Long-Term Debt (Schedule of Long-Term Debt) (Details) - USD ($)	Jun. 30, 2015	Dec. 31, 2014	Mar. 31, 2013
Debt Instrument [Line Items]
Total debt	$ 243,200,000	$ 213,600,000
Less current maturities	400,000	400,000
Total long-term debt	242,800,000	213,200,000
Senior Subordinated 6.25% Notes
Debt Instrument [Line Items]
Total debt	$ 210,000,000	210,000,000
Senior Subordinated Notes, interest rate	6.25%		6.25%
Revolving credit facility
Debt Instrument [Line Items]
Total debt	$ 30,000,000	0
Other debt
Debt Instrument [Line Items]
Total debt	$ 3,200,000	$ 3,600,000