Commitments and Contingencies - Additional Information (Detail) - USD ($)			3 Months Ended	12 Months Ended
	Mar. 16, 2015	Sep. 05, 2014	Apr. 30, 2016	Jan. 31, 2015
Commitment And Contingencies [Line Items]
Material off balance sheet commitments			$ 0
Fees and costs awarded to plaintiff's attorney		$ 9,500,000
Litigation accrual				$ 9,500,000
Revised litigation accrual				8,000,000
Loss contingency payment to third party	$ 2,400,000
Merchandise discount coupon rate	33.00%
Merchandise discount coupon expiry period			1 year
Loss contingency, description			On March 16, 2015, the Company, through the third party claims administrator, began mailing the class action award to class members. The Company, through the third party claims administrator, paid approximately $2.4 million in cash awards to the class members and mailed 33% discount coupons, good for one year, on purchases up to $10,000, to class members that did not request the cash award. During a hearing on April 16, 2015, the Court provided additional guidance regarding the manner in which class members can use the 33% merchandise discount coupon. Specifically, the court ordered that the 33% coupons may be combined with the Company’s other promotional offers.
Coupons expiry date			Mar. 16, 2016
Maximum [Member]
Commitment And Contingencies [Line Items]
Merchandise discount coupon, purchases	$ 10,000
Estimated Class Member Response [Member]
Commitment And Contingencies [Line Items]
Decrease in litigation charge				$ (1,500,000)