Other Revenues and Other Expenses Other Revenues (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 546	$ 525	$ 1,108	$ 1,075
Other revenues	621	615	1,260	1,275
Vision fee for service arrangements
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	143	138	302	292
Prepaid legal plans
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	130	118	261	238
Fee-based investment management
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	103	100	203	202
Recordkeeping and administrative services (1)
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	38	43	75	90
Administrative services-only contracts
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	64	59	128	118
Other revenue from service contracts from customers
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	68	67	139	135
Other Income
Disaggregation of Revenue [Line Items]
Other revenues	$ 75	$ 90	$ 152	$ 200