Credit Facilities and Long-Term Debt, Line of Credit (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 250,000	$ 200,000
Expiration date	Mar. 01, 2018
Reduced unused fee (in hundredths)	0.25%
Additional available borrowing capacity	148,900,000
Outstanding borrowings under credit facility	21,406,000	40,453,000
Financial covenants	At any time that our average borrowing availability is less than $25 million, the terms of our restated credit agreement provide for, among other provisions, a financial covenant requiring us, on a consolidated basis, to maintain specified levels of fixed charge coverage at the end of each fiscal quarter (rolling twelve months).
Capital lease obligations	75,000	195,000
Direct Borrowings [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Margin on variable rate (in hundredths)	1.50%
Direct Borrowings [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Margin on variable rate (in hundredths)	2.00%
Index Loan [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Margin on variable rate (in hundredths)	0.50%
Index Loan [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Margin on variable rate (in hundredths)	1.00%
General Electric Capital Corporation Credit Facility [Member]
Line of Credit Facility [Line Items]
Outstanding borrowings under credit facility	21,400,000	40,400,000
Weighted average interest rate (in hundredths)	2.00%	2.70%
General Electric Capital Corporation Credit Facility [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Conditions for required financial covenants, maximum borrowing availability	25,000,000
General Electric Capital Corporation Credit Facility [Member] | Direct Borrowings [Member]
Line of Credit Facility [Line Items]
Outstanding borrowings under credit facility	18,000,000	25,000,000
Weighted average interest rate (in hundredths)	1.70%	2.00%
General Electric Capital Corporation Credit Facility [Member] | Index Loan [Member]
Line of Credit Facility [Line Items]
Outstanding borrowings under credit facility	3,400,000	15,400,000
Weighted average interest rate (in hundredths)	3.80%	4.00%
Average daily loan balance outstanding	4,100,000	6,100,000
GE Canada Finance Holding Company Credit Facility [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	10,000,000
Line of Credit [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 10,000,000