Debt - Narrative (Detail) (USD $)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 24, 2012	Jun. 26, 2011	Jun. 24, 2012	Jun. 26, 2011	Dec. 26, 2010 Contract	Dec. 25, 2011
Debt Instrument [Line Items]
Revolving line of credit	$ 50,000,000		$ 50,000,000			$ 51,500,000
Number of interest rate derivatives held					2
Interest rate swap agreement, expiration date					Jan. 31, 2011
Weighted average interest rate for credit facility borrowings, including the impact of interest rate swaps	1.30%	1.20%	1.30%	2.40%
Interest paid	232,000	248,000	482,000	1,100,000
Interest rate swap liabilities	127,000		127,000
Interest rate swap liability, portion to be reclassified into earnings during the next twelve months	109,000		109,000
Amended Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	175,000,000		175,000,000
Line of credit facility, term	5 years
Interest margin rate on debt, minimum	0.75%		0.75%
Interest margin rate on debt, maximum	1.50%		1.50%
Line of credit facility, remaining borrowing capacity, after reduction for outstanding letters of credit	111,500,000		111,500,000
Line of credit facility initiation date	Nov. 30, 2011
Line of credit facility, maturity date	Nov. 30, 2016
New Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity					175,000,000
Line of credit facility, term					5 years
Interest margin rate on debt, minimum					1.00%
Interest margin rate on debt, maximum					1.75%
Line of credit facility initiation date					Sep. 02, 2010
0.53% Interest Rate Swap Agreement [Member]
Debt Instrument [Line Items]
Derivative, fixed interest rate	0.53%		0.53%
Floating rate debt	50,000,000		50,000,000
Number of interest rate derivatives held	1		1
Interest rate swap agreement, initiation date	Aug. 30, 2011
Interest rate swap agreement, expiration date	Aug. 30, 2013
4.98% Interest Rate Swap Agreement [Member]
Debt Instrument [Line Items]
Derivative, fixed interest rate					4.98%
Floating rate debt					50,000,000
3.74% Interest Rate Swap Agreement [Member]
Debt Instrument [Line Items]
Derivative, fixed interest rate					3.74%
Floating rate debt					50,000,000