Retirement Plans - Amounts Recognized in Consolidated Balance Sheets (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Mar. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan amounts recognized in balance sheet	$ (46,061)	$ (44,106)
Noncurrent assets
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan amounts recognized in balance sheet	0	46
Accrued expenses
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan amounts recognized in balance sheet	(1,657)	(1,222)
Other liabilities
Defined Benefit Plan Disclosure [Line Items]
Defined benefit plan amounts recognized in balance sheet	$ (44,404)	$ (42,930)