Summary of Significant Accounting Policies - Fair Value of Financial Instruments (Details) - USD ($) $ in Millions	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2021	May 31, 2020	Sep. 30, 2016
Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	$ 553.9	$ 580.0	$ 619.9
3.25% Senior Notes | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate, percentage	3.25%				3.25%
Fair value	$ 553.9	580.0	619.9
1.50% Convertible Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Stated interest rate, percentage	1.50%			1.50%
1.50% Convertible Senior Notes | Senior Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value	$ 85.8	$ 126.6	$ 149.6