Share-Based Compensation Expense by Award Type (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Dec. 31, 2016
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation expense	$ 5,397	$ 3,833	$ 11,709	$ 7,982
Stock Options and Cash-Based Stock Appreciation Rights
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation expense	2,062	1,431	4,525	3,094
Restricted Share Awards and Cash-Based Restricted Share Unit Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation expense	2,181	1,682	4,744	3,560
Performance Share Awards and Cash-Based Performance Share Unit Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation expense	$ 1,154	$ 720	$ 2,440	$ 1,328