Long-Term Debt (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Long-term debt obligation
Total debt	$ 82,687,000	$ 98,000,000
Less current maturities	18,375,000	15,313,000
Total long-term debt	64,312,000	82,687,000
2013 Revolving Credit Facility, due August 16, 2016
Long-term debt obligation
Basis of interest rate	Eurodollar rate
Remaining borrowing capacity	73,800,000	72,500,000
Effective rate of interest (as a percent)	2.42%
2011 Term Loan Facility, due August 16, 2016
Long-term debt obligation
Basis of interest rate	LIBOR
Total debt	$ 82,687,000	$ 98,000,000
Effective rate of interest (as a percent)	2.17%