Long-Term Debt (Schedule of Long-Term Debt) (Details) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015	Mar. 31, 2013
Debt Instrument [Line Items]
Less unamortized debt issuance costs	$ (3,564)	$ (3,918)
Total debt	(209,236)	(209,282)
Less current maturities	400	400
Total long-term debt	208,836	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	$ (2,800)	$ (3,200)