LEASES - 2019 Narrative (Details) $ in Millions	3 Months Ended	6 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)
Leases [Abstract]
Operating right-of-use lease assets included within other long-term assets	$ 406	$ 406
Operating right-of-use lease liabilities included within trade accounts payable and accrued expenses	121	121
Operating right-of-use lease liabilities included within other long-term liabilities	324	324
Fixed operating lease costs	39	78
Variable lease costs	19	35
Sublease rental income	$ 10	$ 19
Weighted average remaining lease term (in years)	4 years 9 months 18 days	4 years 9 months 18 days
Weighted average discount rate (percent)	4.30%	4.30%
Operating lease cash payments		$ 75