Performance Contingent Total Shareholder Return Shares (Detail) - Total Shareholders Return	6 Months Ended
	Jul. 18, 2015
90th Percentile
Schedule of Share based Compensation Arrangements by Share based Payment Award, Equity Instruments, Other Than Options, Restricted Stock Units [Line Items]
Percentile	90.00%
Payout as % of Target	200.00%
70th Percentile
Schedule of Share based Compensation Arrangements by Share based Payment Award, Equity Instruments, Other Than Options, Restricted Stock Units [Line Items]
Percentile	70.00%
Payout as % of Target	150.00%
50th Percentile
Schedule of Share based Compensation Arrangements by Share based Payment Award, Equity Instruments, Other Than Options, Restricted Stock Units [Line Items]
Percentile	50.00%
Payout as % of Target	100.00%
30th Percentile
Schedule of Share based Compensation Arrangements by Share based Payment Award, Equity Instruments, Other Than Options, Restricted Stock Units [Line Items]
Percentile	30.00%
Payout as % of Target	50.00%
Below 30th Percentile
Schedule of Share based Compensation Arrangements by Share based Payment Award, Equity Instruments, Other Than Options, Restricted Stock Units [Line Items]
Percentile	30.00%
Payout as % of Target	0.00%