Subsequent Events (Details) (USD $)			1 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Feb. 28, 2014 Subsequent Event [Member]	Feb. 25, 2014 Subsequent Event [Member]
Subsequent Event [Line Items]
Commercial paper	$ 225,000,000	$ 0		$ 900,000,000
Total consideration received from contribution of operations			1,200,000,000
Proceeds from Divestiture of Businesses			25,000,000
Number of Class D shares received from contribution of operations			25,577,521
Master limited partnership, general partner ownership percentage			2.00%
Dollar amount of potential future purchases of Class D units			$ 200,000,000