Subsequent Events - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Jan. 31, 2014	Mar. 03, 2014
Subsequent Event [Member]
Subsequent Event [Line Items]
Agreement extension period	10 years
Minimum order commitment obligation		$ 500.0
March 1, 2014 to September 1, 2020 [Member]
Subsequent Event [Line Items]
Minimum order commitment obligation	250.0
September 1, 2025 [Member]
Subsequent Event [Line Items]
Minimum order commitment obligation	$ 500.0