Summary of Significant Accounting Policies (Changes in Estimates (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Change in Accounting Estimate [Line Items]
Increase in net income from change in accounting estimate	$ (6,068)	$ (20,363)	$ (13,408)	$ (25,258)
Increase in earnings per share from change in accounting estimate	$ (0.24)	$ (2.31)	$ (0.54)	$ (3.09)
Bonus Expense [Member]
Change in Accounting Estimate [Line Items]
Increase in net income from change in accounting estimate	$ 375
Increase in earnings per share from change in accounting estimate	$ 0.02