Stock-Based Compensation - Long-Term Incentive Plans Narrative (Details) - USD ($) $ in Millions	Mar. 31, 2020	Mar. 31, 2019
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation not yet recognized	$ 7.3	$ 8.0
LTIPs | RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation not yet recognized	3.9	4.1
LTIPs | Cash Award
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation not yet recognized	$ 1.9	$ 2.4