Stock Based Compensation - Unrecognized Compensation Cost (Details) $ in Millions	Dec. 31, 2019 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 116.6
Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	61.2
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	$ 55.4