AVAILABLE-FOR-SALE SECURITIES, Contractual Maturities (Details) - USD ($) $ in Millions	Dec. 31, 2020	Sep. 30, 2020
Carrying value
Total	$ 8,000	$ 7,650
RJ Bank
Amortized cost
Within one year	25
After one but within five years	193
After five but within ten years	2,555
After ten years	5,132
Cost basis	7,905	7,531
Carrying value
Within one year	25
After one but within five years	197
After five but within ten years	2,595
After ten years	5,183
Total	$ 8,000	7,650
Weighted-average yield
Within one year (in hundredths)	2.13%
After one but within five years (in hundredths)	2.06%
After five but within ten years (in hundredths)	1.44%
After ten years (in hundredths)	1.28%
Total (in hundredths)	1.35%
RJ Bank | Agency residential MBS
Amortized cost
Within one year	$ 0
After one but within five years	37
After five but within ten years	1,639
After ten years	2,745
Cost basis	4,421	4,064
Carrying value
Within one year	0
After one but within five years	38
After five but within ten years	1,669
After ten years	2,783
Total	4,490	4,135
RJ Bank | Agency commercial MBS
Amortized cost
Within one year	25
After one but within five years	148
After five but within ten years	845
After ten years	143
Cost basis	1,161	948
Carrying value
Within one year	25
After one but within five years	151
After five but within ten years	853
After ten years	145
Total	1,174	969
RJ Bank | Agency CMOs
Amortized cost
Within one year	0
After one but within five years	1
After five but within ten years	63
After ten years	2,244
Cost basis	2,308	2,504
Carrying value
Within one year	0
After one but within five years	1
After five but within ten years	64
After ten years	2,255
Total	2,320	2,530
RJ Bank | Other securities
Amortized cost
Within one year	0
After one but within five years	7
After five but within ten years	8
After ten years	0
Cost basis	15	15
Carrying value
Within one year	0
After one but within five years	7
After five but within ten years	9
After ten years	0
Total	$ 16	$ 16