RETIREMENT BENEFITS - Funded Status and Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
U.S. Pension Plans
Change in plan assets
Company contributions					$ 33	$ 139
U.S. Pension Plans | Significant Plans Measured Quarterly
Change in projected benefit obligation
Projected benefit obligation at period end	$ 14,067				14,067
Change in plan assets
Plan assets at fair value at period end—Significant Plans	12,396				12,396
Funded status of the plans	(1,671)				(1,671)
Net amount recognized
Net amount recognized on the balance sheet—Significant Plans	(1,671)				(1,671)
Amounts recognized in Accumulated other comprehensive income (loss)
Net amount recognized in equity-pretax	(6,189)				(6,189)
Accumulated benefit obligation at period end	14,057				14,057
U.S. Qualified Pension Plan
Change in projected benefit obligation
Projected benefit obligation at beginning of year			$ 14,839		14,839
Benefits earned during the period	1			$ 1	3	4
Interest cost on benefit obligation	143			132	411	410
Curtailment loss	2
Quarter activity		$ (1,057)	201
Change in plan assets
Plan assets at fair value at beginning of year			13,071		13,071
First quarter activity		(256)	129
U.S. Qualified Pension Plan | Plans measured annually
Change in projected benefit obligation
Projected benefit obligation at beginning of year			0		0
Change in plan assets
Plan assets at fair value at beginning of year			0		0
U.S. Qualified Pension Plan | Significant Plans Measured Quarterly
Change in projected benefit obligation
Projected benefit obligation at beginning of year	13,983		14,839		14,839
Benefits earned during the period	1
Interest cost on benefit obligation	151
Actuarial (gain) loss	135
Benefits paid, net of participants’ contributions	(205)
Foreign exchange impact and other	0
Projected benefit obligation at period end		13,983
Change in plan assets
Plan assets at fair value at beginning of year	12,944		13,071		13,071
Actual return on plan assets	(356)
Company contributions	13
Plan participants’ contributions	0
Benefits paid	(205)
Foreign exchange impact and other	0
Plan assets at fair value at period end—Significant Plans		12,944
Funded status of the plans	(948)				(948)
Net amount recognized
Benefit asset	0				0
Benefit liability	(1,671)				(1,671)
Amounts recognized in Accumulated other comprehensive income (loss)
Prior service benefit (cost)	0				0
Net actuarial gain (loss)	(6,189)				(6,189)
U.S. Nonqualified Pension Plan | Significant Plans Measured Quarterly
Change in plan assets
Funded status of the plans	(723)				(723)
Non - U.S. Pension Plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year			7,252		7,252
Benefits earned during the period	42			43	129	136
Interest cost on benefit obligation	77			93	237	287
Curtailment loss	0
Quarter activity		0	(47)
Change in plan assets
Plan assets at fair value at beginning of year			7,057		7,057
Company contributions					85	164
First quarter activity		(23)	(154)
Non - U.S. Pension Plans | Plans measured annually
Change in projected benefit obligation
Projected benefit obligation at beginning of year			2,070		2,070
Change in plan assets
Plan assets at fair value at beginning of year			1,406		1,406
Non - U.S. Pension Plans | Significant Plans Measured Quarterly
Change in projected benefit obligation
Projected benefit obligation at beginning of year	5,135		5,182		5,182
Benefits earned during the period	23
Interest cost on benefit obligation	63
Actuarial (gain) loss	(105)
Benefits paid, net of participants’ contributions	(63)
Foreign exchange impact and other	(325)
Projected benefit obligation at period end	4,728	5,135			4,728
Change in plan assets
Plan assets at fair value at beginning of year	5,474		5,651		5,651
Actual return on plan assets	15
Company contributions	11
Plan participants’ contributions	1
Benefits paid	(64)
Foreign exchange impact and other	(346)
Plan assets at fair value at period end—Significant Plans	5,091	5,474			5,091
Funded status of the plans	363				363
Net amount recognized
Benefit asset	363				363
Benefit liability	0				0
Net amount recognized on the balance sheet—Significant Plans	363				363
Amounts recognized in Accumulated other comprehensive income (loss)
Prior service benefit (cost)	12				12
Net actuarial gain (loss)	(1,048)				(1,048)
Net amount recognized in equity-pretax	(1,036)				(1,036)
Accumulated benefit obligation at period end	4,420				4,420
U.S. Postretirement Benefit Plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year			917		917
Benefits earned during the period	0			0	0	0
Interest cost on benefit obligation	8			8	24	25
Curtailment loss	0
Quarter activity		(76)	3
Change in plan assets
Plan assets at fair value at beginning of year			10		10
Company contributions	174				217	34
First quarter activity		(3)	(4)
U.S. Postretirement Benefit Plans | Plans measured annually
Change in projected benefit obligation
Projected benefit obligation at beginning of year			0		0
Change in plan assets
Plan assets at fair value at beginning of year			0		0
U.S. Postretirement Benefit Plans | Significant Plans Measured Quarterly
Change in projected benefit obligation
Projected benefit obligation at beginning of year	844		917		917
Benefits earned during the period	0
Interest cost on benefit obligation	8
Actuarial (gain) loss	2
Benefits paid, net of participants’ contributions	(12)
Foreign exchange impact and other	0
Projected benefit obligation at period end	842	844			842
Change in plan assets
Plan assets at fair value at beginning of year	3		10		10
Actual return on plan assets	0
Company contributions	184
Plan participants’ contributions	0
Benefits paid	(13)
Foreign exchange impact and other	0
Plan assets at fair value at period end—Significant Plans	174	3			174
Funded status of the plans	(668)				(668)
Net amount recognized
Benefit asset	0				0
Benefit liability	(668)				(668)
Net amount recognized on the balance sheet—Significant Plans	(668)				(668)
Amounts recognized in Accumulated other comprehensive income (loss)
Prior service benefit (cost)	0				0
Net actuarial gain (loss)	(6)				(6)
Net amount recognized in equity-pretax	(6)				(6)
Accumulated benefit obligation at period end	842				842
Non-U.S. Postretirement Benefit Plans
Change in projected benefit obligation
Projected benefit obligation at beginning of year			1,527		1,527
Benefits earned during the period	3			4	10	11
Interest cost on benefit obligation	25			$ 30	82	90
Curtailment loss	0
Quarter activity		(74)	(25)
Change in plan assets
Plan assets at fair value at beginning of year			1,384		1,384
Company contributions					7	$ 2
First quarter activity		(43)	(54)
Non-U.S. Postretirement Benefit Plans | Plans measured annually
Change in projected benefit obligation
Projected benefit obligation at beginning of year			348		348
Change in plan assets
Plan assets at fair value at beginning of year			9		9
Non-U.S. Postretirement Benefit Plans | Significant Plans Measured Quarterly
Change in projected benefit obligation
Projected benefit obligation at beginning of year	1,080		1,179		1,179
Benefits earned during the period	2
Interest cost on benefit obligation	21
Actuarial (gain) loss	(6)
Benefits paid, net of participants’ contributions	(12)
Foreign exchange impact and other	(77)
Projected benefit obligation at period end	1,008	1,080			1,008
Change in plan assets
Plan assets at fair value at beginning of year	1,278		$ 1,375		1,375
Actual return on plan assets	(22)
Company contributions	0
Plan participants’ contributions	0
Benefits paid	(12)
Foreign exchange impact and other	(92)
Plan assets at fair value at period end—Significant Plans	1,152	$ 1,278			1,152
Funded status of the plans	144				144
Net amount recognized
Benefit asset	144				144
Benefit liability	0				0
Net amount recognized on the balance sheet—Significant Plans	144				144
Amounts recognized in Accumulated other comprehensive income (loss)
Prior service benefit (cost)	116				116
Net actuarial gain (loss)	(485)				(485)
Net amount recognized in equity-pretax	(369)				(369)
Accumulated benefit obligation at period end	$ 1,008				$ 1,008