Employee Benefits - Amounts Recognized for Pension Plans (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Compensation And Retirement Disclosure [Abstract]
Noncurrent assets	$ 63.2	$ 6.1
Current liabilities	0.7	1.0
Noncurrent liabilities	14.1	233.9
Total	$ 48.4	$ (228.8)

Amount of asset, recognized in statement of financial position, for overfunded defined benefit pension and other postretirement plans.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant