Financing Arrangements - Additional Information (Detail) (USD $)	6 Months Ended
	Jun. 30, 2012	Dec. 31, 2011	Jun. 30, 2011	Dec. 31, 2010
Debt Instrument [Line Items]
Asset-based credit facility, maximum borrowing capacity	$ 230,000,000
Amount outstanding under letters of credit	3,355,000
Asset-based credit facility	70,150,000
Cash and cash equivalents	27,986,000	43,023,000	66,532,000	55,043,000
Asset-based credit facility, maturity date	Jun. 30, 2016
Maximum amount of consolidated funded including borrowing outstanding	170,423,000
Average outstanding borrowing	76,674,000
Description of condition to reduce applicable margin to interest rate	All applicable margins will be permanently reduced by 0.25% if EBITDA, as defined in the ABL Facility, meets or exceeds $25,000,000 over any trailing twelve-month period, and will be permanently reduced by an additional 0.25% if EBITDA meets or exceeds $50,000,000 over any trailing twelve-month period.
Asset-based credit facility, interest rate	4.75%
Borrowing base availability	25,000,000
Asset-based credit facility, origination fees	4,133,000
Unamortized origination fees	3,490,000	3,194,000
Asset-based credit facility, origination fees other current assets	873,000	650,000
Asset-based credit facility, origination fees other long-term assets	2,618,000	2,275,000
UNITED STATES
Debt Instrument [Line Items]
Asset-based credit facility, maximum borrowing capacity	158,333,000
Asset-based credit facility, available for letter of credit	20,000,000
Canada
Debt Instrument [Line Items]
Asset-based credit facility, maximum borrowing capacity	31,667,000
Asset-based credit facility, available for letter of credit	5,000,000
United Kingdom
Debt Instrument [Line Items]
Asset-based credit facility, maximum borrowing capacity	40,000,000
Asset-based credit facility, available for letter of credit	2,000,000
Minimum
Debt Instrument [Line Items]
Asset-based credit facility, monthly fees	0.375%
Maximum
Debt Instrument [Line Items]
Asset-based credit facility, monthly fees	0.50%
Scenario 1
Debt Instrument [Line Items]
Applicable margin rate reduction, (in percent)	0.25%
Scenario 1 | Minimum
Debt Instrument [Line Items]
Amount of EBITDA to reduce applicable margin	25,000,000
Scenario 2
Debt Instrument [Line Items]
Applicable margin rate reduction, (in percent)	0.25%
Scenario 2 | Minimum
Debt Instrument [Line Items]
Amount of EBITDA to reduce applicable margin	$ 50,000,000