Summary of Allowance for Doubtful Accounts Receivable (Detail) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Receivables [Abstract]
Balance at Beginning of Period	$ 124	$ 177	$ 185
Additions	159	42	115
Write-offs	(1)	(95)	(123)
Balance at End of Period	$ 282	$ 124	$ 177