Summary of Significant Accounting Policies (Narrative) (Details) - USD ($) shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease accumulated other comprehensive income				$ (8,825)	$ (12,809)	$ (12,707)
Anticipated amounts due from insureds related to losses under deductible policies				$ 1,100	$ 1,100
Structured settlement annuities, interest rate, low end				6.40%	6.40%
Discounted reserves for unfunded structured settlements				$ 485	$ 503
Discounted reserves for unfunded structure settlements, discount amount				590	621
Amount of interest recognized on the discounted reserves of unfunded structured settlements				$ 36	$ 36	35
Interest rates at which workers' compensation lifetime claim reserves are discounted at				3.50%	3.50%
Workers' compensation liability				$ 211	$ 228
Discounted reserves for workers’ compensation lifetime claim reserves, discount amount				93	97
Amount of interest accretion recognized on the discounted reserves of workers’ compensation lifetime claim reserves				$ 9	$ 12	$ 15
Long term care claim reserves weighted average discounted interest rate				5.90%	5.80%
Discounted reserves for long term care claim reserves				$ 2,800	$ 2,700
Premium deficiency				$ 450	$ 428
Liability for future policy benefits, gross premium valuation, pretax margin	$ 125	$ 72	$ 125
Minimum interest rate used to calculate reserves for long term care products				5.30%	5.30%
Liability balance for guaranty fund				$ 74	$ 79
Percentage of billed receivables compared to total reinsurance receivable				5.00%
Policyholder dividends, rate on policy earnings				2.00%	1.00%	1.00%
Increase (decrease) in shadow adjustment, net of tax				$ 2,416	$ 296
Reduction of net unrealized gains on investments included in AOCI due to shadow adjustments				61	2,477
Foreign currency transaction gain (loss), before tax				$ (22)	$ (1)	$ 13
Operating lease, right-of-use asset, statement of financial position [Extensible List]				Other Assets	Other Assets
Operating lease, liability, statement of financial position [Extensible List]				Other liabilities	Other liabilities
Weighted average number diluted shares outstanding adjustment (in shares)				1,000	1,000	1,000
Interest paid, net				$ 109	$ 110	$ 124
Income taxes paid				$ 277	278	108
Furniture and Fixtures
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, plant and equipment, useful life				7 years
Office Equipment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, plant and equipment, useful life				5 years
Computer Software, Intangible Asset
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, plant and equipment, useful life				10 years
Minimum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Warranty coverage term				1 month
Requisite service period for stock- based compensation expense				3 years
Minimum | Computer Software, Intangible Asset
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, plant and equipment, useful life				3 years
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Warranty coverage term				10 years
Maximum | Computer Software, Intangible Asset
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property, plant and equipment, useful life				5 years
CNAF Consolidated | Loews
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Noncontrolling interest, ownership percentage by parent				90.00%
Accumulated Other Comprehensive (Loss) Income
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease accumulated other comprehensive income				$ 3,557	$ (320)	(803)	$ (51)
Accumulated Other Comprehensive (Loss) Income | Revision of Prior Period, Accounting Standards Update, Adjustment
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Decrease accumulated other comprehensive income						$ 2,300