Income Taxes - Gross Carryforwards (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($)
Operating Loss Carryforwards [Line Items]
Increase (decrease) in valuation allowance	$ (86.5)
Recognition of deferred tax asset due to release of valuation allowance	51.5
Expire Through Tax Year 2040
Operating Loss Carryforwards [Line Items]
Tax credit carryforwards	62.0
Net operating loss carryforwards	368.6
No Expiration
Operating Loss Carryforwards [Line Items]
State tax credit carryforwards	9.0
U.S. interest carryforward	78.1
U.S. Federal and Non-U.S. | No Expiration
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	$ 1,317.5