DISCONTINUED OPERATIONS, SIGNIFICANT DISPOSALS AND OTHER BUSINESS EXITS - Income before Taxes, Assets and Liabilities Held-for-Sale (Details) - Australia Consumer Banking Business - Discontinued Operations, Held-for-sale - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Results of Discontinued Operations
Income before taxes	$ 95	$ 78	$ 236	$ 153
Assets
Allowance	249		249
Cash and deposits with banks	21		21
Loans (net of allowance of $249 million at September 30, 2021)	8,291		8,291
Goodwill and intangible assets	257		257
Other assets	85		85
Total assets	8,654		8,654
Liabilities
Deposits	6,912		6,912
Long-term debt	521		521
Other liabilities	143		143
Total liabilities	$ 7,576		$ 7,576