STOCKHOLDERS' EQUITY - Share Repurchases (Details) - USD ($) shares in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 14, 2017
Equity, Class of Treasury Stock [Line Items]
Purchase Not to Exceed					$ 3,000,000,000
Cost	$ 201,000,000	$ 241,000,000	$ 294,000,000	$ 1,819,000,000
February 2017
Equity, Class of Treasury Stock [Line Items]
Purchase Not to Exceed	2,250,000,000		$ 2,250,000,000
Shares			0	960
Cost			$ 0	$ 240,000,000
December 2017
Equity, Class of Treasury Stock [Line Items]
Purchase Not to Exceed	$ 3,000,000,000		$ 3,000,000,000
Shares			680	0
Cost			$ 224,000,000	$ 0
Total Excluding ASR Activity
Equity, Class of Treasury Stock [Line Items]
Shares			680	960
Cost			$ 224,000,000	$ 240,000,000