GOODWILL AND INTANGIBLE ASSETS (Goodwill) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Goodwill [Roll Forward]
Goodwill, Balance at beginning of period	$ 6,335	$ 6,000
Goodwill acquired during the period	57	335
Goodwill, Balance at end of period	$ 6,392	$ 6,335