CONTRACT ASSETS - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Increase in revenues in excess of billings, long-term service agreements			$ 2,606
Increase in revenues in excess of billings, long-term equipment contracts			1,328
Cumulative catch up adjustment driven by lower forecasted costs and increased forecasted revenue			1,930
Increase in long-term service agreements due to timing of revenue recognized for work performed relative to billings and collections			676
Increase in revenue in excess of billings for equipment contracts due to timing of revenue recognized for work performed relative to the timing of billing and collections			1,328
Remaining increase in contract assets primarily due to increase in deferred inventory costs and non-recurring engineering costs			712
Change in estimated profitability driven primarily by cost execution and increased productivity | Adjustment
Error Corrections and Prior Period Adjustments Restatement [Line Items]
Change in estimated profitability	$ 649	$ 588	$ 1,930	$ 1,714