Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2017	Jun. 30, 2016
Statement Of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 1,314	$ 2,016
Preferred stock, par value
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Common stock, par value
Common stock, shares authorized	300,000,000	300,000,000
Common stock, shares issued	74,081,451	72,840,257
Treasury stock, shares	10,940,062	10,965,925