Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	3 Months Ended		9 Months Ended
	Apr. 30, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Leases [Abstract]
Capital lease agreement period				3 years
Operating lease expense		$ 31	$ 28	$ 94	$ 101
Contractual obligation	$ 140
Contractual obligation, period	10 years
Minimum
Leases [Abstract]
Interest rate		1.00%		1.00%
Expiration date of lease				2014
Maximum
Leases [Abstract]
Interest rate		13.00%		13.00%
Expiration date of lease				2029
Buildings
Leases [Abstract]
Capital lease agreement period				15 years