Consolidated Statements of Shareholders' Equity Statement - 6 months ended Jun. 30, 2018 - USD ($) $ in Thousands	Total	Preferred Stock	Preferred Stock Including Additional Paid in Capital	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance at Dec. 31, 2017	$ 557,058		$ 141,294	$ 558	$ 775,873	$ (8,697)	$ (351,970)
Balance, Preferred shares outstanding at Dec. 31, 2017	5,888,680	5,888,680
Balance, Common shares outstanding at Dec. 31, 2017	55,831,549			55,831,549
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Issued During Period, Shares, New Issues		20,319		918,629
Stock Issued During Period, Shares, Restricted Stock Award, Gross				213,157
Shares Paid for Tax Withholding for Share Based Compensation				57,135
Stock issuance	$ 6,408		494	$ 10	5,904
Restricted stock granted, net of amortization	629			2	627
Adjustments for tax withholding on share-based compensation	(364)			(1)	(363)
Stock issuance costs	(30)		0		(30)
Net income	59,959						59,959
Dividends on preferred stock	(5,882)						(5,882)
Dividends on common stock	(20,322)						(20,322)
Other comprehensive loss	(55,222)					(55,222)
Balance at Jun. 30, 2018	$ 542,234		$ 141,788	$ 569	$ 782,011	$ (63,919)	$ (318,215)
Balance, Preferred shares outstanding at Jun. 30, 2018	5,908,999	5,908,999
Balance, Common shares outstanding at Jun. 30, 2018	56,906,200			56,906,200