DISCONTINUED OPERATIONS AND SIGNIFICANT DISPOSALS - Significant Disposals (Details) - USD ($) $ in Millions			12 Months Ended
		Sep. 21, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Discontinued operations
Pre-tax gain (loss) on sale	[1]		$ 0	$ 0	$ 247
Mexico Asset Management Business | Disposal Group, Disposed of by Sale, Not Discontinued Operations
Discontinued operations
Assets		$ 137
Liabilities		$ 41
Pre-tax gain (loss) on sale					250
After tax gain (loss) on sale of disposal					150
Term of services framework agreement		10 years
Income before taxes			$ 0	$ 0	$ 123

[1] See Note 2 to the Consolidated Financial Statements for further information on significant disposals.