Debt New Revolving Credit Agreement (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Debt Instrument [Line Items]
Interest income from investment of excess cash balances	$ 222	$ 254	$ 201
New Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Senior secured asset-based revolving credit facility		100,000
Aggregate principal amount available for a Canadian subfacility	20,000
Aggregate principal amount available for letters of credit	20,000
Aggregate principal amount available for swingline loans	10,000
Maturity date	Dec. 15, 2015
Weighted average interest rate for borrowings	2.71%	1.63%
Provision to increase aggregate amount of commitments under certain conditions, amount	50,000
Ratio of EBITDA to fixed charges	1.1
Excess availability	50,543
Minimum | New Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Customary base rate plus an applicable margin percentage	0.50%
Adjusted LIBOR rate plus an applicable margin	1.50%
Percentage of maximum calculated borrowing base to fixed charge of EBITDA	10.00%
Calculated borrowing base	10,000
Maximum | New Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Customary base rate plus an applicable margin percentage	1.00%
Adjusted LIBOR rate plus an applicable margin	2.00%
Percentage of maximum calculated borrowing base to fixed charge of EBITDA	12.50%
Calculated borrowing base	$ 12,500