Employee Benefits - Summary of Expense Related to Multi-Employer Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Expense related to multi-employer plans	$ 631.1	$ 614.8	$ 580.7
Health and Welfare
Defined Benefit Plan Disclosure [Line Items]
Expense related to multi-employer plans	503.5	499.3	482.6
Pension
Defined Benefit Plan Disclosure [Line Items]
Expense related to multi-employer plans	$ 127.6	$ 115.5	$ 98.1