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Summary Of Significant Accounting Policies (Narrative) (Details)		12 Months Ended
	Feb. 28, 2019	Dec. 31, 2021 USD ($) independent_insurance_agency state subsidiary reporting_locations	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2008
Significant Accounting Policies
Income Tax Examination, Penalties Expense		$ 0
Number of operating subsidaries \| subsidiary		2
Number of independent insurance agencies \| independent_insurance_agency		1,921
Number of reporting locations \| reporting_locations		2,721
Number of states in which entity operates \| state		46
Excess (deficit) of Separate Account Fair Value over (under) Contract Holder Account Value		$ 79,000,000	$ 99,000,000
Minimum participant age to elect					40 years
Other invested assets		329,000,000	348,000,000
Depreciation expense		33,000,000	33,000,000	$ 25,000,000
Land, building and equipment impairments		0	0	$ 0
Premium Receivable, Allowance for Credit Loss		14,000,000	19,000,000
Premium Receivable, Allowance for Credit Loss, Property Casualty Premiums Receivable			9,000,000
Covid-19 pandemic-related incurred loss and expenses		$ (7,000,000)	85,000,000
Minimum
Significant Accounting Policies
Estimated useful lives		3 years
Maximum
Significant Accounting Policies
Estimated useful lives		39 years 6 months
Life Policy Loans
Significant Accounting Policies
Other invested assets		$ 31,000,000	33,000,000
Venture Capital Funds
Significant Accounting Policies
Other invested assets		227,000,000	128,000,000
Real Estate Investment
Significant Accounting Policies
Other invested assets		36,000,000	25,000,000
Other than Securities Investment
Significant Accounting Policies
Other invested assets		$ 35,000,000	$ 162,000,000
10 Largest States
Significant Accounting Policies
Generated percentage of total earned premiums		52.10%	53.30%
Ohio, Largest State
Significant Accounting Policies
Generated percentage of total earned premiums		14.40%	14.80%
Illinois, North Carolina, Georgia, Pennsylvania, Indiana and New York \| Minimum
Significant Accounting Policies
Generated percentage of total earned premiums		4.00%
Illinois, North Carolina, Georgia, Pennsylvania, Indiana and New York \| Maximum
Significant Accounting Policies
Generated percentage of total earned premiums		6.00%
Largest Single Agency Relationship
Significant Accounting Policies
Generated percentage of total earned premiums		0.60%
All Other \| Maximum
Significant Accounting Policies
Generated percentage of total earned premiums		5.00%
Stock Options
Significant Accounting Policies
Weighted-average remaining contractual life for options expected to vest		10 years
Property Casualty Insurance Segment
Significant Accounting Policies
Number of operating subsidaries \| subsidiary		2
Stock Options
Significant Accounting Policies
Awards vesting period		3 years
Restricted Stock Units (RSUs)
Significant Accounting Policies
Awards vesting period		3 years
Cincinnati Global
Significant Accounting Policies
Goodwill		$ 30,000,000	$ 30,000,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets		$ 31,000,000	$ 31,000,000
Broker Relationships and Internally developed technology \| Cincinnati Global \| Minimum
Significant Accounting Policies
Useful life	5 years
Broker Relationships and Internally developed technology \| Cincinnati Global \| Maximum
Significant Accounting Policies
Useful life	15 years