Fiduciary Assets and Liabilities (Reclassification of Fiduciary Assets and Liabilities) (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Fiduciary Assets and Liabilities [Line Items]
Total current assets	$ 22,279	$ 18,959
Total assets	48,000	44,114
Total current liabilities	$ 20,605	17,832
As Reported
Fiduciary Assets and Liabilities [Line Items]
Total current assets		8,299
Total assets		33,454
Total current liabilities		7,172
As Reclassified
Fiduciary Assets and Liabilities [Line Items]
Total current assets		18,959
Total assets		44,114
Total current liabilities		$ 17,832