Segment Reporting - Financial Information by Regional Segment (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Gross Revenue	$ 2,856.0	$ 2,805.2	$ 5,569.5	$ 5,410.1
Intercompany Revenue	(505.3)	(493.8)	(970.3)	(929.3)
Total revenue	2,350.7	2,311.4	4,599.2	4,480.8
Depreciation, Amortization, Depletion and Accretion	269.9	265.6	532.9	518.7
Operating Income (Loss)	382.1	389.2	727.6	762.0
Capital Expenditures	240.5	229.6	512.0	499.2
Total Assets	20,645.4	20,666.6	20,645.4	20,666.6	$ 20,535.9
Group 1 | Operating Segments
Segment Reporting Information [Line Items]
Gross Revenue	1,315.0	1,279.5	2,560.0	2,468.8
Intercompany Revenue	(265.1)	(260.2)	(509.5)	(493.9)
Total revenue	1,049.9	1,019.3	2,050.5	1,974.9
Depreciation, Amortization, Depletion and Accretion	104.8	99.7	207.1	194.4
Operating Income (Loss)	227.0	218.1	435.1	422.1
Capital Expenditures	130.8	114.3	220.3	192.9
Total Assets	9,201.9	9,337.7	9,201.9	9,337.7
Group 2 | Operating Segments
Segment Reporting Information [Line Items]
Gross Revenue	1,492.4	1,480.7	2,916.8	2,854.9
Intercompany Revenue	(236.7)	(230.1)	(454.2)	(428.9)
Total revenue	1,255.7	1,250.6	2,462.6	2,426.0
Depreciation, Amortization, Depletion and Accretion	136.3	138.6	269.1	269.4
Operating Income (Loss)	249.8	231.3	486.5	478.4
Capital Expenditures	95.6	88.7	164.6	177.5
Total Assets	9,899.9	9,914.6	9,899.9	9,914.6
Corporate Entities | Corporate Entities
Segment Reporting Information [Line Items]
Gross Revenue	48.6	45.0	92.7	86.4
Intercompany Revenue	(3.5)	(3.5)	(6.6)	(6.5)
Total revenue	45.1	41.5	86.1	79.9
Depreciation, Amortization, Depletion and Accretion	28.8	27.3	56.7	54.9
Operating Income (Loss)	(94.7)	(60.2)	(194.0)	(138.5)
Capital Expenditures	14.1	26.6	127.1	128.8
Total Assets	$ 1,543.6	$ 1,414.3	$ 1,543.6	$ 1,414.3