Employee Benefits - Summary of Expense Related to Multi-Employer Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Expense related to multi-employer plans	$ 612.3	$ 631.1	$ 614.8
Health and Welfare
Defined Benefit Plan Disclosure [Line Items]
Expense related to multi-employer plans	488.7	503.5	499.3
Pension
Defined Benefit Plan Disclosure [Line Items]
Expense related to multi-employer plans	$ 123.6	$ 127.6	$ 115.5