Debt - Additional Information (Detail) (USD $)	1 Months Ended	6 Months Ended
	Nov. 10, 2010	Jul. 28, 2012
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	$ 75,000,000
Line of credit facility, potential maximum borrowing capacity	125,000,000
Line of credit facility, expiration date	Nov. 10, 2014
Line of credit facility, interest rate description	Borrowings made pursuant to the Credit Facility will bear interest at a rate equal to the base rate (determined as the highest of (a) Bank of America N.A.’s prime rate, (b) the Federal Funds rate plus 0.50% and (c) the one month LIBOR rate) plus a varying percentage, based on the Company’s borrowing base, of 1.00-1.25% for prime-based borrowings and 2.00-2.25% for LIBOR-based borrowings.
Line of credit facility, interest rate at period end		4.25%
Line of credit facility, remaining borrowing capacity		69,500,000
Line of credit facility, average outstanding amount		160,000
Line of credit facility, average unused excess availability		69,500,000
Federal Funds Rate
Line of Credit Facility [Line Items]
Line of credit facility, basis spread on variable rate	0.50%
Prime Rate | Minimum
Line of Credit Facility [Line Items]
Line of credit facility, basis spread on variable rate	1.00%
Prime Rate | Maximum
Line of Credit Facility [Line Items]
Line of credit facility, basis spread on variable rate	1.25%
LIBOR | Minimum
Line of Credit Facility [Line Items]
Line of credit facility, basis spread on variable rate	2.00%
LIBOR | Maximum
Line of Credit Facility [Line Items]
Line of credit facility, basis spread on variable rate	2.25%
Commercial and Standby Letters of Credit
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	20,000,000
Swingline Loans
Line of Credit Facility [Line Items]
Line of credit facility, maximum borrowing capacity	15,000,000
Standby Letters of Credit
Line of Credit Facility [Line Items]
Letters of credit outstanding, amount		2,300,000
Documentary Letters of Credit
Line of Credit Facility [Line Items]
Letters of credit outstanding, amount		$ 3,200,000