Consolidated Statements of Shareholders' Equity Statement - USD ($) $ in Thousands	Total	Preferred Stock	Common Stock	Preferred Stock Including Additional Paid in Capital	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance, Preferred shares outstanding at Dec. 31, 2017		5,888,680
Balance, Common shares outstanding at Dec. 31, 2017			55,831,549
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Issued During Period, Shares, New Issues		20,319	45,401
Stock Issued During Period, Shares, Restricted Stock Award, Gross			176,233
Shares Paid for Tax Withholding for Share Based Compensation			57,135
Balance, Preferred shares outstanding at Mar. 31, 2018		5,908,999
Balance, Common shares outstanding at Mar. 31, 2018			55,996,048
Balance at Dec. 31, 2017	$ 557,058		$ 558	$ 141,294	$ 775,873	$ (8,697)	$ (351,970)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance	788		1	494	293
Restricted stock granted, net of amortization	335		2		333
Adjustments for tax withholding on share-based compensation	(364)		(1)		(363)
Stock issuance costs	(19)			0	(19)
Net income (loss)	44,307						44,307
Dividends on preferred stock	(2,940)						(2,940)
Dividends on common stock	(10,079)						(10,079)
Other comprehensive income (loss)	(45,462)					(45,462)
Balance at Mar. 31, 2018	$ 543,624		$ 560	141,788	776,117	(54,159)	(320,682)
Balance, Preferred shares outstanding at Dec. 31, 2018	5,954,594	5,954,594
Balance, Common shares outstanding at Dec. 31, 2018	62,817,218		62,817,218
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Issued During Period, Shares, New Issues		213,468	9,327,139
Stock Issued During Period, Shares, Restricted Stock Award, Gross			152,462
Shares Paid for Tax Withholding for Share Based Compensation			48,693
Balance, Preferred shares outstanding at Mar. 31, 2019	6,168,062	6,168,062
Balance, Common shares outstanding at Mar. 31, 2019	72,248,126		72,248,126
Balance at Dec. 31, 2018	$ 527,153		$ 628	142,883	818,442	(35,779)	(399,021)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance	58,887		93	5,015	53,779
Restricted stock granted, net of amortization	298		2		296
Adjustments for tax withholding on share-based compensation	(296)		(1)		(295)
Stock issuance costs	(212)			0	(212)
Net income (loss)	(52,214)						(52,214)
Dividends on preferred stock	(3,059)						(3,059)
Dividends on common stock	(12,350)						(12,350)
Other comprehensive income (loss)	86,467					86,467
Balance at Mar. 31, 2019	$ 604,674		$ 722	$ 147,898	$ 872,010	$ 50,688	$ (466,644)