BANK DEPOSITS BANK DEPOSITS, Schedule Maturities of Certificates of Deposit (Details) - USD ($) $ in Millions	Sep. 30, 2020	Sep. 30, 2019
Scheduled maturities of certificates of deposit, denominations greater than or equal to $100,000 [Abstract]
Three months or less	$ 59	$ 24
Over three through six months	26	26
Over six through twelve months	19	75
Over one through two years	43	32
Over two through three years	67	40
Over three through four years	37	66
Over four through five years	7	38
Total certificates of deposit, denominations greater than or equal to 100,000	258	301
Scheduled maturities of certificates of deposit, denominations less than 100,000 [Abstract]
Three months or less	76	19
Over three through six months	18	21
Over six through twelve months	26	37
Over one through two years	206	36
Over two through three years	170	93
Over three through four years	165	47
Over four through five years	98	51
Total certificates of deposit, denominations less than 100,000	$ 759	$ 304