Segment Information (Premiums, Fees and Other Revenues by US and Foreign Operations) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Premiums, Fees & Other Revenues	$ 57,616	$ 50,384	$ 49,486
UNITED STATES
Segment Reporting Information [Line Items]
Premiums, Fees & Other Revenues	43,319	35,252	34,717
Japan
Segment Reporting Information [Line Items]
Premiums, Fees & Other Revenues	5,532	6,426	6,750
Other Foreign
Segment Reporting Information [Line Items]
Premiums, Fees & Other Revenues	$ 8,765	$ 8,706	$ 8,019