Property, Plant and Equipment - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Feb. 28, 2014	Feb. 28, 2013	Feb. 29, 2012
Property Plant And Equipment [Abstract]
Property, plant and equipment disposed	$ 27,000	$ 36,000
Accumulated depreciation of disposed property, plant and equipment	24,000	34,000
Depreciation expense	50,751	44,326	38,651
Interest expense capitalized	$ 3,748	$ 2,355	$ 1,138