Share-Based Compensation - Summary of Director Stock Units Activity (Details) - Non-employee Board of Director's Plan - $ / shares	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Number of Units
Balance at the beginning of the period (in shares)	338,553	334,943	287,436
Granted (in shares)	21,813	27,285	40,323
Distributed (in shares)	(35,489)	(30,022)
Dividend equivalents (in shares)	4,869	6,347	7,184
Balance at the end of the period (in shares)	329,746	338,553	334,943
Weighted Average Grant Date Fair Value
Balance at the beginning of the period (in dollars per share)	$ 42.47	$ 38.64	$ 35.48
Granted (in dollars per share)	49.14	39.69	32.54
Distributed (in dollars per share)	35.22	34.19
Dividend equivalents (in dollars per share)	0.00	0.00	0.00
Balance at the end of the period (in dollars per share)	$ 33.05	$ 42.47	$ 38.64