Weighted Average Amortization Period, by Intangible Asset Class (Detail)	Mar. 31, 2012 Year
Acquired Finite-Lived Intangible Assets [Line Items]
Wighted Average Amortization Period	7.2
Trademarks and patents
Acquired Finite-Lived Intangible Assets [Line Items]
Wighted Average Amortization Period	8.9
Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Wighted Average Amortization Period	6.0
Covenant not-to-compete
Acquired Finite-Lived Intangible Assets [Line Items]
Wighted Average Amortization Period	3.6
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Wighted Average Amortization Period	9.3