Changes in Accumulated Other Comprehensive Income (Loss) by Component (Reclassifications) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Revenue	$ 2,530.0	$ 2,565.7	$ 2,517.8	$ 2,427.5	$ 2,560.0	$ 2,562.0	$ 2,526.7	$ 2,392.8	$ 10,040.9	$ 10,041.5	$ 9,387.7
Cost of operations									(6,150.0)	(6,214.6)	(5,764.0)
Interest expense									(383.8)	(361.9)	(371.3)
Tax (expense) benefit									(283.3)	(3.1)	(352.7)
Net income	$ 301.1	$ 262.9	$ 235.7	$ 237.9	$ 664.5	$ 223.3	$ 203.4	$ 187.8	1,037.6	1,279.0	613.2
Total gain (loss) reclassified into earnings									3.8	(5.3)	(26.5)
Amount Reclassified from Accumulated Other Comprehensive Income (Loss) | Gain (loss) on cash flow hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Income before income taxes									5.1	(8.8)	(43.9)
Tax (expense) benefit									(1.3)	3.5	17.4
Net income									3.8	(5.3)	(26.5)
Amount Reclassified from Accumulated Other Comprehensive Income (Loss) | Gain (loss) on cash flow hedges | Recycling commodity hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Revenue									1.1	(2.8)	0.0
Amount Reclassified from Accumulated Other Comprehensive Income (Loss) | Gain (loss) on cash flow hedges | Fuel hedges
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Cost of operations									4.3	(3.3)	(34.1)
Amount Reclassified from Accumulated Other Comprehensive Income (Loss) | Gain (loss) on cash flow hedges | Terminated interest rate locks
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest expense									$ (0.3)	$ (2.7)	$ (9.8)