Pension and Other Postretirement Employee Benefit Plans - Pretax Amortization from AOCI (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014
U.S. defined benefit pension plans
Estimated pretax amounts that will be amortized from AOCI into net periodic benefit cost
Net loss	$ 257
Prior service cost/(credit)	(34)
Total	223
Non-U.S. defined benefit pension plans
Estimated pretax amounts that will be amortized from AOCI into net periodic benefit cost
Net loss	37
Prior service cost/(credit)	(2)
Total	35
U.S. OPEB plans
Estimated pretax amounts that will be amortized from AOCI into net periodic benefit cost
Net loss	0
Prior service cost/(credit)	0
Total	0
Non-U.S. OPEB plans
Estimated pretax amounts that will be amortized from AOCI into net periodic benefit cost
Net loss	0
Prior service cost/(credit)	0
Total	$ 0