Summary of Significant Accounting Policies (Changes in Estimates (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Change in Accounting Estimate [Line Items]
Increase in net income from change in accounting estimate	$ (7,340)	$ (4,895)
Increase in earnings per share from change in accounting estimate	$ (0.30)	$ (0.56)
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