DERIVATIVE FINANCIAL INSTRUMENTS - Offsetting Assets (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Document Period End Date	Sep. 30, 2019
Offsetting Derivative Assets [Abstract]
Gross amounts of recognized assets	$ 1,123	$ 500
Gross amounts offset in the condensed consolidated balance sheets	546	291
Net amounts of assets presented in the condensed consolidated balance sheets	577	209
Gross amounts not offset in the condensed consolidated balance sheets, Financial instruments	(15)	(4)
Gross amounts not offset in the condensed consolidated balance sheets, cash collateral received	(31)	(53)
Net amount	$ 531	$ 152