Changes in Balances of Accumulated Other Comprehensive Income by Component (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Equity And Accumulated Other Comprehensive Income [Line Items]
Balance at January 1, 2013	$ 2,235
Other comprehensive income (loss)	(165)
Amounts reclassified to net income	(14)
Net other comprehensive income (loss)	(148)	104
Net other comprehensive income (loss)	(6)	8
Net other comprehensive income (loss)	11	23
Net other comprehensive income (loss)	(36)	(6)
Net other comprehensive income (loss)	(179)	129
Balance at March 31, 2013	2,056
Foreign currency translation adjustments
Equity And Accumulated Other Comprehensive Income [Line Items]
Balance at January 1, 2013	793
Other comprehensive income (loss)	(148)
Net other comprehensive income (loss)	(148)
Balance at March 31, 2013	645
Unrealized loss on cash flow hedges
Equity And Accumulated Other Comprehensive Income [Line Items]
Balance at January 1, 2013	88
Other comprehensive income (loss)	(31)
Amounts reclassified to net income	25
Net other comprehensive income (loss)	(6)
Balance at March 31, 2013	82
Unrealized gain on marketable securities
Equity And Accumulated Other Comprehensive Income [Line Items]
Balance at January 1, 2013	101
Other comprehensive income (loss)	14
Amounts reclassified to net income	(3)
Net other comprehensive income (loss)	11
Balance at March 31, 2013	112
Defined benefit pension and postretirement plans
Equity And Accumulated Other Comprehensive Income [Line Items]
Balance at January 1, 2013	1,253
Amounts reclassified to net income	(36)
Net other comprehensive income (loss)	(36)
Balance at March 31, 2013	$ 1,217