INCOME TAXES - Unrecognized Tax Benefits Reconciliation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns
Balance at beginning of period	$ 4,692	$ 6,778
Additions for tax positions of the current year	260	248
Additions for tax positions of prior years(a)	791	521
Reductions for tax positions of prior years	(113)	(2,016)
Settlements with tax authorities	(57)	(823)
Expiration of the statute of limitations	(124)	(16)
Balance at end of period	5,449	$ 4,692
Baker Hughes
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns
Additions for tax positions of prior years(a)	$ 326