Summary of Significant Accounting Policies - Schedule of Earnings Per Share Basic and Diluted (Detail) - shares	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Earnings Per Share [Abstract]
Basic weighted shares	19,418,000	19,826,000	20,669,000
Treasury stock impact of stock options	152,000	178,000	221,000
Diluted weighted shares	19,570,000	20,004,000	20,890,000