Pension, Other Postretirement Benefits and Savings Plans (Change in Fair Value of Pension Plan Assets) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
U.S.
Defined Benefit Plan Disclosure [Line Items]
Ending balance	$ 6,250	$ 4,800
U.S. | Commingled Funds
Defined Benefit Plan Disclosure [Line Items]
Ending balance	0	0
U.S. | Real Estate
Defined Benefit Plan Disclosure [Line Items]
Ending balance	0	37
U.S. | Fair Value, Inputs, Level 3 | Partnership Interests
Defined Benefit Plan Disclosure [Line Items]
Beginning balance	209	191
Realized gains (losses)	31	6
Unrealized gains (losses) relating to instruments still held at the reporting date	(15)	12
Purchases, sales, issuances and settlements (net)	4	0
Foreign currency translation	0	0
Ending balance	229	209
U.S. | Fair Value, Inputs, Level 3 | Commingled Funds
Defined Benefit Plan Disclosure [Line Items]
Ending balance	0	0
U.S. | Fair Value, Inputs, Level 3 | Real Estate
Defined Benefit Plan Disclosure [Line Items]
Ending balance	0	0
U.S. | Fair Value, Inputs, Level 3 | Other Plan Investments
Defined Benefit Plan Disclosure [Line Items]
Beginning balance	6	3
Realized gains (losses)	0	0
Unrealized gains (losses) relating to instruments still held at the reporting date	0	0
Purchases, sales, issuances and settlements (net)	(4)	3
Foreign currency translation	0	0
Ending balance	2	6
Non-U.S.
Defined Benefit Plan Disclosure [Line Items]
Ending balance	2,721	2,455
Non-U.S. | Commingled Funds
Defined Benefit Plan Disclosure [Line Items]
Ending balance	129	171
Non-U.S. | Real Estate
Defined Benefit Plan Disclosure [Line Items]
Ending balance	136	173
Non-U.S. | Fair Value, Inputs, Level 3 | Commingled Funds
Defined Benefit Plan Disclosure [Line Items]
Beginning balance	163	143
Realized gains (losses)	1	0
Unrealized gains (losses) relating to instruments still held at the reporting date	7	16
Purchases, sales, issuances and settlements (net)	(42)	0
Foreign currency translation	(7)	4
Ending balance	122	163
Non-U.S. | Fair Value, Inputs, Level 3 | Real Estate
Defined Benefit Plan Disclosure [Line Items]
Beginning balance	170	138
Realized gains (losses)	1	0
Unrealized gains (losses) relating to instruments still held at the reporting date	18	9
Purchases, sales, issuances and settlements (net)	(47)	19
Foreign currency translation	(8)	4
Ending balance	134	170
Non-U.S. | Fair Value, Inputs, Level 3 | Other Plan Investments
Defined Benefit Plan Disclosure [Line Items]
Beginning balance	19	19
Realized gains (losses)	0	0
Unrealized gains (losses) relating to instruments still held at the reporting date	0	0
Purchases, sales, issuances and settlements (net)	5	0
Foreign currency translation	(3)	0
Ending balance	$ 21	$ 19