Assumptions Used in Estimating the Fair Value of Stock Award Grants (Detail) - $ / shares	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Share based Compensation Arrangement by Share based Payment Award, Fair Value Assumptions, Method Used [Line Items]
Interest rates minimum	1.70%	1.20%	1.10%
Interest rates maximum	2.90%	2.20%	1.80%
Lower Limit
Share based Compensation Arrangement by Share based Payment Award, Fair Value Assumptions, Method Used [Line Items]
Dividends per share (quarterly amounts)	$ 0.39	$ 0.36	$ 0.31
Upper Limit
Share based Compensation Arrangement by Share based Payment Award, Fair Value Assumptions, Method Used [Line Items]
Dividends per share (quarterly amounts)	$ 0.42	$ 0.39	$ 0.36