Income Taxes (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			6 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Income Tax Contingency [Line Items]
Unrecognized tax benefits relating to UTPs	$ 72,000			$ 72,000
Unrecognized tax benefits, interest on income taxes accrued	6,800			6,800
Unrecognized tax benefits, income tax penalties accrued	6,400			6,400
Deferred income tax provision	7,738		$ 1,662	20,812	$ 4,203
Net income (loss)	32,552		$ 17,800	63,238	$ (64,842)
Long-term deferred tax assets	126,194			126,194		$ 152,676
Potential change in unrecognized tax benefits during next twelve months	4,000			4,000
Unrecognized tax benefits that would reduce the income tax provision	30,900			$ 30,900
Restatement Adjustment [Member] | Overstatement [Member]
Income Tax Contingency [Line Items]
Deferred income tax provision		$ 6,900
Net income (loss)	$ 3,200
Earnings per share, basic and diluted	$ 0.10
Restatement Adjustment [Member] | Understatement [Member]
Income Tax Contingency [Line Items]
Net income (loss)		$ 6,900
Earnings per share, basic and diluted		$ 0.22
Long-term deferred tax assets		$ 6,900