Debt Key Components of Long-term Debt (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended		6 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Long-term Debt	Dec. 31, 2013 Long-term Notes $2.5B	Dec. 31, 2013 Long-term Notes $2.0B	Dec. 31, 2013 Long-term Notes $1.0B
Debt Instrument [Line Items]
Debt Instrument, Unamortized Discount			$ 6
Fair Value Inputs, Discount Rate	1.00%			99.943%	99.76%	99.925%
Long-term debt	$ 5,494	$ 0		$ 2,499	$ 1,996	$ 999
Debt Instrument, Interest Rate During Period			2.54%