DERIVATIVE INSTRUMENTS - Summary of Balance Sheet Classification of Derivative Fair Value Amounts, as well as Gross Asset and Liability Fair Value Amounts (Detail) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Net derivatives notional amount	$ 49,815	$ 38,355
Derivative asset, fair value, gross asset including not subject to master netting arrangement	411	417
Derivative liability, fair value, gross liability including not subject to master netting arrangement	403	387
Asset derivatives fair value	264	234
Liability derivatives fair value	264	285
Cash flow hedges
Derivatives, Fair Value [Line Items]
Net derivatives notional amount	75	75
Asset derivatives fair value	0	1
Liability derivatives fair value	7	4
Cash flow hedges | Foreign currency swaps | Variable Interest Entity
Derivatives, Fair Value [Line Items]
Net derivatives notional amount	75	75
Asset derivatives fair value	0	1
Liability derivatives fair value	7	4
Fair value hedges
Derivatives, Fair Value [Line Items]
Net derivatives notional amount	14,654	11,656
Asset derivatives fair value	16	3
Liability derivatives fair value	65	36
Fair value hedges | Foreign currency forwards
Derivatives, Fair Value [Line Items]
Net derivatives notional amount	2,568	2,086
Asset derivatives fair value	16	0
Liability derivatives fair value	58	34
Fair value hedges | Foreign currency options
Derivatives, Fair Value [Line Items]
Net derivatives notional amount	11,843	9,070
Asset derivatives fair value	0	3
Liability derivatives fair value	7	1
Fair value hedges | Interest rate swaptions
Derivatives, Fair Value [Line Items]
Net derivatives notional amount	243	500
Asset derivatives fair value	0	0
Liability derivatives fair value	0	1
Net investment hedge
Derivatives, Fair Value [Line Items]
Net derivatives notional amount	5,497	0
Asset derivatives fair value	31	0
Liability derivatives fair value	9	0
Net investment hedge | Foreign currency forwards
Derivatives, Fair Value [Line Items]
Net derivatives notional amount	3,497	0
Asset derivatives fair value	30	0
Liability derivatives fair value	9	0
Net investment hedge | Foreign currency options
Derivatives, Fair Value [Line Items]
Net derivatives notional amount	2,000	0
Asset derivatives fair value	1	0
Liability derivatives fair value	0	0
Non-qualifying strategies
Derivatives, Fair Value [Line Items]
Net derivatives notional amount	29,589	26,624
Asset derivatives fair value	364	413
Liability derivatives fair value	322	347
Non-qualifying strategies | Foreign currency swaps | Variable Interest Entity
Derivatives, Fair Value [Line Items]
Net derivatives notional amount	2,587	2,587
Asset derivatives fair value	147	181
Liability derivatives fair value	132	101
Non-qualifying strategies | Foreign currency swaps | Consolidated Entity Excluding Variable Interest Entities (VIE)
Derivatives, Fair Value [Line Items]
Net derivatives notional amount	2,800	2,800
Asset derivatives fair value	80	103
Liability derivatives fair value	88	129
Non-qualifying strategies | Foreign currency forwards
Derivatives, Fair Value [Line Items]
Net derivatives notional amount	15,919	16,057
Asset derivatives fair value	124	126
Liability derivatives fair value	101	117
Non-qualifying strategies | Foreign currency options
Derivatives, Fair Value [Line Items]
Net derivatives notional amount	856	430
Asset derivatives fair value	0	0
Liability derivatives fair value	1	0
Non-qualifying strategies | Interest rate swaptions
Derivatives, Fair Value [Line Items]
Net derivatives notional amount	7	0
Asset derivatives fair value	0	0
Liability derivatives fair value	0	0
Non-qualifying strategies | Interest rate swaps
Derivatives, Fair Value [Line Items]
Net derivatives notional amount	7,420	4,750
Asset derivatives fair value	13	3
Liability derivatives fair value	$ 0	$ 0