Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Income Taxes [Abstract]
Gross Deferred Income Tax Expense (Benefit)	$ 3,600	$ 53,200	$ 16,800	$ 132,500
Deferred Income Tax Expense (Benefit)			332	$ (132,462)
Deferred income tax assets [Abstract]
Valuation allowance	138,800		138,800		$ 121,600
Valuation Allowance, Deferred Tax Asset, Change in Amount	$ 3,000		$ 17,200
Income Tax Examination [Line Items]
Effective Income Tax Rate Reconciliation, Percent, Total	(0.30%)	38.30%	(2.20%)	37.80%
Internal Revenue Service (IRS) [Member] | Minimum [Member]
Income Tax Examination [Line Items]
Tax years open for future examination			2012
Internal Revenue Service (IRS) [Member] | Maximum [Member]
Income Tax Examination [Line Items]
Tax years open for future examination			2014