Employee Benefit Plans (Change in Fair Value of Company's Level 3 Pension Assets) (Detail) - Level 3 - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	$ 612	$ 632
Realized gain	16	21
Unrealized gain for positions still held	8	13
Transfers out	13	(39)
Foreign currency loss	(14)	(15)
End balance	635	612
Real Estate
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	210	222
Realized gain	15	17
Unrealized gain for positions still held	12	8
Transfers out	(24)	(34)
Foreign currency loss	(4)	(3)
End balance	209	210
Other Debt Securities
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	23	27
Realized gain	1	1
Unrealized gain for positions still held	0	0
Transfers out	(1)	(1)
Foreign currency loss	(2)	(4)
End balance	21	23
Hedge Funds & Other Assets
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	379	383
Realized gain	0	3
Unrealized gain for positions still held	(4)	5
Transfers out	38	(4)
Foreign currency loss	(8)	(8)
End balance	$ 405	$ 379