Fair Value Measurements - Fair Value of Debt (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021	Nov. 08, 2013
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Public bonds	$ 2,544.4	$ 2,913.5	$ 2,300.0
Public bonds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Public bonds	2,225.4	2,847.2
Private placement note | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying value (excluding premium)	0.0	162.6
Reported Value Measurement | Public bonds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Public bonds	2,544.4	2,760.0
Reported Value Measurement | Private placement note | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying value (excluding premium)	$ 0.0	$ 153.5