INTANGIBLE ASSETS AND GOODWILL - Composition of Acquired Intangible Assets (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Acquired Finite-Lived Intangible Assets [Line Items]
Accumulated amortization	$ (579)	$ (447)
Contract acquisition costs and other, net	2,951	2,829
Acquired Indefinite-lived Intangible Assets [Line Items]
Total Intangible Assets	8,805	9,270
Indefinite-lived Intangible Brand Assets
Acquired Indefinite-lived Intangible Assets [Line Items]
Brands	5,854	6,441
Contract acquisition costs and other
Acquired Finite-Lived Intangible Assets [Line Items]
Contract acquisition costs and other	$ 3,530	$ 3,276