Pensions And Other Postretirement Benefits Assets and Fair Value Measurements (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
US Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	$ 46,013	$ 50,210
Plan assets measured at net asset value	14,678	15,044
Other plan assets (liabilities), net	381	569
Net Plan Assets	61,072	65,823	$ 64,166
US Pension Plans [Member] | Common and preferred stocks [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	7,663	10,066
US Pension Plans [Member] | Government and agency debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	14,318	16,143
US Pension Plans [Member] | Corporate and other debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	22,964	22,808
US Pension Plans [Member] | Other investments, net [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	1,068	1,193
US Pension Plans [Member] | Investment funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets measured at net asset value	6,321	6,172
US Pension Plans [Member] | Private Equity and Debt Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets measured at net asset value	4,529	5,347
US Pension Plans [Member] | Real estate investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets measured at net asset value	3,828	3,525
US Pension Plans [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	8,103	10,695
US Pension Plans [Member] | Level 1 [Member] | Common and preferred stocks [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	7,637	10,033
US Pension Plans [Member] | Level 1 [Member] | Government and agency debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	0	0
US Pension Plans [Member] | Level 1 [Member] | Corporate and other debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	0	0
US Pension Plans [Member] | Level 1 [Member] | Other investments, net [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	466	662
US Pension Plans [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	37,429	38,718
US Pension Plans [Member] | Level 2 [Member] | Common and preferred stocks [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	18	30
US Pension Plans [Member] | Level 2 [Member] | Government and agency debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	14,318	16,143
US Pension Plans [Member] | Level 2 [Member] | Corporate and other debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	22,963	22,725
US Pension Plans [Member] | Level 2 [Member] | Other investments, net [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	130	(180)
US Pension Plans [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	481	797
US Pension Plans [Member] | Level 3 [Member] | Common and preferred stocks [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	8	3
US Pension Plans [Member] | Level 3 [Member] | Government and agency debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	0	0
US Pension Plans [Member] | Level 3 [Member] | Corporate and other debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	1	83
US Pension Plans [Member] | Level 3 [Member] | Other investments, net [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	472	711
Non-US Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	7,029	8,472
Plan assets measured at net asset value	6,099	6,211
Other plan assets (liabilities), net	(138)	(14)
Net Plan Assets	12,990	14,669	$ 14,986
Non-US Pension Plans [Member] | Common and preferred stocks [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	1,081	1,962
Non-US Pension Plans [Member] | Government and agency debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	3,258	3,614
Non-US Pension Plans [Member] | Corporate and other debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	1,954	1,986
Non-US Pension Plans [Member] | Other investments, net [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	736	910
Non-US Pension Plans [Member] | Investment funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets measured at net asset value	4,475	4,440
Non-US Pension Plans [Member] | Private Equity and Debt Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets measured at net asset value	529	509
Non-US Pension Plans [Member] | Real estate investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets measured at net asset value	1,095	1,262
Non-US Pension Plans [Member] | Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	1,126	2,097
Non-US Pension Plans [Member] | Level 1 [Member] | Common and preferred stocks [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	1,079	1,959
Non-US Pension Plans [Member] | Level 1 [Member] | Government and agency debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	0	0
Non-US Pension Plans [Member] | Level 1 [Member] | Corporate and other debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	0	0
Non-US Pension Plans [Member] | Level 1 [Member] | Other investments, net [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	47	138
Non-US Pension Plans [Member] | Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	5,259	5,649
Non-US Pension Plans [Member] | Level 2 [Member] | Common and preferred stocks [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	1	3
Non-US Pension Plans [Member] | Level 2 [Member] | Government and agency debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	3,258	3,614
Non-US Pension Plans [Member] | Level 2 [Member] | Corporate and other debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	1,953	1,986
Non-US Pension Plans [Member] | Level 2 [Member] | Other investments, net [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	47	46
Non-US Pension Plans [Member] | Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	644	726
Non-US Pension Plans [Member] | Level 3 [Member] | Common and preferred stocks [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	1	0
Non-US Pension Plans [Member] | Level 3 [Member] | Government and agency debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	0	0
Non-US Pension Plans [Member] | Level 3 [Member] | Corporate and other debt securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	1	0
Non-US Pension Plans [Member] | Level 3 [Member] | Other investments, net [Member]
Defined Benefit Plan Disclosure [Line Items]
Net plan assets subject to leveling	$ 642	$ 726