Valuation and Qualifying Accounts (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Valuation and Qualifying Accounts Disclosure [Line Items]
Charged to/from Other Accounts	$ 10	$ (8)	$ 83
Allowance for Trade Receivables [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance January 1,	29	32	33
Charged to/reversed from Expenses	7	5	15
Charged to/from Other Accounts	7	(1)	(3)
Payments/ Other	(3)	(7)	(13)
Balance December 31,	40	29	32
Allowance for Notes Receivable [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance January 1,	175	202	139
Charged to/reversed from Expenses	26	28	36
Charged to/from Other Accounts			78
Payments/ Other	(42)	(55)	(51)
Balance December 31,	159	175	202
Restructuring and other special charges [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance January 1,	89	29	34
Charged to/reversed from Expenses	(12)	68	(75)
Charged to/from Other Accounts	3	(7)	8
Payments/ Other	(2)	(1)	62
Balance December 31,	$ 78	$ 89	$ 29