Notes Payable and Long-Term Debt - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 Ratio
Line of Credit Facility [Line Items]
Revolving credit facility borrowings	$ 70
Debt maturity date	Aug. 17, 2015
Average interest rate	2.80%
Letters of credit facility outstanding	4.6
Minimum fixed charge coverage ratio	1.0
Fixed charge coverage ratio	1.2
Revolving Credit Facilities [Member]
Line of Credit Facility [Line Items]
Average interest rate	2.80%
Maximum [Member]
Line of Credit Facility [Line Items]
Excess availability under Wells Fargo facility maximum	30.2
Maximum [Member] | Prime [Member]
Line of Credit Facility [Line Items]
Margin interest rate	0.50%
Maximum [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Margin interest rate	2.25%
Minimum [Member]
Line of Credit Facility [Line Items]
Excess availability under Wells Fargo facility maximum	$ 10.0
Minimum [Member] | Prime [Member]
Line of Credit Facility [Line Items]
Margin interest rate	0.25%
Minimum [Member] | LIBOR [Member]
Line of Credit Facility [Line Items]
Margin interest rate	2.00%