Employee Benefit Plans (Change in Fair Value of Company's Level 3 Pension Assets) (Detail) (Level 3, USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	$ 632	$ 519
Realized gain	21	63
Unrealized gain for positions still held	13	32
Transfers in/(out)	(39)	15
Foreign currency gain	(15)	3
End balance	612	632
Real Estate
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	222	176
Realized gain	17	7
Unrealized gain for positions still held	8	18
Transfers in/(out)	(34)	21
Foreign currency gain	(3)	0
End balance	210	222
Other Debt Securities
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	27	27
Transfers in/(out)	(1)	(1)
Foreign currency gain	(4)	0
End balance	23	27
Hedge Funds & Other Assets
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	383	316
Realized gain	3	55
Unrealized gain for positions still held	5	14
Transfers in/(out)	(4)	(5)
Foreign currency gain	(8)	3
End balance	$ 379	$ 383