Deferred Stock Activity (Detail) (Deferred Stock Activity, USD $) In Thousands, except Share data, unless otherwise specified	4 Months Ended
	Apr. 20, 2013 Y
Deferred Stock Activity
Number of Shares
Number of Shares, Balance at beginning of period	252,000
Number of shares, Deferred stock issued	24,000
Number of shares, Deferred stock exercised	(24,000)
Number of shares, Balance at end of period	252,000
Outstanding vested at end of period	160,000
Outstanding unvested at end of period	92,000
Shares vesting at end of period	24,000
Weighted Average Fair Value
Weighted Average Fair Value, at beginning of period	$ 17.24
Weighted Average Fair Value, Deferred stock issued	$ 21.60
Weighted Average Fair Value, Deferred stock exercised	$ 16.22
Weighted Average Fair Value, Balance at end of period	$ 17.76
Outstanding vested at end of period	$ 15.98
Outstanding unvested at end of period	$ 20.86
Shares vesting at end of period	$ 16.22
Outstanding vested at end of period, Weighted Average Remaining Contractual Term (Years)
Outstanding unvested at end of period, Weighted Average Remaining Contractual Term (Years)
Aggregate Intrinsic Value, Balance at end of period	$ 8,121
Outstanding vested at end of period, Aggregate Intrinsic Value	5,167
Outstanding unvested at end of period, Aggregate Intrinsic Value	2,954
Shares vesting at end of period, Aggregate Intrinsic Value	$ 776