Amounts Recognized in Consolidated Balance Sheets (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Mar. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan amounts recognized in balance sheet	$ (35,985)	$ (31,801)
Other assets
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan amounts recognized in balance sheet		260
Accrued expenses
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan amounts recognized in balance sheet	(1,431)	(1,309)
Other liabilities
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan amounts recognized in balance sheet	$ (34,554)	$ (30,752)