Share-based Compensation - Weighted Average Assumptions Used (Details) - Non-qualified Stock Options [Member] |
7 Months Ended | 12 Months Ended | |
|---|---|---|---|
Jun. 30, 2015 |
Jun. 30, 2017 |
Jun. 30, 2016 |
|
| Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | |||
| Expected life (in years) | 6 years 6 months | 6 years 4 months 24 days | 6 years 6 months |
| Expected volatility | 28.30% | 32.30% | 32.20% |
| Average risk-free interest rate | 1.90% | 2.20% | 1.80% |
| Dividend yield | 0.00% | 0.00% | 0.00% |