Employee Benefit Plans (Change in Accumulated Other Comprehensive Loss (Pretax) Relating to Defined Benefit Pension and Other Postretirement Benefits) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss / (gain) arising during the year	$ 67
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss / (gain) arising during the year	(104)
Impact of curtailments	0
Amortization of actuarial loss	(32)
Amortization of prior service cost	9
Foreign currency translation adjustments and other	(3)
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Net of Tax	2
Net change	(128)
Pensions
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss / (gain) arising during the year	171
Impact of curtailments	(7)
Amortization of actuarial loss	(125)
Amortization of prior service cost	2
Foreign currency translation adjustments and other	(59)
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Net of Tax	(18)
Net change	(36)
Pensions | Pensions
Defined Benefit Plan Disclosure [Line Items]
Amortization of prior service cost	$ (2)	$ (2)	$ (2)