Other Retirement Plans (Tables)

6 Months Ended

Jun. 30, 2017

Multiemployer Plans [Abstract]

Schedule of Covered Employees and Contributions, Multiemployer Plans

Total contributions to multiemployer plans, and the related number of employees covered by these plans, including with respect to the Company’s Canadian operations, for the periods indicated were as follows:

	Multiemployer Plans
	Covered Employees		Contributions (in millions)
	Low	High	Pension		Other Multiemployer		Total
For the Three Months Ended June 30:
2017	3,669	7,057	$	28.3	$	2.7	$	31.0
2016	1,410	4,170	$	12.2	$	2.5	$	14.7
For the Six Months Ended June 30:
2017	550	7,057	$	32.0	$	5.3	$	37.3
2016	1,112	4,170	$	17.0	$	4.7	$	21.7