CONTRACT AND OTHER DEFERRED ASSETS & PROGRESS COLLECTIONS AND DEFERRED INCOME - Narrative (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2020	Dec. 31, 2019
Capitalized Contract Cost [Line Items]
Decrease in contract and other deferred assets	$ 665
Revenue recognized included in contract liability	3,898	$ 4,608
Power and Renewable Energy
Capitalized Contract Cost [Line Items]
Increase (decrease) in progress collections and deferred income due to timing of revenue recognition	(708)
Long-term | Services
Capitalized Contract Cost [Line Items]
Decrease due to billings	2,544
Increase due to revenues recognized	2,688
Long-term | Services | Aviation
Capitalized Contract Cost [Line Items]
Decrease due to billings	193
Non-cash pre-tax charge	(100)
Long-term | Services | Power
Capitalized Contract Cost [Line Items]
Decrease due to billings	$ 72