Employee Benefits and Share-Based Compensation - Summary of Shares Reserved for Future Issuance Under Equity Incentive Plans (Details) shares in Thousands	Jun. 30, 2019 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares reserved for future issuance	9,716
2009 Plan | Share options outstanding
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares reserved for future issuance	3,520
2009 Plan | Non-vested restricted share awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares reserved for future issuance	673
2009 Plan | Shares authorized for future issuance
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares reserved for future issuance	3,820
1997 Employee stock purchase plan | ESPP shares available for future issuance
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total shares reserved for future issuance	1,703