Credit Facilities and Long-Term Debt (Details) (USD $)	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Debt Instrument [Line Items]
Revolving credit facilities	$ 75,553,000		$ 40,453,000
Other	163,000		195,000
Total debt	75,716,000		40,648,000
Current maturities of debt	75,675,000		40,573,000
Long-term debt	41,000		75,000
Deferred Financing Costs [Abstract]
Deferred financing costs	2,300,000		2,600,000
Amortization of financing costs in 2013	900,000
Amortization of financing costs in 2014	1,200,000
Amortization of financing costs in 2015	200,000
Line of Credit Facility [Line Items]
Maximum borrowing capacity	200,000,000
Expiration date	Mar. 01, 2015
Additional available borrowing capacity	115,800,000
Outstanding borrowings under credit facility	75,553,000		40,453,000
Financial covenants	At any time that our average borrowing availability over the previous thirty days is less than $30 million or if our borrowing availability is $20 million or less, and until such time that we have maintained an average borrowing availability of $30 million or greater for a continuous period of ninety days, the terms of our restated credit agreement provide for, among other provisions, financial covenants requiring us, on a consolidated basis, (1) to maintain specified levels of fixed charge coverage at the end of each fiscal quarter (rolling twelve months), and (2) to limit capital expenditure levels.
Capital lease obligations	163,000		195,000
Direct Borrowings [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Margin on variable rate (in hundredths)	1.75%
Direct Borrowings [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Margin on variable rate (in hundredths)	2.25%
Index Loan [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Margin on variable rate (in hundredths)	0.75%
Index Loan [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Margin on variable rate (in hundredths)	1.25%
General Electric Capital Corporation Credit Facility [Member]
Debt Instrument [Line Items]
Revolving credit facilities	75,500,000		40,400,000
Line of Credit Facility [Line Items]
Outstanding borrowings under credit facility	75,500,000		40,400,000
Weighted average interest rate (in hundredths)	2.10%		2.70%
General Electric Capital Corporation Credit Facility [Member] | Minimum [Member]
Line of Credit Facility [Line Items]
Conditions for required financial covenants, minimum average borrowing availability over previous 30 days	30,000,000
Conditions for required financial covenants, minimum average borrowing availability over continuous 90 Days	30,000,000
General Electric Capital Corporation Credit Facility [Member] | Maximum [Member]
Line of Credit Facility [Line Items]
Conditions for required financial covenants, maximum borrowing availability	20,000,000
General Electric Capital Corporation Credit Facility [Member] | Direct Borrowings [Member]
Debt Instrument [Line Items]
Revolving credit facilities	69,000,000		25,000,000
Line of Credit Facility [Line Items]
Outstanding borrowings under credit facility	69,000,000		25,000,000
Weighted average interest rate (in hundredths)	2.00%		2.00%
General Electric Capital Corporation Credit Facility [Member] | Index Loan [Member]
Debt Instrument [Line Items]
Revolving credit facilities	6,500,000		15,400,000
Line of Credit Facility [Line Items]
Outstanding borrowings under credit facility	6,500,000		15,400,000
Weighted average interest rate (in hundredths)	4.00%		4.00%
Average daily loan balance outstanding	5,700,000	5,000,000	6,100,000
GE Canada Finance Holding Company Credit Facility [Member]
Debt Instrument [Line Items]
Revolving credit facilities	0
Line of Credit Facility [Line Items]
Maximum borrowing capacity	10,000,000
Outstanding borrowings under credit facility	0
Line of Credit [Member]
Line of Credit Facility [Line Items]
Maximum borrowing capacity	$ 10,000,000