Income Taxes (Reconciliation of Federal Statutory Income Tax Rate) (Details) (USD $)
In Thousands, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Income Tax Disclosure [Abstract]      
Tax at statutory rate $ (7,713) $ (38,821) $ (41,291)
State taxes, net of federal benefit (375) (6,399) (4,868)
Change in valuation allowance (640) 216,586 668
Federal and state net operating losses, (addition) removal of limitations (2,882) (173,288) 42,121
Share-based compensation 4,366 2,761 2,597
Credits and other (432) (2,192) 89
Income tax benefit $ (7,676) $ (1,353) $ (684)