Schedule of Other Assets (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Mar. 31, 2016
Other Assets, Noncurrent [Abstract]
Recoverable insurance losses	$ 11,144	$ 9,412
Deferred income tax assets	46,868	33,505
Savings plans and supplemental plan	14,546	14,472
Other	17,409	14,297
Total other assets	$ 89,967	$ 71,686