AVAILABLE-FOR-SALE SECURITIES, Contractual Maturities (Details) - USD ($) $ in Millions	Mar. 31, 2021	Sep. 30, 2020
Carrying value
Total	$ 8,158	$ 7,650
RJ Bank
Amortized cost
Within one year	42
After one but within five years	244
After five but within ten years	2,730
After ten years	5,148
Cost basis	8,164	7,531
Carrying value
Within one year	42
After one but within five years	250
After five but within ten years	2,725
After ten years	5,141
Total	$ 8,158	7,650
Weighted-average yield
Within one year (in hundredths)	2.10%
After one but within five years (in hundredths)	2.14%
After five but within ten years (in hundredths)	1.27%
After ten years (in hundredths)	1.03%
Total (in hundredths)	1.15%
RJ Bank | Agency residential MBS
Amortized cost
Within one year	$ 0
After one but within five years	45
After five but within ten years	1,811
After ten years	2,906
Cost basis	4,762	4,064
Carrying value
Within one year	0
After one but within five years	47
After five but within ten years	1,834
After ten years	2,903
Total	4,784	4,135
RJ Bank | Agency commercial MBS
Amortized cost
Within one year	42
After one but within five years	191
After five but within ten years	856
After ten years	105
Cost basis	1,194	948
Carrying value
Within one year	42
After one but within five years	195
After five but within ten years	827
After ten years	104
Total	1,168	969
RJ Bank | Agency CMOs
Amortized cost
Within one year	0
After one but within five years	1
After five but within ten years	55
After ten years	2,137
Cost basis	2,193	2,504
Carrying value
Within one year	0
After one but within five years	1
After five but within ten years	56
After ten years	2,134
Total	2,191	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	8
After ten years	0
Total	$ 15	$ 16