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	19,420				19,420
Change in unrealized gain on mortgage securities, net	(44,053)					(44,053)
Amounts related to cash flow hedges, net	26,289					26,289
Cash dividends:
Common	(14,742)			(164)	(14,578)
Preferred	(4,842)				(4,842)
Common stock repurchases	(29,062)		(34)	(29,028)
Other additions to capital	342		2	340
Ending Balance at Mar. 31, 2018	1,192,228	250,946	925	1,242,573	(346,570)	44,354
Beginning Balance at Dec. 31, 2018	1,059,063	250,946	853	1,174,880	(346,570)	(21,046)
Net (loss) income	(7,746)				(7,746)
Change in unrealized gain on mortgage securities, net	43,476					43,476
Amounts related to cash flow hedges, net	(19,122)					(19,122)
Cash dividends:
Common	(6,952)				(6,952)
Preferred	(4,842)				(4,842)
Other additions to capital	1,001		3	998
Ending Balance at Mar. 31, 2019	$ 1,064,878	$ 250,946	$ 856	$ 1,175,878	$ (366,110)	$ 3,308