Schedule II Valuation and Qualifying Accounts (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation and Qualifying Accounts Beginning Balance		$ 219	$ 266	$ 278
Additions charged to bad debt provision	[1]	53	53	120
Amounts (credited) charged to other income statement accounts	[1]	5	0	3
Deductions and other, net of recoveries	[2]	(79)	(100)	(135)
Valuation and Qualifying Accounts Ending Balance		198	219	266
Accounts Receivable [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation and Qualifying Accounts Beginning Balance		88	112	108
Additions charged to bad debt provision	[1]	25	20	39
Amounts (credited) charged to other income statement accounts	[1]	5	(3)	(2)
Deductions and other, net of recoveries	[2]	(38)	(41)	(33)
Valuation and Qualifying Accounts Ending Balance		80	88	112
Financing Receivable [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Valuation and Qualifying Accounts Beginning Balance		131	154	170
Additions charged to bad debt provision	[1]	28	33	81
Amounts (credited) charged to other income statement accounts	[1]	0	3	5
Deductions and other, net of recoveries	[2]	(41)	(59)	(102)
Valuation and Qualifying Accounts Ending Balance		$ 118	$ 131	$ 154

[1] Bad debt provisions relate to estimated losses due to credit and similar collectibility issues. Other charges (credits) relate to adjustments to reserves necessary to reflect events of non-payment such as customer accommodations and contract terminations.

[2] Deductions and other, net of recoveries primarily relates to receivable write-offs, but also includes the impact of foreign currency translation adjustments and recoveries of previously written off receivables.