Landfill and Environmental Costs - Final Capping, Closure and Post-Closure Costs (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Activity in asset retirement obligation liabilities, which includes liabilities for final capping, closure and post-closure
Asset retirement obligation liabilities, beginning of year			$ 1,181.6	$ 1,144.3
Non-cash additions			19.6	19.4
Acquisitions and other adjustments			0.2	11.6
Asset retirement obligation adjustments			(2.0)	(5.5)
Payments			(35.3)	(26.2)
Accretion expense	$ 19.8	$ 19.7	39.6	39.4
Asset retirement obligation liabilities, end of period	1,203.7	1,183.0	1,203.7	1,183.0
Less: current portion	(91.8)	(92.8)	(91.8)	(92.8)
Long-term portion	$ 1,111.9	$ 1,090.2	$ 1,111.9	$ 1,090.2