Consolidated Statements of Shareholders' Equity Statement - USD ($)	Total	Preferred Stock	Preferred Stock Including Additional Paid in Capital	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Balance, Preferred shares outstanding at Dec. 31, 2018		5,954,594
Balance, Common shares outstanding at Dec. 31, 2018				20,939,073
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance, shares		213,468		3,109,047
Restricted stock granted, net of amortization				50,821
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation				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	$ 527,153,000		$ 142,883,000	$ 209,000	$ 818,861,000	$ (35,779,000)	$ (399,021,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance, value	58,887,000		5,015,000	31,000	53,841,000
Restricted stock granted, net of amortization	298,000			1,000	297,000
Adjustments for tax withholding on share-based compensation	(296,000)			0	(296,000)
Stock issuance costs	(212,000)				(212,000)
Net income (loss)	(52,214,000)						(52,214,000)
Dividends on preferred stock	(3,059,000)						(3,059,000)
Dividends on common stock	(12,350,000)						(12,350,000)
Other Comprehensive Income (Loss), Net of Tax	86,467,000					86,467,000
Balance at Mar. 31, 2019	604,674,000		147,898,000	$ 241,000	872,491,000	50,688,000	(466,644,000)
Balance, Preferred shares outstanding at Dec. 31, 2018		5,954,594
Balance, Common shares outstanding at Dec. 31, 2018				20,939,073
Balance, Preferred shares outstanding at Sep. 30, 2019		6,788,330
Balance, Common shares outstanding at Sep. 30, 2019				22,945,993
Balance at Dec. 31, 2018	527,153,000		142,883,000	$ 209,000	818,861,000	(35,779,000)	(399,021,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(207,803,000)
Other Comprehensive Income (Loss), Net of Tax	252,789,000
Balance at Sep. 30, 2019	584,447,000		162,807,000	$ 229,000	858,050,000	217,010,000	(653,649,000)
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 issuance, shares		346,068		547,071
Restricted stock granted, net of amortization				17,183
Balance, Preferred shares outstanding at Jun. 30, 2019		6,514,130
Balance, Common shares outstanding at Jun. 30, 2019				24,646,964
Balance at Mar. 31, 2019	604,674,000		147,898,000	$ 241,000	872,491,000	50,688,000	(466,644,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance, value	18,052,000		8,173,000	5,000	9,874,000
Restricted stock granted, net of amortization	296,000			0	296,000
Stock issuance costs	(28,000)				(28,000)
Net income (loss)	(118,985,000)						(118,985,000)
Dividends on preferred stock	(3,206,000)						(3,206,000)
Dividends on common stock	(13,292,000)						(13,292,000)
Other Comprehensive Income (Loss), Net of Tax	111,127,000					111,127,000
Balance at Jun. 30, 2019	598,638,000		156,071,000	$ 246,000	882,633,000	161,815,000	(602,127,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance, shares		274,200		8,300
Restricted stock granted, net of amortization				0
Stock Repurchased During Period, Shares				(1,709,271)
Balance, Preferred shares outstanding at Sep. 30, 2019		6,788,330
Balance, Common shares outstanding at Sep. 30, 2019				22,945,993
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance, value	6,873,000		6,736,000	$ 0	137,000
Restricted stock granted, net of amortization	306,000			0	306,000
Stock Repurchased During Period, Value	(25,034,000)			17,000	(25,017,000)
Stock issuance costs	(9,000)				(9,000)
Net income (loss)	(36,604,000)						(36,604,000)
Dividends on preferred stock	(3,341,000)						(3,341,000)
Dividends on common stock	(11,577,000)						(11,577,000)
Other Comprehensive Income (Loss), Net of Tax	55,195,000					55,195,000
Balance at Sep. 30, 2019	$ 584,447,000		162,807,000	$ 229,000	858,050,000	217,010,000	(653,649,000)
Balance, Preferred shares outstanding at Dec. 31, 2019	6,788,330	6,788,330
Balance, Common shares outstanding at Dec. 31, 2019	22,945,993			22,945,993
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance, shares		4,460,000
Stock Redeemed or Called During Period, Shares		4,000,000
Restricted stock granted, net of amortization				67,511
Stock Repurchased During Period, Shares				(18,782)
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation				(12,744)
Balance, Preferred shares outstanding at Mar. 31, 2020		7,248,330
Balance, Common shares outstanding at Mar. 31, 2020				22,981,978
Balance at Dec. 31, 2019	$ 582,988,000		162,807,000	$ 229,000	858,347,000	173,806,000	(612,201,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance, value	107,988,000		107,988,000
Stock Redeemed or Called During Period, Value	100,000,000		96,086,000				3,914,000
Restricted stock granted, net of amortization	307,000			1,000	306,000
Stock Repurchased During Period, Value	(206,000)			0	(206,000)
Adjustments for tax withholding on share-based compensation	(235,000)			0	(235,000)
Stock issuance costs	(9,000)				(9,000)
Net income (loss)	(98,479,000)						98,479,000
Dividends on preferred stock	(3,841,000)						(3,841,000)
Dividends on common stock	(10,330,000)						(10,330,000)
Other Comprehensive Income (Loss), Net of Tax	72,972,000					72,972,000
Balance at Mar. 31, 2020	$ 550,607,000		174,709,000	$ 230,000	858,203,000	246,778,000	(729,313,000)
Balance, Preferred shares outstanding at Dec. 31, 2019	6,788,330	6,788,330
Balance, Common shares outstanding at Dec. 31, 2019	22,945,993			22,945,993
Balance, Preferred shares outstanding at Sep. 30, 2020	7,248,330	7,248,330
Balance, Common shares outstanding at Sep. 30, 2020	23,145,238			23,145,238
Balance at Dec. 31, 2019	$ 582,988,000		162,807,000	$ 229,000	858,347,000	173,806,000	(612,201,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	137,084,000
Other Comprehensive Income (Loss), Net of Tax	(85,077,000)
Balance at Sep. 30, 2020	603,553,000		174,709,000	$ 231,000	859,089,000	88,729,000	(519,205,000)
Balance, Preferred shares outstanding at Mar. 31, 2020		7,248,330
Balance, Common shares outstanding at Mar. 31, 2020				22,981,978
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock granted, net of amortization				172,782
Stock Repurchased During Period, Shares				(14,143)
Balance, Preferred shares outstanding at Jun. 30, 2020		7,248,330
Balance, Common shares outstanding at Jun. 30, 2020				23,140,617
Balance at Mar. 31, 2020	550,607,000		174,709,000	$ 230,000	858,203,000	246,778,000	(729,313,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Restricted stock granted, net of amortization	423,000			1,000	422,000
Stock Repurchased During Period, Value	(166,000)				(166,000)
Stock issuance costs	(8,000)				(8,000)
Net income (loss)	194,838,000						(194,838,000)
Dividends on preferred stock	(3,253,000)						(3,253,000)
Dividends on common stock	(9,925,000)						(9,925,000)
Other Comprehensive Income (Loss), Net of Tax	(165,047,000)					(165,047,000)
Balance at Jun. 30, 2020	$ 567,469,000		174,709,000	$ 231,000	858,451,000	81,731,000	(547,653,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance, shares				5,219
Share-based Payment Arrangement, Shares Withheld for Tax Withholding Obligation				598
Balance, Preferred shares outstanding at Sep. 30, 2020	7,248,330	7,248,330
Balance, Common shares outstanding at Sep. 30, 2020	23,145,238			23,145,238
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issuance, value	$ 85,000			$ 0	85,000
Restricted stock granted, net of amortization	568,000				568,000
Adjustments for tax withholding on share-based compensation	(10,000)				10,000
Stock issuance costs	(5,000)				5,000
Net income (loss)	40,725,000						(40,725,000)
Dividends on preferred stock	(3,252,000)						(3,252,000)
Dividends on common stock	(9,025,000)						(9,025,000)
Other Comprehensive Income (Loss), Net of Tax	6,998,000					6,998,000
Balance at Sep. 30, 2020	$ 603,553,000		$ 174,709,000	$ 231,000	$ 859,089,000	$ 88,729,000	$ (519,205,000)