Other Financial Data Schedule of Allowance for Doubtful Accounts (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Allowance for Doubtful Accounts Receivable [Roll Forward]
Balance at beginning of period	$ 70	$ 89	$ 74	$ 90
Provision charged to operations	3	4	11	8
Accounts written off, net of recoveries	(13)	(4)	(22)	(9)
Foreign currency translation	5	(1)	2	(1)
Balance at end of period	$ 65	$ 88	$ 65	$ 88