Consolidated Balance Sheets (Parenthetical) - USD ($)	Mar. 31, 2017	Mar. 31, 2016
Statement Of Financial Position [Abstract]
Allowance for doubtful debts, accounts receivable	$ 3,001,000	$ 1,821,000
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	120,000,000	120,000,000
Common stock, shares issued	53,569,067	53,448,672
Common stock, shares outstanding	18,937,233	19,562,413
Treasury stock, shares	34,631,834	33,886,259