Income Taxes - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Sep. 30, 2020	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
Effective income tax rate - provision (benefit)	23.60%	26.50%	27.20%
Unrecognized tax benefits	$ 14.2	$ 58.0	$ 7.4		$ 4.4
Accrued interest and penalties related to uncertain tax positions	0.4
Significant change in unrecognized tax benefits is reasonably possible, amount of unrecorded benefit	0.8
Deferred tax assets, valuation allowance	0.0	$ 0.0
IRS
Operating Loss Carryforwards [Line Items]
Income tax examination, liability refund				$ 12.9
State | California
Operating Loss Carryforwards [Line Items]
Tax credit carryforward	$ 1.0