Commitments and Contingencies (Details) (USD $) In Millions, except Share data, unless otherwise specified	0 Months Ended		1 Months Ended	2 Months Ended	6 Months Ended	12 Months Ended		32 Months Ended
	Jul. 24, 2013	Oct. 25, 2011	Jul. 21, 2014	Dec. 31, 2011	Jun. 30, 2014	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2014
Commitments and Contingencies
Amount authorized under stock repurchase plan	$ 300	$ 200
Total number of Shares Purchased			223,821	671,776	1,137,037	1,159,871	459,252	3,427,936
Average Price Paid per Share (in dollars per share)				$ 48.72	$ 59.20	$ 51.83	$ 50.27
Aggregate Cost			$ 14.0	$ 32.7	$ 67.3	$ 60.1	$ 23.1	$ 183.2