LEASES - 2019 Narrative (Details) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2019 USD ($)
Leases [Abstract]
Operating right-of-use lease assets included within other long-term assets	$ 404	$ 404
Operating right-of-use lease liabilities included within trade accounts payable and accrued expenses	120	120
Operating right-of-use lease liabilities included within other long-term liabilities	324	324
Fixed operating lease costs	37	115
Variable lease costs	21	56
Sublease rental income	$ 10	$ 29
Weighted average remaining lease term (in years)	4 years 9 months 18 days	4 years 9 months 18 days
Weighted average discount rate (percent)	4.20%	4.20%
Operating lease cash payments		$ 112