Share-Based Compensation - Options Valuation (Details) - Stock options - $ / shares	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2016
Assumptions used to estimate fair values
Risk-free interest rate (as a percent)	2.10%	1.10%	1.70%
Expected volatility (as a percent)	57.60%	55.60%	48.30%
Forfeiture rate (as a percent)	6.50%	6.50%	6.50%
Expected term (in years)	5 years 4 months 24 days	5 years 2 months 12 days	5 years 2 months 12 days
Weighted average fair value (in dollars per share)	$ 11.25	$ 15.33	$ 26.24