Profit Sharing, Retirement Savings Plans and Defined Benefit Pension Plans - Fair Values of Pension Plan Assets, by Asset Category and Level of Fair Values (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 836.6	$ 762.0
Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2.1	1.9
Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	347.5	323.1
Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	206.4	180.2
NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	280.6	256.8
Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	11.0	43.4
Cash and cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	2.1	1.9
Cash and cash equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8.9	41.5
Cash and cash equivalents | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Cash and cash equivalents | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Fixed income funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	417.3	323.8
Fixed income funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Fixed income funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	281.5	210.2
Fixed income funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Fixed income funds | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	135.8	113.6
Equity funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	122.3	146.9
Equity funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Equity funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	48.0	61.5
Equity funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Equity funds | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	74.3	85.4
Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	286.0	247.9
Other | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Other | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9.1	9.9
Other | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	206.4	180.2
Other | NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 70.5	$ 57.8