Long-Term Debt (Schedule of Long-Term Debt) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2013
Debt Instrument [Line Items]
Less unamortized debt issuance costs	$ 3,768	$ 3,918
Total debt	(209,432)	(209,282)
Less current maturities	400	400
Total long-term debt	209,032	208,882
Senior Subordinated 6.25% Notes
Debt Instrument [Line Items]
Total debt	$ (210,000)	$ (210,000)
Senior Subordinated Notes, interest rate	6.25%	6.25%	6.25%
Other debt
Debt Instrument [Line Items]
Total debt	$ (3,200)	$ (3,200)