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			18,610,516
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Issued During Period, Shares, New Issues		20,319	15,133
Stock Issued During Period, Shares, Restricted Stock Award, Gross			58,745
Shares Paid for Tax Withholding for Share Based Compensation			19,045
Balance, Preferred shares outstanding at Mar. 31, 2018		5,908,999
Balance, Common shares outstanding at Mar. 31, 2018			18,665,349
Balance at Dec. 31, 2017	$ 557,058		$ 186	$ 141,294	$ 776,245	$ (8,697)	$ (351,970)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance	788		0	494	294
Restricted stock granted, net of amortization	335		1		334
Adjustments for tax withholding on share-based compensation	(364)		0		(364)
Stock issuance costs	(19)				(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		$ 187	141,788	776,490	(54,159)	(320,682)
Balance, Preferred shares outstanding at Dec. 31, 2017		5,888,680
Balance, Common shares outstanding at Dec. 31, 2017			18,610,516
Balance, Preferred shares outstanding at Jun. 30, 2018		5,908,999
Balance, Common shares outstanding at Jun. 30, 2018			18,968,733
Balance at Dec. 31, 2017	557,058		$ 186	141,294	776,245	(8,697)	(351,970)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	59,959
Other comprehensive income (loss)	(55,222)
Balance at Jun. 30, 2018	542,234		$ 190	141,788	782,390	(63,919)	(318,215)
Balance, Preferred shares outstanding at Mar. 31, 2018		5,908,999
Balance, Common shares outstanding at Mar. 31, 2018			18,665,349
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Issued During Period, Shares, New Issues		0	291,076
Stock Issued During Period, Shares, Restricted Stock Award, Gross			12,308
Balance, Preferred shares outstanding at Jun. 30, 2018		5,908,999
Balance, Common shares outstanding at Jun. 30, 2018			18,968,733
Balance at Mar. 31, 2018	543,624		$ 187	141,788	776,490	(54,159)	(320,682)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance	5,620		3	0	5,617
Restricted stock granted, net of amortization	294		0		294
Stock issuance costs	(11)				(11)
Net income (loss)	15,652						15,652
Dividends on preferred stock	(2,942)						(2,942)
Dividends on common stock	(10,243)						(10,243)
Other comprehensive income (loss)	(9,760)					(9,760)
Balance at Jun. 30, 2018	$ 542,234		$ 190	141,788	782,390	(63,919)	(318,215)
Balance, Preferred shares outstanding at Dec. 31, 2018	5,954,594	5,954,594
Balance, Common shares outstanding at Dec. 31, 2018	20,939,072		20,939,073
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Issued During Period, Shares, New Issues		213,468	3,109,047
Stock Issued During Period, Shares, Restricted Stock Award, Gross			50,821
Shares Paid for Tax Withholding for Share Based Compensation			16,231
Balance, Preferred shares outstanding at Mar. 31, 2019		6,168,062
Balance, Common shares outstanding at Mar. 31, 2019			24,082,710
Balance at Dec. 31, 2018	$ 527,153		$ 209	142,883	818,861	(35,779)	(399,021)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance	58,887		31	5,015	53,841
Restricted stock granted, net of amortization	298		1		297
Adjustments for tax withholding on share-based compensation	(296)		0		(296)
Stock issuance costs	(212)				(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		$ 241	147,898	872,491	50,688	(466,644)
Balance, Preferred shares outstanding at Dec. 31, 2018	5,954,594	5,954,594
Balance, Common shares outstanding at Dec. 31, 2018	20,939,072		20,939,073
Balance, Preferred shares outstanding at Jun. 30, 2019	6,514,130	6,514,130
Balance, Common shares outstanding at Jun. 30, 2019	24,646,964		24,646,964
Balance at Dec. 31, 2018	$ 527,153		$ 209	142,883	818,861	(35,779)	(399,021)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(171,199)
Other comprehensive income (loss)	197,594
Balance at Jun. 30, 2019	$ 598,638		$ 246	156,071	882,633	161,815	(602,127)
Balance, Preferred shares outstanding at Mar. 31, 2019		6,168,062
Balance, Common shares outstanding at Mar. 31, 2019			24,082,710
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock Issued During Period, Shares, New Issues		346,068	547,071
Stock Issued During Period, Shares, Restricted Stock Award, Gross			17,183
Balance, Preferred shares outstanding at Jun. 30, 2019	6,514,130	6,514,130
Balance, Common shares outstanding at Jun. 30, 2019	24,646,964		24,646,964
Balance at Mar. 31, 2019	$ 604,674		$ 241	147,898	872,491	50,688	(466,644)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance	18,052		5	8,173	9,874
Restricted stock granted, net of amortization	296		0		296
Stock issuance costs	(28)				(28)
Net income (loss)	(118,985)						(118,985)
Dividends on preferred stock	(3,206)						3,206
Dividends on common stock	(13,292)						(13,292)
Other comprehensive income (loss)	111,127					111,127
Balance at Jun. 30, 2019	$ 598,638		$ 246	$ 156,071	$ 882,633	$ 161,815	$ (602,127)