Goodwill and Other Intangible Assets - Carrying Amount and Accumulated Amortization of Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	May. 31, 2015	Feb. 28, 2015
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life (in years)	9 years 3 months 18 days	9 years 6 months
Gross Carrying Amount	$ 76,752	$ 76,752
Accumulated Amortization	30,608	29,116
Amortized intangible assets, Net	$ 46,144	$ 47,636
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life (in years)
Gross Carrying Amount	$ 1,234	$ 1,234
Accumulated Amortization	1,234	1,234
Amortized intangible assets, Net	$ 0	$ 0
Customer Lists [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life (in years)	9 years 3 months 18 days	9 years 7 months 6 days
Gross Carrying Amount	$ 74,670	$ 74,670
Accumulated Amortization	28,940	27,486
Amortized intangible assets, Net	$ 45,730	$ 47,184
Noncompete [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life (in years)	2 years 7 months 6 days	2 years 9 months 18 days
Gross Carrying Amount	$ 75	$ 75
Accumulated Amortization	10	4
Amortized intangible assets, Net	$ 65	$ 71
Patent [Member]
Finite-Lived Intangible Assets [Line Items]
Weighted Average Remaining Life (in years)	2 years 9 months 18 days	3 years
Gross Carrying Amount	$ 773	$ 773
Accumulated Amortization	424	392
Amortized intangible assets, Net	$ 349	$ 381