Shareholders' Equity Rollforward (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Schedule of Stockholders' Equity [Line Items]
Preferred Stock, Value, Issued	[1]			$ 0	$ 313,330
Share-based compensation				$ 3,369	$ 2,638
Stock Issued During Period, Shares, Conversion of Convertible Securities				1,458,336	5,924,706
Increase (Decrease) in Stockholders' Equity [Roll Forward]
As of beginning balance				$ 675,817	$ 788,804
Net income (loss)		$ 25,900	$ 89,661	(111,394)	8,102
Dividends Declared	[1]			(12,134)
Dividends Declared					(11,081)
All Other Changes	[2]			2,782	(488)
As of ending balance		555,071	1,098,667	555,071	1,098,667
Preferred stock dividends	[3]	(5,935)	(7,641)	(18,069)	(11,081)
Less: Induced conversion of preferred stock		0	(888)	0	(4,256)
Preferred stock
Schedule of Stockholders' Equity [Line Items]
Preferred Stock, Value, Issued					3,250
Increase (Decrease) in Stockholders' Equity [Roll Forward]
As of beginning balance				4,044	1,150
All Other Changes	[2]			(87)	(356)
As of ending balance		3,957	4,044	3,957	4,044
Common stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
As of beginning balance				529	466
All Other Changes	[2]			19	62
As of ending balance		548	528	548	528
Paid-in capital
Schedule of Stockholders' Equity [Line Items]
Preferred Stock, Value, Issued					310,080
Increase (Decrease) in Stockholders' Equity [Roll Forward]
As of beginning balance				1,206,305	891,351
All Other Changes	[2]			2,882	3,871
As of ending balance		1,209,187	1,205,302	1,209,187	1,205,302
Accumulated deficit
Increase (Decrease) in Stockholders' Equity [Roll Forward]
As of beginning balance				(535,176)	(104,180)
Net income (loss)				(111,394)
All Other Changes	[2]				(4,256)
As of ending balance		(658,704)	(111,415)	(658,704)	(111,415)
Preferred stock dividends	[1]			(12,134)	(11,081)
Deferred compensation obligation
Increase (Decrease) in Stockholders' Equity [Roll Forward]
As of beginning balance				3,211	2,792
All Other Changes	[2]			229	314
As of ending balance		3,440	3,106	3,440	3,106
Accumulated other comprehensive income
Increase (Decrease) in Stockholders' Equity [Roll Forward]
As of beginning balance	[4]			249	267
All Other Changes	[4]			(32)	74
As of ending balance	[4]	217	341	217	341
Treasury stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
As of beginning balance				(3,345)	(3,042)
All Other Changes	[2]			(229)	(197)
As of ending balance		$ (3,574)	$ (3,239)	$ (3,574)	(3,239)
Series A Preferred Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Less: Induced conversion of preferred stock					$ (4,300)
Convertible Preferred Stock
Schedule of Stockholders' Equity [Line Items]
Conversion of Stock, Shares Converted				875	3,555

[1] Includes dividends declared of $300.00 per share and $450.00 per share of our Series A 6% Convertible Perpetual Preferred Stock (the “Series A Preferred Stock”) during the nine months ended September 30, 2015 and 2014, respectively, and $300.00 per share and $198.33 per share of our Series B 6% Convertible Perpetual Preferred Stock (the “Series B Preferred Stock”) for the nine months ended September 30, 2015 and 2014, respectively.

[2] Includes equity-classified share-based compensation of $3,369 and $2,638 for the nine months ended September 30, 2015 and 2014, respectively.

[3] Preferred stock dividends and payments to induce the conversion of preferred stock were excluded from the computation of diluted earnings per share for the nine months ended September 30, 2015 and 2014 as the assumed conversion of the outstanding preferred stock would have been anti-dilutive.

[4] Accumulated other comprehensive income (“AOCI”) is entirely attributable to our defined benefit pension and postretirement health care plans. The changes in the balance of AOCI for the nine months ended September 30, 2015 and 2014 represent reclassifications from AOCI to net periodic benefit expense, a component of General and administrative expenses, of $(49) and $114 and are presented above net of taxes of $(17) and $40, respectively.