities, net	(16,512)					(16,512)
Amounts related to cash flow hedges, net	(2,098)					(2,098)
Cash dividends:
Common	(12,922)			(4,776)	(8,146)
Preferred	(4,842)				(4,842)
Common stock repurchases	(411)		(1)	(410)
Other additions to capital	425			425
Ending Balance at Jun. 30, 2018	1,168,856	250,946	924	1,237,812	(346,570)	25,744
Beginning Balance at Dec. 31, 2018	1,059,063	250,946	853	1,174,880	(346,570)	(21,046)
Net (loss) income	(71,206)				(71,206)
Change in unrealized gain on mortgage securities, net	92,026					92,026
Amounts related to cash flow hedges, net	(32,219)					(32,219)
Cash dividends:
Common	(17,243)				(17,243)
Preferred	(9,684)				(9,684)
Other additions to capital	1,651		2	1,649
Ending Balance at Jun. 30, 2019	1,022,388	250,946	855	1,176,529	(444,703)	38,761
Beginning Balance at Mar. 31, 2019	1,064,878	250,946	856	1,175,878	(366,110)	3,308
Net (loss) income	(63,460)				(63,460)
Change in unrealized gain on mortgage securities, net	48,550					48,550
Amounts related to cash flow hedges, net	(13,097)					(13,097)
Cash dividends:
Common	(10,291)				(10,291)
Preferred	(4,842)				(4,842)
Other additions to capital	650		(1)	651
Ending Balance at Jun. 30, 2019	$ 1,022,388	$ 250,946	$ 855	$ 1,176,529	$ (444,703)	$ 38,761