Derivative Instruments And Hedging Activities - Additional Information (Detail) € in Millions, $ in Millions	Sep. 30, 2015 EUR (€)	Sep. 30, 2015 USD ($)	Mar. 31, 2015	Sep. 30, 2014 USD ($)
2010 Senior Notes [Member]
Derivative [Line Items]
Derivative Notional Amount				$ 250.0
2014 Senior Notes (5-Year) [Member]
Derivative [Line Items]
Derivative Notional Amount		$ 200.0		$ 250.0
Cross-Currency Swap [Member] | Currency Paid [Member]
Derivative [Line Items]
Derivative Notional Amount | €	€ 100
Derivative Fixed Interest Rate			1.75%
Cross-Currency Swap [Member] | Currency Received [Member]
Derivative [Line Items]
Derivative Notional Amount		$ 110.5
Derivative Fixed Interest Rate			3.945%
2015 Senior Notes [Member]
Derivative [Line Items]
Derivative Notional Amount | €	€ 400