Segment Information (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Revenues and adjusted segment income by reportable segment
Revenues	$ 4,417.9	$ 3,759.1	$ 12,872.6	$ 10,739.0	$ 14,700.0
Segment income	116.2	97.6	339.2	281.9
Intersegment Elimination
Revenues and adjusted segment income by reportable segment
Revenues	(6.4)	(5.7)	(53.1)	(27.1)
Segment income	0.2	0.1	(0.2)	(0.3)
Retail | Operating segments
Revenues and adjusted segment income by reportable segment
Revenues	4,305.3	3,698.8	12,566.0	10,678.1
Segment income	100.8	84.0	301.0	259.0
Other | Operating segments
Revenues and adjusted segment income by reportable segment
Revenues	119.0	66.0	359.7	88.0
Segment income	$ 15.2	$ 13.5	$ 38.4	$ 23.2