Principles of Consolidation And Other Matters (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Operating funds related to regulatory requirements or as collateral under captive insurance arrangements	$ 302,000,000		$ 302,000,000		$ 303,000,000
Equity method investments lag period			3 months
Gain on investment income, net	$ 2,000,000	$ 19,000,000	$ 28,000,000	$ 30,000,000
Effective tax rate (as a percent)	25.50%	31.60%	24.60%	27.90%
Excess tax benefit related to share-based payments, percent	0.80%	0.60%	1.30%	0.90%
Charge related to revaluation of deferred tax assets and liabilities		$ 100,000,000
Unrecognized tax benefits	$ 102,000,000		$ 102,000,000		$ 94,000,000
Minimum
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Reasonably possible decrease in unrecognized tax benefits	0		0
Maximum
Significant Change in Unrecognized Tax Benefits is Reasonably Possible [Line Items]
Reasonably possible decrease in unrecognized tax benefits	$ 48,000,000		$ 48,000,000