Cincinnati Financial (CINF) 10-K 25 Feb 21 2020 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Dec. 31, 2020	Feb. 19, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Document Transition Report	false
Entity File Number	000-04604
Entity Registrant Name	Cincinnati Financial Corporation
Entity Incorporation, State or Country Code	OH
Entity Tax Identification Number	31-0746871
Entity Address, Address Line One	6200 S. Gilmore Road
Entity Address, City or Town	Fairfield
Entity Address, State or Province	OH
Entity Address, Postal Zip Code	45014-5141
City Area Code	513
Local Phone Number	870-2000
Title of 12(b) Security	Common stock, $2.00 par
Trading Symbol	CINF
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 9,621,748,017
Entity Common Stock, Shares Outstanding		161,201,922
Entity Central Index Key	0000020286
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false
Documents Incorporated by Reference	Portions of the definitive Proxy Statement for Cincinnati Financial Corporation’s Annual Meeting of Shareholders to be held on May 8, 2021, are incorporated by reference into Part III of this Form 10-K.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Investments
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	$ 12,338	$ 11,698
Equity securities, at fair value (cost: 2020—$3,927; 2019—$3,581)	8,856	7,752
Other invested assets	348	296
Total investments	21,542	19,746
Cash and cash equivalents	900	767
Investment income receivable	136	133
Finance receivable	95	77
Premiums receivable	1,879	1,777
Reinsurance recoverable	517	610
Prepaid reinsurance premiums	65	54
Deferred policy acquisition costs	805	774
Land, building and equipment, net, for company use (accumulated depreciation: 2020—$285; 2019—$276)	213	207
Other assets	438	381
Separate accounts	952	882
Total assets	27,542	25,408
Insurance reserves
Loss and loss expense reserves	6,746	6,147
Life policy and investment contract reserves	2,915	2,835
Unearned premiums	2,960	2,788
Other liabilities	982	928
Deferred income tax	1,299	1,079
Note payable	54	39
Long-term debt and lease obligations	845	846
Separate accounts	952	882
Total liabilities	16,753	15,544
Commitments and contingent liabilities (Note 16)	0	0
Shareholders' Equity
Common stock, par value—$2 per share; (authorized: 2020 and 2019—500 million shares; issued: 2020 and 2019—198.3 million shares)	397	397
Paid-in capital	1,328	1,306
Retained earnings	10,085	9,257
Accumulated other comprehensive income	769	448
Treasury stock, at cost (2020—37.4 million shares and 2019—35.4 million shares)	(1,790)	(1,544)
Total shareholders' equity	10,789	9,864
Total liabilities and shareholders' equity	$ 27,542	$ 25,408

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Statement of Financial Position [Abstract]
Fixed maturities, amortized cost	$ 11,312	$ 11,108
Equity securities, cost	3,927	3,581
Land, building and equipment, accumulated depreciation	$ 285	$ 276
Common stock, par value	$ 2	$ 2
common stock, authorized	500,000	500,000
Common stock, issued	198,300	198,300
Treasury stock, shares	37,400	35,400

Consolidated Statements Of Inco

Consolidated Statements Of Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues
Earned premiums	$ 5,980	$ 5,604	$ 5,170
Investment income, net of expenses	670	646	619
Investment gains and losses, net	865	1,650	(402)
Fee revenues	11	15	15
Other revenues	10	9	5
Total revenues	7,536	7,924	5,407
Benefits and Expenses
Insurance losses and contract holders' benefits	4,134	3,638	3,490
Underwriting, acquisition and insurance expenses	1,829	1,738	1,597
Interest expense	54	53	53
Other operating expenses	20	23	16
Total benefits and expenses	6,037	5,452	5,156
Income Before Income Taxes	1,499	2,472	251
Provision (Benefit) for Income Taxes
Current	147	132	11
Deferred	136	343	(47)
Total provision (benefit) for income taxes	283	475	(36)
Net Income	$ 1,216	$ 1,997	$ 287
Per Common Share
Net income—basic (in usd per share)	$ 7.55	$ 12.24	$ 1.76
Net income—diluted (in usd per share)	$ 7.49	$ 12.10	$ 1.75

Consolidated Statements Of Comp

Consolidated Statements Of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net Income	$ 1,216	$ 1,997	$ 287
Other Comprehensive Income (Loss)
Change in unrealized gains and losses on investments, net of tax (benefit) of $92, $114 and $(72), respectively	344	430	(267)
Amortization of pension actuarial gains and losses and prior service cost, net of tax (benefit) of $(7), $2 and $(1), respectively	(25)	5	(3)
Change in life deferred acquisition costs, life policy reserves and other, net of tax (benefit) of $1, $(3) and $2, respectively	2	(9)	7
Other comprehensive income (loss)	321	426	(263)
Comprehensive Income	$ 1,537	$ 2,423	$ 24

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Unrealized gains on investments available-for-sale, net of tax	$ 92	$ 114	$ (72)
Amortization of pension actuarial loss and prior service cost, net of tax	(7)	2	(1)
Change in life deferred acquisition costs, life policy reserves and other, net of tax	$ 1	$ (3)	$ 2

Consolidated Statements Of Shar

Consolidated Statements Of Shareholders' Equity - USD ($) shares in Thousands, $ in Millions	Total	Common Stock	Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income	Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting for equity securities as of January 1, 2018				$ 2,503	$ (2,503)
Adjusted beginning of year				7,683	285
Increase to allowance through retained earnings for ASU 2016-13, after-tax				0
Beginning Balance at Dec. 31, 2017		$ 397	$ 1,265	5,180	2,788	$ (1,387)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based awards		0	(17)			21
Share-based compensation			28
Other			5			4
Net Income	$ 287			287
Dividends declared				(345)
Other comprehensive income (loss)	(263)				(263)
Shares acquired - share repurchase authorization						(125)
Shares acquired - share-based compensation plans						(5)
Ending Balance at Dec. 31, 2018	7,833	$ 397	1,281	7,625	22	(1,492)
Beginning Balance (in shares) at Dec. 31, 2017		163,900
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based awards (in shares)		700
Shares acquired—share repurchase authorization (in shares)		(1,800)
Shares acquired - share-based compensation plans (in shares)		0
Other (in shares)		0
Ending Balance (in shares) at Dec. 31, 2018		162,800
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting for equity securities as of January 1, 2018				0	0
Adjusted beginning of year				7,625	22
Increase to allowance through retained earnings for ASU 2016-13, after-tax				0
Share-based awards		$ 0	(12)			21
Share-based compensation			30
Other			7			3
Net Income	1,997			1,997
Dividends declared				(365)
Other comprehensive income (loss)	426				426
Shares acquired - share repurchase authorization						(67)
Shares acquired - share-based compensation plans						(9)
Ending Balance at Dec. 31, 2019	9,864	$ 397	1,306	9,257	448	(1,544)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based awards (in shares)		700
Shares acquired—share repurchase authorization (in shares)		(600)
Shares acquired - share-based compensation plans (in shares)		(100)
Other (in shares)		100
Ending Balance (in shares) at Dec. 31, 2019		162,900
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of change in accounting for equity securities as of January 1, 2018				0	0
Adjusted beginning of year				9,255	448
Increase to allowance through retained earnings for ASU 2016-13, after-tax	(2)			(2)
Share-based awards		$ 0	(15)			15
Share-based compensation			31
Other			6			5
Net Income	1,216			1,216
Dividends declared				(386)
Other comprehensive income (loss)	321				321
Shares acquired - share repurchase authorization						(261)
Shares acquired - share-based compensation plans						(5)
Ending Balance at Dec. 31, 2020	$ 10,789	$ 397	$ 1,328	$ 10,085	$ 769	$ (1,790)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based awards (in shares)	274	500
Shares acquired—share repurchase authorization (in shares)		(2,500)
Shares acquired - share-based compensation plans (in shares)		(100)
Other (in shares)		100
Ending Balance (in shares) at Dec. 31, 2020		160,900

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash Flows From Operating Activities
Net Income	$ 1,216	$ 1,997	$ 287
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	81	72	63
Investment gains and losses, net	(851)	(1,640)	408
Share-based compensation	31	30	28
Interest credited to contract holders	43	44	47
Deferred income tax expense	136	343	(47)
Changes in:
Investment income receivable	(3)	(1)	2
Premiums and reinsurance receivable	(23)	(174)	(109)
Deferred policy acquisition costs	(39)	(61)	(48)
Other assets	(26)	(22)	(1)
Loss and loss expense reserves	599	163	434
Life policy and investment contract reserves	116	107	96
Unearned premiums	172	184	112
Other liabilities	(5)	74	0
Current income tax receivable/payable	44	92	(91)
Net cash provided by operating activities	1,491	1,208	1,181
Cash Flows From Investing Activities
Sale of fixed maturities	179	102	36
Call or maturity of fixed maturities	912	1,241	1,127
Sale of equity securities	515	203	403
Purchase of fixed maturities	(1,382)	(1,742)	(1,510)
Purchase of equity securities	(699)	(382)	(441)
Investment in finance receivables	(50)	(34)	(33)
Collection of finance receivables	35	29	25
Investment in buildings and equipment	(20)	(24)	(20)
Change in other invested assets, net	(50)	(72)	(38)
Net cash used in investing activities	(560)	(679)	(451)
Cash Flows From Financing Activities
Payment of cash dividends to shareholders	(375)	(355)	(336)
Shares acquired - share repurchase authorization	(261)	(67)	(125)
Changes in note payable	15	7	8
Proceeds from stock options exercised		11	9
Contract holders' funds deposited	85	86	84
Contract holders' funds withdrawn	(159)	(174)	(183)
Other	(110)	(54)	(60)
Net cash used in financing activities	(798)	(546)	(603)
Net change in cash and cash equivalents	133	(17)	127
Cash and cash equivalents at beginning of year	767	784	657
Cash and cash equivalents at end of year	900	767	784
Supplemental Disclosures of Cash Flow Information
Interest paid	53	53	53
Income taxes paid	84	34	98
Noncash Activities
Equipment acquired under finance lease obligations	19	14	21
Share-based compensation	19	9	5
Other assets and other liabilities	$ 57	$ 29	$ 48

Summary Of Significant Accounti

Summary Of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary Of Significant Accounting Policies	Summary of Significant Accounting Policies Nature of Operations Cincinnati Financial Corporation (CFC) operates through The Cincinnati Insurance Company and Cincinnati Global Underwriting Ltd. SM (Cincinnati Global) insurance subsidiaries and two complementary subsidiary companies. Cincinnati Global, our London-based global specialty underwriter, was acquired effective February 28, 2019. The Cincinnati Insurance Company leads our insurance group that also includes two subsidiaries: The Cincinnati Casualty Company and The Cincinnati Indemnity Company. This group markets a broad range of standard market commercial and personal policies. The group focuses on delivery of quality customer service to our select group of 1,848 independent insurance agencies with 2,578 reporting locations acros s 45 states . Other subsidiaries of The Cincinnati Insurance Company include: The Cincinnati Life Insurance Company, which markets life insurance and fixed annuities; and The Cincinnati Specialty Underwriters Insurance Company, which offers excess and surplus lines property casualty insurance products. The Cincinnati Insurance Company also conducts the business of our reinsurance assumed operations, Cincinnati Re ® . The two CFC complementary subsidiaries are CSU Producer Resources Inc., which provides insurance brokerage services to our independent agencies so their clients can access our excess and surplus lines insurance products, and CFC Investment Company, which offers commercial leasing and financing services to our agents, their clients and other customers. The World Health Organization declared the 2019 novel coronavirus (SARS-CoV-2 or COVID-19) outbreak a Public Health Emergency of International Concern on January 30, 2020, and a pandemic on March 11, 2020. The pandemic outbreak has caused an economic downturn on a global scale and although many businesses have resumed operations at some capacity, there is still uncertainty surrounding future government and private company restrictions. The pandemic, and unprecedented actions taken to contain the virus, has also continued to cause market disruption and volatility. For 2020, the company estimated that pandemic-related incurred losses and expenses totaled $85 million. The company continues to monitor the impact of the pandemic as it unfolds. The company cannot predict the impact the pandemic will have on its future consolidated financial condition, results of operations and cash flows, however the impact could be material. Basis of Presentation Our consolidated financial statements include the accounts of the parent and its wholly owned subsidiaries and are presented in conformity with accounting principles generally accepted in the United States of America (GAAP). The 2019 consolidated financial statements include Cincinnati Global's results for the period from February 28, 2019, through December 31, 2019. Foreign exchange rates related to Cincinnati Global's operations did not have a material impact to our consolidated financial statements. All intercompany balances and transactions have been eliminated in consolidation. The preparation of the consolidated financial statements in conformity with GAAP requires us to make estimates and assumptions that affect amounts reported in the consolidated financial statements and accompanying notes. Our actual results could differ from those estimates. Investments Our portfolio investments are primarily in publicly traded fixed-maturity and equity security investments. Fixed-maturity investments (taxable bonds, tax-exempt bonds, redeemable preferred equities and commercial mortgage- backed securities) classified as available for sale and equity investments (common and nonredeemable preferred equities) are recorded at fair value in the consolidated financial statements. Changes in fair value of fixed-maturity securities are reported in other comprehensive income while equity securities are reported in net income. The number of fixed-maturity securities with fair values below 100% of amortized cost can be expected to fluctuate as interest rates rise or fall. Because of our strong capital and long-term investment horizon, our general intent is to hold fixed-maturity investments until maturity, regardless of short-term fluctuations in fair values. An available for sale fixed maturity is impaired if the fair value of the security is below amortized cost. The impaired loss is charged to net income when we have the intent to sell the security or it is more likely than not we will be required to sell the security before recovery of the amortized cost. For impaired securities we intend to hold, an allowance for credit related losses is recorded in investment losses when the company determines a credit loss has been incurred based on certain factors such as adverse conditions, credit rating downgrades or failure of the issuer to make scheduled principal or interest payments. A credit loss is determined using a discounted cash flow analysis by comparing the present value of expected cash flows with the amortized cost basis, limited to the difference between fair value and amortized cost. Noncredit losses are recognized in other comprehensive income as a change in unrealized gains and losses on investments. As securities are sold, we recognize the gain or loss in income based on the trade date. Included within our other invested assets were $162 million and $164 million held on deposit at Lloyd's, $128 million and $71 million of private equity investments, $33 million and $32 million of life policy loans and $25 million and $29 million of real estate through direct property ownership and development projects in the United States at December 31, 2020 and 2019, respectively. Lloyd's deposits primarily consist of highly liquid short-term investment instruments. The private equity investments provide their financial statements to us and generally report investments on their balance sheets at fair value. We use the equity method of accounting for private equity and real estate development investments. Life policy loans are carried at the receivable value. Investment income, net of expenses, consists mainly of interest and dividends. We record interest on an accrual basis and record dividends at the ex-dividend date. We amortize premiums and discounts on fixed-maturity securities using the effective interest method over the expected life of the security. Fair Value Disclosures Fair value is defined as the exit price or the amount that would be (1) received to sell an asset or (2) paid to transfer a liability in an orderly transaction between marketplace participants at the measurement date. When determining an exit price, we rely upon observable market data whenever possible. We primarily base fair value for investments in equity and fixed-maturity securities (including redeemable preferred stock and assets held in separate accounts) on quoted market prices or on prices from the company’s nationally recognized pricing vendors, outside resources that supply global securities pricing, dividend, corporate action and descriptive information to support fund pricing, securities operations, research and portfolio management. The company obtains and reviews the pricing services' valuation methodologies and related inputs and validates these prices by replicating a sample across each asset class using a discounted cash flow model. When a price is not available from these sources, as in the case of securities that are not publicly traded, we determine the fair value using various inputs including quotes from independent brokers. The fair value of investments not priced by the company’s nationally recognized pricing vendors is immaterial. For the purpose of Accounting Standards Codification (ASC) 825, Financial Instruments disclosure, we estimate the fair value of our long-term senior notes on market pricing of similar debt instruments that are actively trading. We estimate the fair value of our note payable on the year-end outstanding balance because it is short term and tied to a variable interest rate. We estimate the fair value of liabilities for investment contracts and annuities using discounted cash flow calculations across a wide range of economic interest rate scenarios with a provision for our nonperformance risk. We estimate the fair value for policyholder loans on insurance contracts using a discounted cash flow model. Determination of fair value for structured settlements assumes the discount rates used to calculate the present value of expected payments are the risk-free spot rates plus an A3 rated bond spread for financial issuers at December 31, 2020, to account for nonperformance risk. See Note 3, Fair Value Measurements, for further details. Cash and Cash Equivalents Cash and cash equivalents are highly liquid instruments that include liquid debt instruments with original maturities of less than three months. These are carried at cost, which approximates fair value. Property Casualty Insurance The consolidated property casualty companies actively write property casualty insurance through independent agencies i n 45 states. Our 10 largest states generated 53.3% and 54.8% of total earned premiums in 2020 and 2019, respectively. Ohio, our largest state, accounted for 14.8% and 15.1% of total earned premiums in 2020 and 2019, respectively. Illinois, Georgia, North Carolina, Pennsylvania and Indiana each accounted for between 4% and 6% of total earned premiums in 2020. Our largest single agency relationship accounted for approximately 1.3% of our total property casualty earned premiums in 2020. No aggregate agency relationship locations under a single ownership structure accounted for more than 4% of our total property casualty earned premiums in 2020. We record revenues for installment charges as fee revenues in the consolidated statements of income. Property casualty written premiums are deferred and recorded as earned premiums primarily on a pro rata basis over the terms of the policies. We record as unearned premiums the portion of written premiums that applies to unexpired policy terms. Expenses associated with successfully acquiring insurance policies – commissions, premium taxes and underwriting costs – are deferred and amortized over the terms of the policies. We assess recoverability of deferred acquisition costs at a level consistent with the way we acquire, service and manage insurance policies and measure profitability. We analyze our acquisition cost assumptions to reflect actual experience, and we evaluate potential premium deficiencies. Certain property casualty policies are not entered into policy underwriting systems as of the effective date of coverage. An estimate is recorded for these unprocessed written premiums. A large majority of the estimate is unearned and has no material impact on earned premiums. An allowance for credit losses on uncollectible property casualty premiums is updated and reviewed on a quarterly basis. At January 1, 2020, the allowance was $9 million. At December 31, 2020, the allowance increased to $19 million, of which a significant portion was due to consideration of pandemic-related factors. Other changes in the amount during 2020 were immaterial. We establish reserves to cover the expected cost of claims, losses and expenses related to investigating, processing and resolving claims. Although the appropriate amount of reserves is inherently uncertain, we base our decisions on past experience and current facts. Reserves are based on claims reported prior to the end of the year and estimates of incurred but not reported (IBNR) claims. We regularly review and update reserves using the most current information available. Any resulting adjustments are reflected in current calendar year insurance losses and policyholder benefits. We estimate that we may recover some of our costs through salvage and subrogation. Policyholder Dividends Certain workers’ compensation policies include the possibility of a policyholder earning a return of a portion of premium in the form of a policyholder dividend. The dividend generally is calculated by determining the profitability of a policy year along with the associated premium. We reserve for all probable future policyholder dividend payments. We record policyholder dividends as other underwriting expenses. Life Insurance We offer several types of life insurance and we account for each according to the duration of the contract. Short-duration life and health contracts are written to cover claims that arise during a short, fixed term of coverage. We generally have the right to change the amount of premium charged or cancel the coverage at the end of each contract term. We record premiums for short-duration life and health contracts similarly to property casualty contracts. Long-duration contracts are written to provide coverage for an extended period of time. Traditional long-duration contracts require policyholders to pay scheduled gross premiums, generally not less frequently than annually, over the term of the coverage. Premiums for these contracts, such as whole life insurance are recognized as revenue when due. Some traditional long-duration contracts, such as ten-pay whole life insurance, have premium payment periods shorter than the period over which coverage is provided. For these contracts, the excess of premium over the amount required to pay expenses and benefits is recognized over the term of the coverage rather than over the premium payment period. We establish a liability for traditional long-duration contracts as we receive premiums. The amount of this liability is the present value of future expenses and benefits less the present value of future net premiums. Net premium is the portion of gross premium required to provide for all expenses and benefits. We estimate future expenses and benefits and net premium using assumptions for expected expenses, mortality, morbidity, withdrawal rates and investment income. We include a provision for deviation, meaning we allow for some uncertainty in making our assumptions. We establish our assumptions when the contract is issued, and we generally maintain those assumptions for the life of the contract. We use both our own experience and industry experience, adjusted for historical trends, in arriving at our assumptions for expected mortality, morbidity and withdrawal rates. We use our own experience and historical trends for setting our assumption for expected expenses. We base our assumption for expected investment income on our own experience, adjusted for current and future economic conditions. We capitalize acquisition costs for traditional long-duration contracts. We charge these capitalized costs associated with successfully acquiring traditional long-duration contract insurance policies in proportion to premium revenue recognized. We use the same assumptions used in establishing the liability for the contract. We update our acquisition cost assumptions periodically to reflect actual experience, and we evaluate our deferred acquisition costs for recoverability. Universal life contracts are long-duration contracts for which contractual provisions are not fixed, unlike whole life insurance. Universal life contracts allow policyholders to vary the amount of premium, within limits, without our consent. However, we may vary the mortality, expense charges and the interest crediting rate, within limits, used to accumulate policy values. We do not record universal life premiums as revenue. Instead we recognize as revenue the mortality charges, administration charges and surrender charges when received. Some of our universal life contracts assess administration charges in the early years of the contract that are compensation for services we will provide in the later years of the contract. These administration charges are deferred and are recognized over the period when we provide those future services. We maintain a policy reserve liability equal to the policyholder account value. There is no provision for adverse deviation. Some of our universal life policies contain no-lapse guarantee provisions. For these policies, we establish a reserve in addition to the account balance, based on expected no-lapse guarantee benefits and expected policy assessments. We capitalize acquisition costs associated with successfully acquiring universal life long-duration contracts. We charge these capitalized costs to expenses over the term of coverage of the contract in accordance with the recognition of gross profit from the contract or notional benefit base. When we charge deferred policy acquisition costs to expenses, we use assumptions based on our best estimates of long-term experience. We review and modify these assumptions on a regular basis. An allowance for credit losses on uncollectible life insurance premiums is updated and reviewed on a quarterly basis. The allowance, including changes in the amount during 2020, was immaterial to our consolidated financial condition, results of operations and cash flows. Separate Accounts We have issued universal life contracts with guaranteed minimum returns, referred to as bank-owned life insurance contracts (BOLIs). A BOLI is designed so the bank is the policy owner and the policy beneficiary. We legally segregate and record as separate accounts the assets and liabilities for some of our BOLIs, based on the specific contract provisions. We guarantee minimum investment returns, account values and death benefits for our separate account BOLIs. Our other BOLIs are general account products. We carry the assets of separate account BOLIs at fair value. The liabilities on separate account BOLIs primarily are the contract holders’ claims to the related assets and are carried at an amount equal to the contract holders’ account value. At December 31, 2020 and 2019, the current fair value of th e BOLI invested assets and cash exceeded the current fair value of the contract holders’ account value by approximately $99 million and $52 million, respectively. If the BOLI projected fair value were to fall below the value we guaranteed, a liability would be established with a corresponding charge to the company’s earnings. Generally, investment income and investment gains and losses of the separate accounts accrue directly to the contract holder, and we do not include them in the consolidated statements of income. Revenues and expenses related to separate accounts consist of contractual fees and mortality, surrender and expense risk charges. Also, each separate account BOLI includes a negotiated capital gain and loss sharing arrangement between the company and the bank. A percentage of each separate account’s investment gains and losses representing contract fees and assessments accrues to us and is transferred from the separate account to our general account and is recognized as revenue or expense. We record as revenues separate account investment management fees in fee revenues of the consolidated statements of income. Reinsurance The Cincinnati Insurance Company offers reinsurance assumed for casualty (predominantly domestic exposure), specialty and property (worldwide exposure). Treaties are written on a pro rata and excess of loss basis. We also continue to assume risk with limited exposure as a reinsurer for involuntary state pools. Written premium is recorded, net of contract specific retrocessions, on an ultimate estimate basis and primarily earned on a pro rata basis over the coverage period of the treaty. Expenses are recorded as per contract terms and deferred over the earning period of the premium. We establish known loss reserves when reported. We establish reserves for losses in excess of reported activity in the form of IBNR. Reserves are established using actuarial analysis, which includes models and methods traditionally used for the types of exposures written. We establish reserves for event specific occurrences using modeling data and company specific data when available. We enter into other reinsurance transactions to reduce risk and uncertainty by buying property casualty reinsurance and retrocessional reinsurance as well as life reinsurance. Reinsurance and retrocessional reinsurance contracts do not relieve us from our obligation to policyholders, but rather help protect our financial strength to perform that duty. All of these ceded reinsurance contracts transfer the economic risk of loss. Premiums that we cede are deferred and recorded as earned premiums on a pro rata basis over the terms of the contracts. We estimate loss amounts recoverable from our reinsurers based on the reinsurance policy terms. Historically, our claims with reinsurers have been paid. An allowance for credit losses on uncollectible reinsurance premiums and recoverable assets is updated and reviewed on a quarterly basis. The allowances, including changes in the amounts during 2020, were immaterial to our consolidated financial condition, results of operations and cash flows. Income Taxes We calculate deferred income tax liabilities and assets using tax rates in effect when temporary differences in the consolidated financial statement income and taxable income are expected to reverse. We recognize deferred income taxes for numerous temporary differences between our taxable income and consolidated financial statement income and other changes in shareholders’ equity. Such temporary differences relate primarily to unrealized gains and losses on investments and differences in the recognition of deferred acquisition costs, unearned premiums, insurance reserves and basis differences in the carrying value of investments held. We charge deferred income taxes associated with balances that impact other comprehensive income, such as unrealized gains and losses of fixed-maturity investments, to shareholders’ equity in accumulated other comprehensive income (AOCI). We charge deferred taxes associated with other differences to income. See Note 11, Income Taxes, for further detail on our uncertain tax positions and other income tax items. Although no Internal Revenue Service (IRS) penalties currently are accrued, if incurred, they would be recognized as a component of income tax expense. Earnings per Share Net income per common share is based on the weighted average number of common shares outstanding during each of the respective years. We calculate net income per common share (diluted) assuming the exercise or conversion of share‑based awards using the treasury stock method. Land, Building and Equipment We record land at cost, and record building and equipment at cost less accumulated depreciation. Equipment held under finance leases also is classified as property and equipment with the related lease obligations recorded as liabilities. We capitalize and amortize costs for internally developed computer software during the application development stage. These costs generally consist of external consulting, internal payroll and payroll-related costs. Our depreciation is based on estimated useful lives (ranging from three We monitor land, building and equipment and software assets for potential impairments. Indicators of potential impairments may include a significant decrease in the fair values of the assets, considerable cost overruns on projects, a change in legal factors or business climate or other factors that indicate that the carrying amount may not be recoverable or useful. There were no recorded land, building and equipment impairments for 2020, 2019 or 2018. Finance Receivables Our leasing subsidiary provides auto and equipment direct financing (leases and loans) to commercial and individual clients. We generally transfer ownership of the property to the client as the terms of the leases expire. Our lease contracts contain bargain purchase options. We account for these leases and loans as sales-type leases. We capitalize and amortize lease or loan origination costs over the life of the financing, using the effective interest method. These costs may include, but are not limited to finder fees, broker fees, filing fees and the cost of credit reports. We record income as other revenues over the financing term using the effective interest method in the consolidated statements of income. An allowance for credit losses on finance receivables is updated and reviewed on a quarterly basis. The allowance, including changes in the amount during 2020, was immaterial to our consolidated financial condition, results of operations and cash flows. Employee Benefit Pension Plan We sponsor a qualified defined benefit pension plan that was modified during 2008. We closed entry into the pension plan, and only participants 40 years of age or older could elect to remain in the plan. Our pension expenses are based on certain actuarial assumptions and also are composed of several components that are determined using the projected unit credit actuarial cost method. Refer to Note 13, Employee Retirement Benefits, for more information about our defined benefit pension plan. Share-Based Compensation We grant qualified and nonqualified share-based compensation under authorized plans. The stock options generally vest on a graded scale over three years following the date of grant and are exercisable over 10-year periods. We grant service-based restricted stock units that cliff vest three years after the date of grant as well as service-based restricted stock units that vest ratably over the three Goodwill and Intangible Assets We recognize goodwill and intangible assets generated through acquisitions within other assets in the consolidated balance sheets. Goodwill arises when the fair value of consideration transferred exceeds the fair value of the net identifiable assets acquired at the acquisition date. Goodwill and intangible assets with an indefinite life are not amortized. Intangible assets with a definite life are amortized on a straight-line basis over the estimated useful lives as follows: broker relationships, 15 years; internally developed technology, five years; value of business acquired, over the remaining coverage period of the underlying insurance contracts, which expired during 2020. We test for impairments on an annual basis or more frequently if events or circumstances indicate that the asset might be impaired. The company performed its annual impairment test on goodwill and intangibles on September 30, which did not result in the recognition of an impairment loss. The company held goodwill of $30 million and intangible assets with an indefinite life of $31 million at December 31, 2020 and 2019, respectively. Subsequent Events There were no subsequent events requiring adjustment to the consolidated financial statements or disclosure. Adopted Accounting Updates ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments In June 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, as well as additional implementation related ASU's in 2018, 2019 and 2020. These ASU’s amend previous guidance on the impairment of financial instruments by adding an impairment model that allows an entity to recognize expected credit losses as an allowance rather than impairing as they are incurred. The new guidance is intended to reduce the complexity of credit impairment models and result in a more timely recognition of expected credit losses. The standards require the company to consider all relevant information at the time of estimating the expected credit loss, including past events, the current environment, and reasonable and supportable forecasts over the life of the asset. These ASU's also eliminated the other-than-temporary impairment model for available for sale fixed-maturity securities by requiring that credit-related impairments be recognized through an allowance account. Changes in the allowance account are recorded in the period of change as a credit loss expense or reversal of credit loss expense. The measurement of credit losses is not impacted, except that credit losses recognized are limited to the amount by which fair value is below amortized cost and that the length of time that a security has been below amortized cost cannot be considered. These ASU's retain the guidance requiring that impaired securities intended to be sold have their amortized cost basis written down to fair value through net income. The company adopted these ASU's on January 1, 2020, and applied them on a modified retrospective basis. As a result of this adoption, an after-tax cumulative effect decrease of $2 million was made to retained earnings representing an increase to the overall valuation allowances for financial instruments measured at amortized cost. These ASU's were applied to available for sale fixed-maturity securities prospectively with no adjustments to the amortized cost basis of securities for which an other-than-temporary impairment had been previously recognized. The company has elected not to measure expected credit losses for accrued interest receivables related to its finance receivables and fixed-maturity securities. Pending Accounting Updates ASU 2018-12, Financial Services - Insurance (Topic 944): Targeted Improvements to the Accounting for Long-Duration Contracts In August 2018, the FASB issued ASU 2018-12, Financial Services - Insurance (Topic 944): Targeted Improvements to the Accounting for Long-Duration Contracts . ASU 2018-12 is intended to improve the timeliness of recognizing changes in the liability for future policy benefits and modify the rate used to discount future cash flows. The ASU will simplify and improve the accounting for certain market-based options or guarantees associated with deposit or account balance contracts and simplify amortization of deferred acquisition costs while improving and expanding required disclosures. In November 2020, the FASB issued an ASU that delayed the effective date of ASU 2018-12 to interim and annual reporting periods beginning after December 15, 2022. These ASU's have not yet been adopted. Management is currently evaluating the impact on our company's consolidated financial condition, results of operations and cash flows.

Investments

Investments	12 Months Ended
	Dec. 31, 2020
Investments [Abstract]
Investments	Investments The following table provides amortized cost, gross unrealized gains, gross unrealized losses and fair value for our fixed-maturity securities: (Dollars in millions) Amortized Gross unrealized Fair At December 31, 2020 gains losses Fixed-maturity securities: Corporate $ 6,281 $ 621 $ 7 $ 6,895 States, municipalities and political subdivisions 4,604 395 2 4,997 Commercial mortgage-backed 271 15 1 285 United States government 115 5 — 120 Foreign government 29 — — 29 Government-sponsored enterprises 12 — — 12 Total $ 11,312 $ 1,036 $ 10 $ 12,338 At December 31, 2019 Fixed-maturity securities: Corporate $ 6,074 $ 332 $ 5 $ 6,401 States, municipalities and political subdivisions 4,477 252 1 4,728 Commercial mortgage-backed 290 11 — 301 United States government 102 2 — 104 Foreign government 28 — — 28 Government-sponsored enterprises 137 — 1 136 Total $ 11,108 $ 597 $ 7 $ 11,698 The net unrealized investment gains in our fixed-maturity portfolio at December 31, 2020, are primarily the result of the continued low interest rate environment that increased the fair value of our fixed-maturity portfolio . Our commercial mortgage-backed securities had an average rating of Aa1/AA at December 31, 2020 and 2019. The table below provides fair values and unrealized losses by investment category and by the duration of the securities’ continuous unrealized loss positions: (Dollars in millions) Less than 12 months 12 months or more Total At December 31, 2020 Fair Unrealized Fair Unrealized Fair Unrealized Fixed-maturity securities: Corporate $ 330 $ 5 $ 46 $ 2 $ 376 $ 7 States, municipalities and political subdivisions 31 2 2 — 33 2 Commercial mortgage-backed 23 1 6 — 29 1 United States government 12 — — — 12 — Foreign government 10 — — — 10 — Total $ 406 $ 8 $ 54 $ 2 $ 460 $ 10 At December 31, 2019 Fixed-maturity securities: Corporate $ 199 $ 2 $ 118 $ 3 $ 317 $ 5 States, municipalities and political subdivisions 98 1 10 — 108 1 Commercial mortgage-backed 6 — — — 6 — United States government — — 4 — 4 — Foreign government 11 — — — 11 — Government-sponsored enterprises 26 1 51 — 77 1 Total $ 340 $ 4 $ 183 $ 3 $ 523 $ 7 Contractual maturity dates for fixed-maturity investments were: (Dollars in millions) Amortized cost Fair % of fair value At December 31, 2020 Maturity dates: Due in one year or less $ 581 $ 589 4.8 % Due after one year through five years 3,450 3,697 30.0 Due after five years through ten years 3,789 4,178 33.9 Due after ten years 3,492 3,874 31.3 Total $ 11,312 $ 12,338 100.0 % Actual maturities may differ from contractual maturities when there is a right to call or prepay obligations with or without call or prepayment penalties. At December 31, 2020 and 2019, the company had fixed-maturity investments with a fair value of $121 million and $117 million, respectively, on deposit with various states in compliance with regulatory requirements. In addition, cash and fixed-maturity investments deposited with third parties used as collateral to secure liabilities on behalf of insureds, cedants and other creditors had a fair value of $98 million and $95 million at December 31, 2020 and 2019, respectively. In the normal course of investing activities, the company enters into investments in limited partnerships, including private equity, real estate investments and asset-backed securities issued by third-parties. The company’s maximum exposure to loss with respect to these investments is limited to the investment carrying values included in the company’s consolidated balance sheets and any unfunded commitments. The following table provides investment income and investment gains and losses: (Dollars in millions) Years ended December 31, 2020 2019 2018 Investment income: Interest $ 455 $ 446 $ 445 Dividends 220 201 181 Other 8 12 5 Total 683 659 631 Less investment expenses 13 13 12 Total $ 670 $ 646 $ 619 Investment gains and losses, net: Equity securities: Investment gains and losses on securities sold, net $ 79 $ 26 $ 9 Unrealized gains and losses on securities still held, net 841 1,626 (404) Subtotal 920 1,652 (395) Fixed-maturity securities: Gross realized gains 16 13 12 Gross realized losses (3) (3) (2) Write-down of impaired securities (78) (9) (5) Subtotal (65) 1 5 Other 10 (3) (12) Total $ 865 $ 1,650 $ (402) The fair value of our equity portfolio was $8.856 billion and $7.752 billion at December 31, 2020 and 2019, respectively. At December 31, 2020 and 2019, Apple, Inc. (Nasdaq:AAPL), an equity holding, was our largest single investment holding with a fair value of $644 million and $414 million, which was 7.5% and 5.5% of our publicly traded common equities portfolio and 3.0% and 2.1% of the total investment portfolio, respectively. During 2020, there were no fixed-maturity securities with an allowance for credit losses. There were 14 fixed-maturity securities that were written down to fair value, due to an intention to be sold, for holdings in the energy, real estate, consumer goods, municipal and technology & electronics sectors. At December 31, 2020 , 128 fixed-maturity investments with a total unrealized loss of $10 million w ere in an unrealized loss position. Of that tota l, no fixed-maturity investments had fair values below 70% of amortized cost. During 2019, we other-than-temporarily impaired three securities. At December 31, 2019, 38 fixed-maturity investments with a total unrealized loss of $3 million had been in an unrealized loss position for 12 months or more. Of that total, no fixed-maturity investments had fair values below 70% of amortized cost.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Fair Value Hierarchy The fair value hierarchy gives the highest priority to quoted prices with readily available independent data in active markets for identical assets or liabilities (Level 1) and the lowest priority to unobservable market inputs (Level 3). When various inputs for measurement fall within different levels of the fair value hierarchy, the lowest observable input that has a significant impact on fair value measurement is used. Our valuation techniques have not changed from those used at December 31, 2019, and ultimately management determines fair value. Financial instruments reported at fair value in our consolidated financial statements are categorized based upon the following characteristics or inputs to the valuation techniques: • Level 1 – Financial assets and liabilities for which inputs are observable and are obtained from reliable quoted prices for identical assets or liabilities in active markets. This is the most reliable fair value measurement and includes, for example, active exchange-traded equity securities. • Level 2 – Financial assets and liabilities for which values are based on quoted prices in markets that are not active or for which values are based on similar assets and liabilities that are actively traded. This also includes pricing models for which the inputs are corroborated by market data. The technique used for the Level 2 fixed-maturity securities is the application of market based modeling. The inputs used for all classes of fixed-maturity securities listed in the table below include relevant market information by asset class, trade activity of like securities, marketplace quotes, benchmark yields, spreads off benchmark yields, interest rates, U.S. Treasury or swap curves, yield to maturity and economic events. Specific to commercial mortgage-backed securities, key inputs also include prepayment and default projections based on past performance of the underlying collateral and current market data. Level 2 fixed-maturity securities are priced by a nationally recognized pricing vendor. The Level 2 nonredeemable preferred equities technique used is the application of market based modeling. The inputs used, similar to those used by the pricing vendor for our fixed-maturity securities, include relevant market information, trade activity of like securities, yield to maturity, corporate action notices and economic events. Level 2 nonredeemable preferred equities are priced by a nationally recognized pricing vendor. • Level 3 – Financial assets and liabilities for which values are based on prices or valuation techniques that require inputs that are both unobservable and significant to the overall fair value measurement. Level 3 inputs include the following: ◦ Quotes from brokers or other external sources that are not considered binding; ◦ Quotes from brokers or other external sources where it cannot be determined that market participants would in fact transact for the asset or liability at the quoted price; or ◦ Quotes from brokers or other external sources where the inputs are not deemed observable. The following tables illustrate the fair value hierarchy for those assets measured at fair value on a recurring basis at December 31, 2020 and 2019. We do not have any liabilities carried at fair value. There were no transfers between Level 1 and Level 2. (Dollars in millions) Quoted prices in Significant At December 31, 2020 Significant other Total Fixed maturities, available for sale: Corporate $ — $ 6,895 $ — $ 6,895 States, municipalities and political subdivisions — 4,997 — 4,997 Commercial mortgage-backed — 285 — 285 United States Government 120 — — 120 Foreign government — 29 — 29 Government-sponsored enterprises — 12 — 12 Subtotal 120 12,218 — 12,338 Common equities 8,541 — — 8,541 Nonredeemable preferred equities — 315 — 315 Separate accounts taxable fixed maturities — 903 — 903 Top Hat savings plan mutual funds and common 51 — — 51 Total $ 8,712 $ 13,436 $ — $ 22,148 At December 31, 2019 Fixed maturities, available for sale: Corporate $ — $ 6,401 $ — $ 6,401 States, municipalities and political subdivisions — 4,728 — 4,728 Commercial mortgage-backed — 301 — 301 United States Government 104 — — 104 Foreign government — 28 — 28 Government-sponsored enterprises — 136 — 136 Subtotal 104 11,594 — 11,698 Common equities 7,518 — — 7,518 Nonredeemable preferred equities — 234 — 234 Separate accounts taxable fixed maturities — 855 — 855 Top Hat savings plan mutual funds and common 45 — — 45 Total $ 7,667 $ 12,683 $ — $ 20,350 We also held Level 1 cash and cash equivalents of $900 million and $767 million at December 31, 2020 and 2019, respectively. Level 3 assets reported at fair value in our consolidated financial statements are not material, and therefore no further disclosures are provided. Fair Value Disclosure for Assets and Liabilities Not Carried at Fair Value The disclosures below are presented to provide information about the effects of current market conditions on financial instruments that are not reported at fair value in our consolidated financial statements. The following table shows fair values of our note payable and long-term debt: (Dollars in millions) Quoted prices in Significant other Significant Total At December 31, 2020 Note payable $ — $ 54 $ — $ 54 6.900% senior debentures, due 2028 — 35 — 35 6.920% senior debentures, due 2028 — 515 — 515 6.125% senior notes, due 2034 — 522 — 522 Total $ — $ 1,126 $ — $ 1,126 At December 31, 2019 Note payable $ — $ 39 $ — $ 39 6.900% senior debentures, due 2028 — 34 — 34 6.920% senior debentures, due 2028 — 506 — 506 6.125% senior notes, due 2034 — 512 — 512 Total $ — $ 1,091 $ — $ 1,091 Fair value of the note payable was determined based upon the outstanding balance at December 31, 2020 and 2019, because it is short term and tied to a variable interest rate. Fair value of the long-term debt was determined under the fair value measurements and disclosure accounting rules based on market pricing of similar debt instruments that are actively trading. We determine fair value for our debt the same way that we value corporate fixed maturities in our investment portfolio. Fair value can vary with macroeconomic conditions. Regardless of the fluctuations in fair value, the outstanding principal amount of our long-term debt is $793 million at both December 31, 2020 and 2019. None of the long-term debt is encumbered by rating triggers. The note payable and long-term debt were classified as Level 2 as an active market does not exist, but fair value is determined based on observable inputs. The following table shows the fair value of our life policy loans, included in other invested assets: (Dollars in millions) Quoted prices in Significant other Significant Total At December 31, 2020 Life policy loans $ — $ — $ 49 $ 49 At December 31, 2019 Life policy loans $ — $ — $ 44 $ 44 Outstanding principal and interest for these life policy loans totaled $33 million and $32 million at December 31, 2020 and 2019, respectively. To determine the fair value, we make the following significant assumptions: (1) the discount rates used to calculate the present value of expected payments are the risk-free spot rates, as nonperformance risk is minimal; and (2) the loan repayment rate by which policyholders pay off their loan balances is in line with past experience. The following table shows fair value of our deferred annuities and structured settlements included in life policy and investment contract reserves: (Dollars in millions) Quoted prices in Significant other Significant Total At December 31, 2020 Deferred annuities $ — $ — $ 836 $ 836 Structured settlements — 227 — 227 Total $ — $ 227 $ 836 $ 1,063 At December 31, 2019 Deferred annuities $ — $ — $ 770 $ 770 Structured settlements — 212 — 212 Total $ — $ 212 $ 770 $ 982 Recorded reserves for the deferred annuities were $761 million and $760 million at December 31, 2020 and 2019, respectively. Recorded reserves for the structured settlements were $145 million and $151 million at December 31, 2020 and 2019, respectively. Fair values for deferred annuities were calculated based upon internally developed models because active markets and observable inputs do not exist. To determine the fair value, we made the following significant assumptions: (1) the discount rates used to calculate the present value of expected payments are the risk-free spot rates plus an A3 rated bond spread for financial issuers at December 31, 2020 and 2019, to account for nonperformance risk; (2) the rate of interest credited to policyholders is the portfolio net earned interest rate less a spread for expenses and profit; and (3) additional lapses occur when the credited interest rate is exceeded by an assumed competitor credited rate, which is a function of the risk-free rate of the economic scenario being modeled. Fair values for structured settlements were calculated based on internally developed models which assume the discount rates used to calculate the present value of expected payments are the risk-free spot rates plus an A3 rated bond spread for financial issuers at December 31, 2020 and 2019, to account for nonperformance risk. The structured settlements were classified as Level 2 as an active market does not exist, but fair value is based on observable inputs.

Property Casualty Loss And Loss

Property Casualty Loss And Loss Expenses	12 Months Ended
	Dec. 31, 2020
Insurance [Abstract]
Property Casualty Loss And Loss Expenses	Property Casualty Loss and Loss Expenses We use actuarial methods, models, assumptions and judgment to estimate, as of a financial statement date, the property casualty loss and loss expense reserves required to pay for and settle all outstanding insured claims, including IBNR claims, as of that date. The actuarial estimate is subject to review and adjustment by an inter-departmental committee that includes actuarial, claims, underwriting, loss prevention and finance management. This committee is familiar with relevant company and industry business, claims and underwriting trends, as well as general economic and legal trends that could affect future loss and loss expense payments. The amount we will actually have to pay for claims can be highly uncertain. This uncertainty, together with the size of our reserves, makes the loss and loss expense reserves our most significant estimate. Our reserving process takes into account known facts and interpretations of circumstances and factors including the type of claim, policy provisions pertaining to each claim, potential subrogation or salvage recoverable, large loss activity and trends, new business activity, judicial decisions, economic conditions, changes in law and regulation and product and underwriting changes. There have been no significant changes in methodologies and assumptions used in calculating loss and loss expense reserves for all years presented. There were no material additional premiums or return premiums accrued for as a result of prior-year effects. Our claims representatives establish case reserves when claims are reported to provide for our unpaid loss and loss expense obligation associated with individual claims. For events designated as natural catastrophes resulting in losses incurred related to direct premiums, we calculate IBNR reserves directly as a result of an estimated claim counts and estimated average dollar amount per claim for each event. Once individual case reserves are established for a catastrophe event, we reduce the IBNR reserves. Our actuarial staff uses generally accepted actuarial methods and models to derive ultimate loss and IBNR reserve estimates. The time interval between a claims occurrence and its settlement is one of the crucial attributes when estimating ultimate losses and IBNR reserves. Due to the uncertainties inherent with loss reserves, our ultimate loss experience could prove better or worse than what our carried reserves reflect. To the extent that reserves are inadequate and are required to be increased, the amount of the increase is a charge in that period, raising our loss and loss expense ratio and reducing earnings. To the extent that reserves are redundant and are required to be released, the amount of the release is a credit in that period, reducing our loss and loss expense ratio and increasing earnings. This table summarizes activity for our consolidated property casualty loss and loss expense reserves: (Dollars in millions) Years ended December 31, 2020 2019 2018 Gross loss and loss expense reserves, January 1 $ 6,088 $ 5,646 $ 5,219 Less reinsurance recoverable 342 238 187 Net loss and loss expense reserves, January 1 5,746 5,408 5,032 Net loss and loss expense reserves related to acquisition of Cincinnati Global at — 246 — Net incurred loss and loss expenses related to: Current accident year 3,968 3,600 3,390 Prior accident years (131) (248) (167) Total incurred 3,837 3,352 3,223 Net paid loss and loss expenses related to: Current accident year 1,493 1,462 1,391 Prior accident years 1,690 1,798 1,456 Total paid 3,183 3,260 2,847 Net loss and loss expense reserves, December 31 6,400 5,746 5,408 Plus reinsurance recoverable 277 342 238 Gross loss and loss expense reserves, December 31 $ 6,677 $ 6,088 $ 5,646 In 2020, 2019 and 2018, the reserve for loss and loss expense in the consolidated balance sheets also included $69 million, $59 million and $61 million, respectively, for certain life and health loss and loss expense reserves. Additional disclosures for reserves related to these health claims are not material and therefore not provided. During 2020, we experienced $131 million of favorable development on prior accident years including $95 million of favorable development in commercial lines, $18 million of favorable development in personal lines and $7 million of unfavorable development in excess and surplus lines. Within commercial lines, we recognized favorable development of $54 million for the commercial casualty line, $39 million for the workers' compensation line and $16 million for the commercial property line due to reduced uncertainty of prior accident year loss and loss expense for these lines. This was partially offset by unfavorable development of $17 million for the commercial auto line. Within personal lines, we recognized favorable reserve development of $15 million in personal auto and $5 million for the homeowner line of business. During 2019, we experienced $248 million of favorable development on prior accident years including $192 million of favorable development in commercial lines, $27 million of favorable development in personal lines and $11 million of favorable development in excess and surplus lines. Within commercial lines, we recognized favorable development of $78 million for the commercial casualty line, $77 million for the workers' compensation line, $25 million for the commercial property line and $6 million for the commercial auto line due to reduced uncertainty of prior accident year loss and loss expense for these lines. Within personal lines, we recognized favorable reserve development of $26 million in personal auto. We recognized unfavorable reserve development of $11 million for the homeowner line of business due primarily to higher-than-anticipated loss development on known claims. During 2018, we experienced $167 million of favorable development on prior accident years including $157 million of favorable development in commercial lines, $13 million of unfavorable development in personal lines, $24 million of favorable development in excess and surplus lines and $1 million of unfavorable development in our reinsurance assumed operations. We recognized favorable development of $58 million for the workers' compensation line and $47 million for both the commercial property line and commercial casualty line due to reduced uncertainty of prior accident year loss and loss expense for these lines. Included in our lines of business are asbestos and environmental claims. We carried $85 million of net loss and loss expense reserves for asbestos and environmental claims at December 31, 2020 and 2019. The asbestos and environmental claims amounts for each respective year constituted less than 2.0% of total net loss and loss expense reserves at these year-end dates. We believe our exposure to asbestos and environmental claims is limited, largely because our reinsurance retention was $500,000 or below prior to 1987. We also were predominantly a personal lines company in the 1960s and 1970s. During the 1980s and early 1990s, commercial lines grew as a percentage of our overall business and our exposure to asbestos and environmental claims grew accordingly. Over that period, we included an asbestos and environmental exclusion in almost all policies or endorsed the exclusion to the policies. We have no exposure to asbestos and environmental claims related to our acquisition of Cincinnati Global. We continue to monitor our claims for evidence of material exposure to other mass tort classes but have found no such credible evidence to date. The following table provides a reconciliation of the property casualty incurred losses and allocated loss adjustment expenses (ALAE) development and paid losses and ALAE development information at December 31, 2020. (Dollars in millions) Cumulative incurred losses Cumulative paid losses and ALAE as reported within the triangles, Liabilities for loss and ALAE for accident years not presented in the triangles, net of reinsurance Total liabilities for loss and ALAE, net of reinsurance Reinsurance recoverable on unpaid losses Total liabilities for gross loss and loss expense reserves Commercial casualty $ 5,179 $ 3,012 $ 91 $ 2,258 $ 24 $ 2,282 Workers' compensation 1,990 1,357 308 941 61 1,002 Commercial auto 2,235 1,581 26 680 5 685 Commercial property 3,158 2,725 15 448 66 514 Personal auto 1,860 1,610 10 260 32 292 Homeowner 1,996 1,781 4 219 18 237 Excess and surplus 836 430 1 407 16 423 Other lines 959 Total liabilities for loss and ALAE reserves 6,394 Unallocated loss adjustment expense reserves 283 Gross loss and loss expense reserves $ 6,677 For all lines of business, the claim counts reported are primarily measured by insurance coverages that are triggered when a loss occurs and a reserve is established. For this purpose, coverages are defined as unique combinations of certain attributes such as line of business and cause of loss. Claims that are opened and closed without payment are included in the reported claim counts. Claim counts are presented on a direct basis only and do not reflect any assumed or ceded reinsurance. In the following tables, commercial casualty, workers' compensation and excess and surplus lines each disclose 10 accident years of loss and ALAE reserves and the cumulative number of reported claims. Commercial auto, commercial property, personal auto and homeowner each disclose five accident years of loss and ALAE reserves and the cumulative number of reported claims as each of these lines have five year cumulative average annual percentage payouts of approximately 95% or higher. Commercial Casualty The following table shows the commercial casualty incurred and paid losses and ALAE development by accident year. The table also shows the IBNR reserves plus expected development on reported losses and claim frequency: (Dollars in millions, reported claims in thousands) As of December 31, 2020 Incurred losses and ALAE, net of reinsurance for the years ended December 31, Total of incurred Cumulative number of Accident Unaudited Year 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2011 $ 466 $ 404 $ 377 $ 377 $ 375 $ 380 $ 366 $ 365 $ 368 $ 361 $ — 19 2012 466 414 417 394 394 404 399 397 397 11 18 2013 448 443 431 416 413 407 391 386 22 20 2014 503 496 479 476 479 465 469 27 21 2015 533 526 529 516 508 502 54 21 2016 563 574 557 555 554 89 21 2017 610 597 577 571 124 21 2018 650 641 622 181 22 2019 672 643 293 19 2020 674 472 11 Total $ 5,179 Cumulative paid losses and ALAE, net of reinsurance 2011 $ 27 $ 93 $ 149 $ 227 $ 266 $ 298 $ 315 $ 325 $ 337 $ 342 2012 27 88 170 232 288 330 346 364 374 2013 35 90 159 232 286 312 337 348 2014 34 97 172 287 338 390 409 2015 38 108 200 287 362 404 2016 46 126 228 331 395 2017 48 122 234 320 2018 44 148 253 2019 39 134 2020 33 Total 3,012 All outstanding liabilities before 2011, net of reinsurance 91 Liabilities for loss and ALAE, net of reinsurance $ 2,258 The following table shows the average annual percentage payout of incurred losses for the commercial casualty line of business: Average annual percentage payout of incurred losses by age, net of reinsurance (unaudited) Years 1 2 3 4 5 6 7 8 9 10 Average annual percentage payout 7.3% 14.9% 17.9% 18.8% 12.7% 9.1% 4.8% 3.5% 3.0% 1.7% Workers’ Compensation The following table shows the workers’ compensation incurred and paid losses and ALAE development by accident year. The table also shows the IBNR reserves plus expected development on reported losses and claim frequency: (Dollars in millions, reported claims in thousands) As of December 31, 2020 Incurred losses and ALAE, net of reinsurance for the years ended December 31, Total of incurred Cumulative number of Accident Unaudited Year 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2011 $ 284 $ 251 $ 246 $ 242 $ 239 $ 236 $ 231 $ 229 $ 228 $ 228 $ 17 24 2012 265 245 234 220 213 211 209 208 207 19 21 2013 264 246 221 212 208 205 202 201 12 20 2014 261 233 214 203 201 198 197 13 19 2015 246 220 208 195 179 173 26 17 2016 230 218 206 188 183 27 16 2017 218 208 190 183 46 15 2018 222 207 199 52 15 2019 224 215 65 14 2020 204 100 10 Total $ 1,990 Cumulative paid losses and ALAE, net of reinsurance 2011 $ 65 $ 131 $ 161 $ 177 $ 186 $ 190 $ 192 $ 195 $ 197 $ 198 2012 62 121 147 162 171 175 178 180 182 2013 61 119 144 157 164 168 170 174 2014 56 110 134 148 157 162 165 2015 47 93 115 129 134 137 2016 46 97 119 131 141 2017 45 88 106 114 2018 48 95 115 2019 49 94 2020 37 Total 1,357 All outstanding liabilities before 2011, net of reinsurance 308 Liabilities for loss and ALAE, net of reinsurance $ 941 The following table shows the average annual percentage payout of incurred losses for the workers’ compensation line of business: Average annual percentage payout of incurred losses by age, net of reinsurance (unaudited) Years 1 2 3 4 5 6 7 8 9 10 Average annual percentage payout 25.9% 26.3% 11.9% 6.7% 4.1% 2.0% 1.4% 1.2% 1.1% 0.5% Commercial Auto The following table shows the commercial auto incurred and paid losses and ALAE development by accident year. The table also shows the IBNR reserves plus expected development on reported losses and claim frequency: (Dollars in millions, reported claims in thousands) As of December 31, 2020 Incurred losses and ALAE, net of reinsurance for the years ended December 31, Total of incurred Cumulative number of reported claims Accident Unaudited Year 2016 2017 2018 2019 2020 2016 $ 417 $ 430 $ 450 $ 463 $ 474 $ 5 53 2017 451 441 443 444 13 51 2018 453 442 442 36 49 2019 452 451 73 46 2020 424 164 33 Total $ 2,235 Cumulative paid losses and ALAE, net of reinsurance 2016 $ 184 $ 273 $ 350 $ 408 $ 441 2017 187 266 334 381 2018 184 266 337 2019 183 268 2020 154 Total 1,581 All outstanding liabilities before 2016, net of reinsurance 26 Liabilities for loss and ALAE, net of reinsurance $ 680 The following table shows the average annual percentage payout of incurred losses for the commercial auto line of business. Commercial auto includes both physical damage and liability losses. A majority of the incurred losses paid after year 2 are the result of liability losses. Average annual percentage payout of incurred losses by age, net of reinsurance (unaudited) Years 1 2 3 4 5 Average annual percentage payout 39.9% 18.6% 15.8% 11.5% 7.0% Commercial Property The following table shows the commercial property incurred and paid losses and ALAE development by accident year. The table also shows the IBNR reserves plus expected development on reported losses and claim frequency: (Dollars in millions, reported claims in thousands) As of December 31, 2020 Incurred losses and ALAE, net of reinsurance for the years ended December 31, Total of incurred Cumulative number of reported claims Accident Unaudited Year 2016 2017 2018 2019 2020 2016 $ 590 $ 551 $ 541 $ 545 $ 542 $ 2 17 2017 587 560 556 565 3 18 2018 630 603 590 7 18 2019 621 606 6 17 2020 855 141 22 Total $ 3,158 Cumulative paid losses and ALAE, net of reinsurance 2016 $ 358 $ 504 $ 528 $ 539 $ 539 2017 395 522 547 560 2018 386 559 576 2019 413 561 2020 489 Total 2,725 All outstanding liabilities before 2016, net of reinsurance 15 Liabilities for loss and ALAE, net of reinsurance $ 448 The following table shows the average annual percentage payout of incurred losses for the commercial property line of business: Average annual percentage payout of incurred losses by age, net of reinsurance (unaudited) Years 1 2 3 4 5 Average annual percentage payout 65.3% 25.8% 3.9% 2.1% 0.1% Personal Auto The following table shows the personal auto incurred and paid losses and ALAE development by accident year. The table also shows the IBNR reserves plus expected development on reported losses and claim frequency: (Dollars in millions, reported claims in thousands) As of December 31, 2020 Incurred losses and ALAE, net of reinsurance for the years ended December 31, Total of incurred Cumulative number of reported claims Accident Unaudited Year 2016 2017 2018 2019 2020 2016 $ 383 $ 384 $ 386 $ 384 $ 384 $ 1 110 2017 412 394 391 393 1 109 2018 424 398 395 1 111 2019 399 383 14 102 2020 305 62 67 Total $ 1,860 Cumulative paid losses and ALAE, net of reinsurance 2016 $ 243 $ 316 $ 351 $ 370 $ 378 2017 256 324 358 374 2018 262 327 358 2019 250 314 2020 186 Total 1,610 All outstanding liabilities before 2016, net of reinsurance 10 Liabilities for loss and ALAE, net of reinsurance $ 260 The following table shows the average annual percentage payout of incurred losses for the personal auto line of business. Personal auto includes both physical damage and liability losses. A majority of the incurred losses paid after year 2 are the result of liability losses. Average annual percentage payout of incurred losses by age, net of reinsurance (unaudited) Years 1 2 3 4 5 Average annual percentage payout 64.2% 17.3% 8.6% 4.6% 2.0% Homeowner The following table shows the homeowner incurred and paid losses and ALAE development by accident year. The table also shows the IBNR reserves plus expected development on reported losses and claim frequency: (Dollars in millions, reported claims in thousands) As of December 31, 2020 Incurred losses and ALAE, net of reinsurance for the years ended December 31, Total of incurred Cumulative number of reported claims Accident Unaudited Year 2016 2017 2018 2019 2020 2016 $ 315 $ 304 $ 303 $ 302 $ 304 $ — 23 2017 356 383 385 387 — 26 2018 370 386 387 5 24 2019 432 421 10 22 2020 497 54 21 Total $ 1,996 Cumulative paid losses and ALAE, net of reinsurance 2016 $ 208 $ 283 $ 295 $ 299 $ 302 2017 277 356 378 384 2018 268 368 378 2019 303 391 2020 326 Total 1,781 All outstanding liabilities before 2016, net of reinsurance 4 Liabilities for loss and ALAE, net of reinsurance $ 219 The following table shows the average annual percentage payout of incurred losses for the homeowner line of business: Average annual percentage payout of incurred losses by age, net of reinsurance (unaudited) Years 1 2 3 4 5 Average annual percentage payout 69.3% 23.0% 4.1% 1.4% 0.8% Excess and Surplus Lines The following table shows the excess and surplus lines incurred and paid losses and ALAE development by accident year. The table also shows the IBNR reserves plus expected development on reported losses and claim frequency: (Dollars in millions, reported claims in thousands) As of December 31, 2020 Incurred losses and ALAE, net of reinsurance for the years ended December 31, Total of incurred Cumulative number of reported claims Accident Unaudited Year 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2011 $ 48 $ 47 $ 44 $ 38 $ 36 $ 35 $ 35 $ 34 $ 34 $ 34 $ — 1 2012 67 56 49 40 37 36 35 36 35 — 1 2013 74 64 54 45 42 41 41 41 2 2 2014 95 82 75 64 60 59 59 5 2 2015 96 81 73 67 65 66 6 2 2016 93 87 84 82 90 13 3 2017 104 95 95 94 15 3 2018 116 109 110 29 3 2019 137 135 50 3 2020 172 $ 105 2 Total $ 836 Cumulative paid losses and ALAE, net of reinsurance 2011 $ 8 $ 14 $ 23 $ 27 $ 30 $ 32 $ 34 $ 33 $ 33 $ 33 2012 9 15 19 25 29 31 32 33 34 2013 7 12 20 27 32 34 37 39 2014 9 17 27 37 43 48 51 2015 8 19 29 41 51 54 2016 10 21 39 51 62 2017 11 23 41 57 2018 11 26 50 2019 13 34 2020 16 Total 430 All outstanding liabilities before 2011, net of reinsurance 1 Liabilities for loss and ALAE, net of reinsurance $ 407 The following table shows the average annual percentage payout of incurred losses for the excess and surplus lines insurance segment. Excess and surplus lines consist mostly of commercial casualty and commercial property coverages. A majority of the incurred losses paid after year 2 are the result of commercial casualty losses. Average annual percentage payout of incurred losses by age, net of reinsurance (unaudited) Years 1 2 3 4 5 6 7 8 9 10 Average annual percentage payout 14.6% 14.4% 19.2% 15.4% 11.7% 6.9% 3.9% 2.2% 1.0% 0.2%

Life Policy And Investment Cont

Life Policy And Investment Contract Reserves	12 Months Ended
	Dec. 31, 2020
Liability for Future Policy Benefit, before Reinsurance [Abstract]
Life Policy And Investment Contract Reserves	Life Policy and Investment Contract Reserves We establish the reserves for traditional life insurance policies based on expected expenses, mortality, morbidity, withdrawal rates, timing of claim presentation and investment yields, including a provision for uncertainty. Once these assumptions are established, they generally are maintained throughout the lives of the contracts. We use both our own experience and industry experience, adjusted for historical trends, in arriving at our assumptions for expected mortality, morbidity and withdrawal rates as well as for expected expenses. We base our assumptions for expected investment income on our own experience adjusted for current and future economic conditions. We establish reserves for the company’s universal life, deferred annuity and structured settlement policies equal to the cumulative account balances, which include premium deposits plus credited interest less charges and withdrawals. Some of our universal life policies contain no-lapse guarantee provisions. For these policies, we establish a reserve in addition to the account balance, based on expected no-lapse guarantee benefits and expected policy assessments. This table summarizes our life policy and investment contract reserves: (Dollars in millions) At December 31, 2020 2019 Life policy reserves: Ordinary/traditional life $ 1,301 $ 1,226 Other 52 50 Subtotal 1,353 1,276 Investment contract reserves: Deferred annuities 761 760 Universal life 647 640 Structured settlements 145 151 Other 9 8 Subtotal 1,562 1,559 Total life policy and investment contract reserves $ 2,915 $ 2,835

Deferred Policy Acquisition Cos

Deferred Policy Acquisition Costs	12 Months Ended
	Dec. 31, 2020
Deferred Costs [Abstract]
Deferred Policy Acquisition Costs	Deferred Policy Acquisition Costs Expenses directly related to successfully acquired insurance policies – primarily commissions, premium taxes and underwriting costs – are deferred and amortized over the terms of the policies. We update our acquisition cost assumptions periodically to reflect actual experience, and we evaluate the costs for recoverability. The table below shows the deferred policy acquisition costs and asset reconciliation: (Dollars in millions) Years ended December 31, 2020 2019 2018 Property casualty: Deferred policy acquisition costs asset, January 1 $ 512 $ 464 $ 438 Capitalized deferred policy acquisition costs 1,087 1,034 933 Amortized deferred policy acquisition costs (1,057) (986) (907) Deferred policy acquisition costs asset, December 31 $ 542 $ 512 $ 464 Life: Deferred policy acquisition costs asset, January 1 $ 262 $ 274 $ 232 Capitalized deferred policy acquisition costs 58 61 60 Amortized deferred policy acquisition costs (49) (48) (39) Shadow deferred policy acquisition costs (8) (25) 21 Deferred policy acquisition costs asset, December 31 $ 263 $ 262 $ 274 Consolidated: Deferred policy acquisition costs asset, January 1 $ 774 $ 738 $ 670 Capitalized deferred policy acquisition costs 1,145 1,095 993 Amortized deferred policy acquisition costs (1,106) (1,034) (946) Shadow deferred policy acquisition costs (8) (25) 21 Deferred policy acquisition costs asset, December 31 $ 805 $ 774 $ 738 No premium deficiencies were recorded in the consolidated statements of income in 2020, 2019 and 2018, as the sum of the anticipated loss and loss expenses, policyholder dividends and unamortized deferred acquisition expenses did not exceed the related unearned premiums and anticipated investment income.

Note Payable

Note Payable	12 Months Ended
	Dec. 31, 2020
Notes Payable, Current [Abstract]
Note Payable	Note Payable We have one unsecured revolving credit facility through multiple commercial banks which was due to expire on February 4, 2025, with the option of a one-year extension remaining from the 2019 amendment. The borrowing capacity is $300 million with an additional $300 million accordion feature. Terms and conditions of the agreement include a debt-to-total capital maximum of 35%. On December 11, 2020, we exercised our option to extend the term of the line of credit one year to February 4, 2026. We had no compensating balance requirements on short-term debt for either 2020 or 2019. At December 31, 2020 and 2019, $54 million and $39 million was drawn on the line of credit, respectively. The interest rate charged on our borrowings on this credit agreement ranged from 1.03% to 4.25% during 2020 and ranged from 2.59% to 3.41% during 2019. In addition, we have letters of credit related to our Cincinnati Re and Cincinnati Global operations with no amounts drawn at December 31, 2020 and 2019.

Long-Term Debt And Lease Obliga

Long-Term Debt And Lease Obligation	12 Months Ended
	Dec. 31, 2020
Long-term Debt and Lease Obligation [Abstract]
Long-Term Debt And Capital Lease Obligation	Long-Term Debt and Lease Obligations This table summarizes the principal amounts of our long-term debt excluding unamortized discounts, none of which are encumbered by rating triggers: (Dollars in millions) Book value Principal amount Interest rate Year of At December 31, At December 31, 2020 2019 2020 2019 6.900% 1998 Senior debentures, due 2028 $ 27 $ 27 $ 28 $ 28 6.920% 2005 Senior debentures, due 2028 391 391 391 391 6.125% 2004 Senior notes, due 2034 370 370 374 374 Total $ 788 $ 788 $ 793 $ 793 The finance lease term for equipment and autos is three $3 million of interest for finance and operating leases: (Dollars in millions) Years ended December 31, 2021 2022 2023 2024 2025 2026 and thereafter Finance lease obligations $ 15 $ 12 $ 10 $ 6 $ 4 $ 2 Operating lease obligations 2 2 2 2 1 2 Total lease obligations $ 17 $ 14 $ 12 $ 8 $ 5 $ 4 The following table provides lease cost and other information for the year ended December 31, 2020 and 2019: (Dollars in millions) 2020 2019 Lease cost: Finance lease cost $ 15 $ 9 Operating lease cost 4 4 Total lease cost $ 19 $ 13 Other information finance leases: Finance cash outflows $ 15 $ 15 Weighted average discount rate 2.62 % 2.96 % Weighted average remaining lease term in years 3.67 3.65 Other information operating leases: Operating cash outflows $ 8 $ 8 Weighted average discount rate 3.65 % 3.69 % Weighted average remaining lease term in years 4.84 4.71

Shareholders' Equity And Divide

Shareholders' Equity And Dividend Restrictions	12 Months Ended
	Dec. 31, 2020
Shareholders Equity And Dividend Restrictions [Abstract]
Shareholders' Equity And Dividend Restrictions	Shareholders’ Equity and Dividend Restrictions Declared cash dividends per share were $2.40 , $2.24 and $2.12 for the years ended December 31, 2020, 2019 and 2018, respectively. Our lead insurance subsidiary, The Cincinnati Insurance Company, paid dividends to the parent company of $550 million in 2020, $625 million in 2019 and $500 million in 2018. State regulatory requirements restrict the dividends insurance subsidiaries can pay. Generally, the most our lead insurance subsidiary can pay without prior regulatory approval is the greater of 10% of statutory capital and surplus or 100% of statutory net income for the prior calendar year. Dividends exceeding these limitations may be paid only with approval of the insurance department of the domiciliary state. During 2021, the total that our lead insurance subsidiary may pay in dividends is approximately $583 million. Dividend payments from Cincinnati Global to the parent company are subject to regulation by U.K. law. Cincinnati Global paid no dividends to the parent company in either 2020 or 2019. Accumulated Other Comprehensive Income The table below shows beginning and end of year accumulated other comprehensive income (AOCI) for investments, pension obligations, life deferred acquisition costs, life policy reserves and other. The changes from the beginning of year to the end of year are the result of changes to other comprehensive income or loss (OCI). (Dollars in millions) 2020 2019 2018 Before Income Net Before Income Net Before Income Net Investments: AOCI, January 1 $ 590 $ 123 $ 467 $ 46 $ 9 $ 37 $ 3,540 $ 733 $ 2,807 Cumulative effect of change in accounting for equity securities as of January 1, 2018 — — — — — — (3,155) (652) (2,503) Adjusted AOCI, beginning of period 590 123 467 46 9 37 385 81 304 OCI before investment gains and losses, net, recognized in net income 371 78 293 545 115 430 (334) (71) (263) Investment gains and losses, net, recognized in net income 65 14 51 (1) (1) — (5) (1) (4) OCI 436 92 344 544 114 430 (339) (72) (267) AOCI, December 31 $ 1,026 $ 215 $ 811 $ 590 $ 123 $ 467 $ 46 $ 9 $ 37 Pension obligations: AOCI, January 1 $ (9) $ — $ (9) $ (16) $ (2) $ (14) $ (12) $ (1) $ (11) OCI excluding amortization recognized in net income (35) (7) (28) 6 2 4 (5) (1) (4) Amortization recognized in net income 3 — 3 1 — 1 1 — 1 OCI (32) (7) (25) 7 2 5 (4) (1) (3) AOCI, December 31 $ (41) $ (7) $ (34) $ (9) $ — $ (9) $ (16) $ (2) $ (14) Life deferred acquisition costs, life policy reserves and other: AOCI, January 1 $ (13) $ (3) $ (10) $ (1) $ — $ (1) $ (10) $ (2) $ (8) OCI before investment gains and losses, net, recognized in net income 3 1 2 (15) (3) (12) (3) (1) (2) Investment gains and losses, net, recognized in net income — — — 3 — 3 12 3 9 OCI 3 1 2 (12) (3) (9) 9 2 7 AOCI, December 31 $ (10) $ (2) $ (8) $ (13) $ (3) $ (10) $ (1) $ — $ (1) Summary of AOCI: AOCI, January 1 $ 568 $ 120 $ 448 $ 29 $ 7 $ 22 $ 3,518 $ 730 $ 2,788 Cumulative effect of change in accounting for equity securities as of January 1, 2018 — — — — — — (3,155) (652) (2,503) Adjusted AOCI, beginning of period 568 120 448 29 7 22 363 78 285 Investments OCI 436 92 344 544 114 430 (339) (72) (267) Pension obligations OCI (32) (7) (25) 7 2 5 (4) (1) (3) Life deferred acquisition costs, life policy reserves and other OCI 3 1 2 (12) (3) (9) 9 2 7 Total OCI 407 86 321 539 113 426 (334) (71) (263) AOCI, December 31 $ 975 $ 206 $ 769 $ 568 $ 120 $ 448 $ 29 $ 7 $ 22 Investments gains and losses, net, and life deferred acquisition costs, life policy reserves and other investment gains and losses, net, are recorded in the investment gains and losses, net, line item in the consolidated statements of income. Amortization on pension obligations is recorded in the insurance losses and contract holders' benefits and underwriting, acquisition and insurance expenses line items in the consolidated statements of income.

Reinsurance

Reinsurance	12 Months Ended
	Dec. 31, 2020
Reinsurance Disclosures [Abstract]
Reinsurance	Reinsurance Primary components of our property casualty reinsurance assumed operations include involuntary and voluntary assumed as well as contracts from our reinsurance assumed operations, known as Cincinnati Re. Primary components of our ceded reinsurance include a property per risk treaty, property excess treaty, casualty per occurrence treaty, casualty excess treaty, property catastrophe treaty and catastrophe bonds and retrocessions on our reinsurance assumed operations. Management’s decisions about the appropriate level of risk retention are affected by various factors, including changes in our underwriting practices, capacity to retain risks and reinsurance market conditions. The table below summarizes our consolidated property casualty insurance net written premiums, earned premiums and incurred loss and loss expenses: (Dollars in millions) Years ended December 31, 2020 2019 2018 Direct written premiums $ 5,756 $ 5,477 $ 5,018 Assumed written premiums 335 244 173 Ceded written premiums (227) (205) (161) Net written premiums $ 5,864 $ 5,516 $ 5,030 Direct earned premiums $ 5,623 $ 5,340 $ 4,931 Assumed earned premiums 285 199 149 Ceded earned premiums (217) (205) (160) Earned premiums $ 5,691 $ 5,334 $ 4,920 Direct incurred loss and loss expenses $ 3,699 $ 3,402 $ 3,188 Assumed incurred loss and loss expenses 184 117 125 Ceded incurred loss and loss expenses (46) (167) (90) Incurred loss and loss expenses $ 3,837 $ 3,352 $ 3,223 Our life insurance company purchases reinsurance for protection of a portion of risks that are written. Primary components of our life reinsurance program include individual mortality coverage, aggregate catastrophe and accidental death coverage in excess of certain deductibles. The table below summarizes our consolidated life insurance earned premiums and contract holders' benefits incurred: (Dollars in millions) Years ended December 31, 2020 2019 2018 Direct earned premiums $ 362 $ 341 $ 320 Ceded earned premiums (73) (71) (70) Earned premiums $ 289 $ 270 $ 250 Direct contract holders' benefits incurred $ 359 $ 359 $ 328 Ceded contract holders' benefits incurred (62) (73) (61) Contract holders' benefits incurred $ 297 $ 286 $ 267 The ceded benefits incurred can vary depending on the type of life insurance policy held and the year the policy was issued.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The significant components of deferred tax assets and liabilities included in the consolidated balance sheets at December 31 were as follows: (Dollars in millions) At December 31, 2020 2019 Deferred tax assets: Unearned premiums $ 119 $ 113 Loss and loss expense reserves 81 66 Deferred international earnings 45 51 Net operating loss on international earnings 26 4 Other 41 39 Deferred tax assets before valuation allowance 312 273 Valuation allowance for international operations 56 41 Deferred tax assets net of valuation allowance 256 232 Deferred tax liabilities: Investment gains and other, net 1,240 995 Deferred acquisition costs 143 139 Life policy reserves 121 120 Investments 13 23 Other 38 34 Total gross deferred tax liabilities 1,555 1,311 Net deferred income tax liability $ 1,299 $ 1,079 Deferred tax assets and liabilities reflect temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amount recognized for tax purposes. Deferred tax assets are reduced by a valuation allowance when management believes it is more likely than not that some, or all, of the deferred tax assets will not be realized. After considering all positive and negative evidence of taxable income in the carryback and carryforward periods as permitted by law, we believe it is more likely than not that all of the deferred tax assets on our U.S. domestic operations will be realized. As a result, we have no valuation allowance as of December 31, 2020 and 2019 for our U.S. domestic operations. As more fully discussed below, we do carry a valuation allowance on the deferred tax assets related to Cincinnati Global. For financial reporting purposes, income (loss) before income taxes includes the following components: (Dollars in millions) For the years ended December 31, 2020 2019 2018 United States $ 1,521 $ 2,440 $ 251 International (22) 32 — Total income before income taxes $ 1,499 $ 2,472 $ 251 The provision (benefit) for income taxes consists of: (Dollars in millions) For the years ended December 31, 2020 2019 2018 Provision (benefit) for income taxes: Current – United States federal $ 147 $ 137 $ 11 International — (5) — Total current 147 132 11 Deferred – United States federal 136 338 (47) International — 5 — Total deferred 136 343 (47) Total provision (benefit) for income taxes $ 283 $ 475 $ (36) The differences between the 21% statutory federal income tax rate and our effective income tax rate were as follows: (Dollars in millions) Years ended December 31, 2020 2019 2018 Tax at statutory rate: $ 315 21.0 % $ 519 21.0 % $ 53 21.0 % Increase (decrease) resulting from: Tax-exempt income from municipal bonds (20) (1.3) (19) (0.8) (20) (8.0) Dividend received exclusion (17) (1.1) (16) (0.6) (15) (6.0) Tax accounting method changes — — — — (50) (19.9) Other 5 0.3 (9) (0.4) (4) (1.4) Provision (benefit) for income taxes $ 283 18.9 % $ 475 19.2 % $ (36) (14.3) % In 2018, we received approval from the IRS to change our method of tax accounting for certain items applicable for the 2017 tax year and tax return, primarily related to the valuation of our tax basis unpaid losses. Accounting guidance does not allow recognition of the impact of certain tax accounting method changes until approved by the IRS. As a result, we recognized a $50 million income tax benefit in 2018 for the difference between the current 21% tax rate and the 2017 tax rate of 35% for the related items. This reduced our effective tax rate by 19.9% for the year ended December 31, 2018. The provision for federal income taxes is based upon the filing of a consolidated income tax return for the company and its domestic subsidiaries within the United States. As of December 31, 2020, 2019 and 2018, we have no operating loss carryforwards in the United States. For the years ended December 31, 2020, 2019 and 2018, we have no capital loss carryforwards in the United States. As more fully discussed below, Cincinnati Global, has operating loss carryforwards in the United Kingdom. As more fully discussed in Note 1, Summary of Significant Accounting Policies, COVID-19 was declared a pandemic on March 11, 2020. In response to the pandemic, various stimulus legislation was enacted in 2020 including the Coronavirus Aid, Relief and Economic Security Act (CARES Act), signed into law on March 27, 2020 and the Consolidated Appropriations Act, 2021 (CAA Act), signed into law on December 27, 2020. We have evaluated both Acts as well as other pandemic-related legislation enacted in 2020 and believe any impact to our financial statements, as a result of such legislation, will be immaterial. Unrecognized Tax Benefits As of December 31, 2020, 2019 and 2018, we had a gross unrecognized tax benefit of $34 million . The following is a tabular reconciliation of the total amounts of unrecognized tax benefits. (Dollars in millions) Years ended December 31, 2020 2019 2018 Gross unrecognized tax benefits, January 1 $ 34 $ 34 $ — Gross increase in prior year positions — — — Gross decrease in prior year positions — — — Gross increase in current year positions — — 34 Settlements with tax authorities — — — Lapse of statute of limitations — — — Gross unrecognized tax benefits, December 31 $ 34 $ 34 $ 34 The unrecognized tax benefit liability is carried in other liabilities in the consolidated balance sheets. Included in the unrecognized tax benefit liability as of December 31, 2020 is $34 million that, if recognized, would affect the effective tax ra te in the period of the release. Although no interest and penalties currently are accrued, if incurred, they would be recognized as a component of income tax expense. We do not expect any changes to our unrecognized tax benefit liability in the next twelve months. The statute of limitations for federal tax purposes has generally closed for tax years ended December 31, 2016 and earlier, however, as a result of certain net operating loss carryback claims we have filed, the IRS maintains a limited ability to assess tax for the 2015 tax year. In 2019, the IRS began its examination of the tax year ended December 31, 2017 and they have expanded their scope to include tax year ended December 31, 2018. At this time, no adjustments have been proposed. In addition to our IRS filings, we file income tax returns with immaterial amounts in various state jurisdictions and record these amounts in our provision for income taxes for both current and deferred taxes. The statute of limitations for state income tax purposes has closed for tax years ended December 31, 2016 and earlier. Cincinnati Global operates in the United Kingdom and as such, is subject to tax in that jurisdiction. The statute of limitation for tax return review by Her Majesty’s Revenue and Customs (HMRC) has closed for tax years ended December 31, 2018 and earlier. There are currently no tax returns under review by HMRC. Income taxes paid in our consolidated statements of cash flows are shown net of refunds received. We received no refunds in 2020, $94 million in 2019 and none in 2018. Cincinnati Global Cincinnati Global's operating results for the year ended December 31, 2020, increased their net deferred assets by $15 million with an offsetting increase of $15 million to their valuation allowance. As of December 31, 2020, Cincinnati Global had a net deferred tax asset of $56 million and an offsetting valuation allowance of $56 million. Deferred tax assets are reduced by a valuation allowance when management believes it is more likely than not that some, or all, of the deferred tax assets will not be realized. After considering all positive and negative evidence, including cumulative losses related to the operations of Cincinnati Global, we believe it was appropriate to set up a valuation allowance for purposes of our opening Cincinnati Global balance sheet and is appropriate to carry a valuation allowance as of December 31, 2020 and 2019. The following is a tabular reconciliation of the total amounts of our Cincinnati Global valuation allowance. (Dollars in millions) Years ended December 31, 2020 2019 Valuation allowance, January 1 $ 41 $ — Acquisition accounting amount — 55 Current year operations 15 (14) Valuation allowance, December 31 $ 56 $ 41 As of December 31, 2020, and 2019, Cincinnati Global had operating loss carryforwards in the United States of $26 million and $20 million and in the United Kingdom of $108 million and $127 million , respectively. These Cincinnati Global losses can only be utilized within the Cincinnati Global group in both the United States and in the United Kingdom and cannot offset the income of our CFC group domestic operations in the United States.

Net Income Per Common Share

Net Income Per Common Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Net Income Per Common Share	Net Income Per Common Share Basic earnings per share are computed based on the weighted average number of common shares outstanding. Diluted earnings per share are computed based on the weighted average number of common and dilutive potential common shares outstanding using the treasury stock method. The table shows calculations for basic and diluted earnings per share: (In millions, except per share data) Years ended December 31, 2020 2019 2018 Numerator: Net income—basic and diluted $ 1,216 $ 1,997 $ 287 Denominator: Basic weighted-average common shares outstanding 161.2 163.2 163.2 Effect of share-based awards: Stock options 0.7 1.2 0.8 Nonvested shares 0.5 0.7 0.5 Diluted weighted-average shares 162.4 165.1 164.5 Earnings per share: Basic $ 7.55 $ 12.24 $ 1.76 Diluted 7.49 12.10 1.75 Number of anti-dilutive share-based awards 1.4 — 1.3

Employee Retirement Benefits

Employee Retirement Benefits	12 Months Ended
	Dec. 31, 2020
Retirement Benefits [Abstract]
Employee Retirement Benefits	Employee Retirement Benefits We sponsor a qualified defined benefit pension plan that we closed entry into for new associates as of June 30, 2008, and only participants 40 years of age or older as of August 31, 2008, could elect to continue to participate. During 2008, we changed the form of retirement benefit we offer some associates to a company match on contributions to a 401(k) plan as further explained below. For participants remaining in the pension plan, we continue to fund future benefit obligations. Benefits for the defined benefit pension plan are based on years of credited service and compensation level. Contributions are based on the prescribed method defined in the Pension Protection Act. Our net periodic benefit cost is based on certain actuarial assumptions and also is composed of several components that are determined using the projected unit credit actuarial cost method. The qualified plan has been amended to allow for distribution of vested balances to terminated participants. We sponsor a defined contribution plan (401(k) plan) for eligible associates with matching company contributions totaling $22 million, $19 million and $18 million during the years 2020, 2019 and 2018, respectively. Associates who are not accruing benefits under the pension plan are eligible to receive the company match of up to 6% of cash compensation. Participants vest in the company match for the 401(k) plan after three years of eligible service. We maintain a supplemental executive retirement plan (SERP) with a benefit obligation of $10 million at year-end 2020 and $11 million at year-end 2019, which is included in the projected benefit obligation. The company also makes available to a select group of associates the CFC Top Hat Savings Plan, a nonqualified deferred compensation plan, which had a fair value of $51 million and $45 million at December 31, 2020 and 2019, respectively. Company matching contributions to the CFC Top Hat Savings Plan totaled approximately $1 million for the years 2020, 2019 and 2018, respectively. Defined Benefit Pension Plan Assumptions We evaluate our pension plan assumptions annually and update them as necessary. This is a summary of the weighted-average assumptions used to determine our benefit obligations at December 31 for the plans: Qualified Pension Plan SERP 2020 2019 2020 2019 Discount rate 2.68 % 3.40 % 2.52 % 3.33 % Rate of compensation increase 2.25-3.25 2.25-3.25 2.25-3.25 2.25-3.25 To determine the discount rate for each plan, a theoretical settlement portfolio of high-quality rated corporate bonds was chosen to provide payments approximately matching the plan’s projected benefit payments. A single interest rate for each plan was determined resulting in a discounted value of the plan's benefit payments that equates to the market value of the selected bonds. The discount rate is reflective of current market interest rate conditions and our plan's liability characteristics. Based on this analysis, we decreased the rate from the prior year by 0.72 percentage points for the qualified pension plan and by 0.81 percentage points for the SERP. Compensation increase assumptions reflect anticipated rates of inflation, real return on wage growth and merit and promotional increases. The mortality assumption is updated annually to reflect the updated scale. The Pri-2012 tables with Scale MP-2020 and Scale MP-2019 were used for the years 2020 and 2019, respectively. The RP-2014 table projected generationally with Scale MP-2018 was used for the year 2018. The updated mortality table did not have a significant impact on our consolidated financial statements as our qualified plan assumes the majority of benefits will be paid in the form of lump sums. This is a summary of the weighted-average assumptions used to determine our net periodic benefit cost for the plans: Qualified Pension Plan SERP 2020 2019 2018 2020 2019 2018 Discount rate 3.40 % 4.34 % 3.73 % 3.33 % 4.25 % 3.61 % Expected return on plan assets 7.00 7.00 7.25 n/a n/a n/a Rate of compensation increase 2.25-3.25 2.25-3.25 2.75-3.25 2.25-3.25 2.25-3.25 2.75-3.25 The discount rate was decreased by 0.94 percentage points for the qualified pension plan and 0.92 percentage points for the SERP due to market interest rate conditions at the beginning of 2020. The discount rate assumptions for our benefit obligation generally track with high-quality rated corporate bond yields chosen in our theoretical settlement portfolio, and yearly adjustments reflect any changes to those bond yields. We believe the expected return on plan assets is representative of the expected long-term rate of return on these assets, which is consistent with 2020 expectations of interest rates and based partially on the fact that the plan’s common stock holdings pay dividends. We review historical actual return on plan assets when determining our expected long-term rate of return. Total portfolio return for 2020 was 11.4% and for 2019 was 24.5%. Our compensation increase assumptions in 2020 reflect anticipated rates of inflation, real return on wage growth and merit and promotional increases. Benefit obligation activity using an actuarial measurement date for our qualified pension plan and SERP at December 31 follows: (Dollars in millions) At December 31, 2020 2019 Change in projected benefit obligation: Benefit obligation, January 1 $ 350 $ 318 Service cost 9 8 Interest cost 12 13 Actuarial loss 51 45 Benefits paid (35) (34) Projected benefit obligation, December 31 $ 387 $ 350 Change in plan assets: Fair value of plan assets, January 1 $ 354 $ 318 Actual return on plan assets 34 70 Employer contribution 4 — Benefits paid (35) (34) Fair value of plan assets, December 31 $ 357 $ 354 Funded status, December 31 $ (30) $ 4 Accumulated benefit obligation $ 360 $ 327 Our plan was in an unfunded status for 2020 compared to 2019 primarily due to lower year over year return on plan assets, increases in actuarial losses from decreases in discount rates and changes to assumed lump sum basis. The lump sum basis was changed from a Pension Benefit Guaranty Corporation (PBGC) rate, which is no longer being published by the PBGC after December 31, 2020, and mortality rates based on GAM83 tables with minor adjustments, to Internal Revenue Code (IRC) Section 417(e) interest rates and IRC Section 417(e) mortality rates, updated annually and projected into the future. The lump sum basis change resulted in an increase to our actuarial loss at December 31, 2020. A reconciliation follows of the funded status for our qualified plan and SERP at the end of the measurement period to the amounts recognized in the consolidated balance sheets at December 31: (Dollars in millions) At December 31, 2020 2019 Pension amounts recognized in the consolidated balance sheets: Other (liability) assets $ (30) $ 4 Total $ (30) $ 4 Pension amounts recognized in accumulated other comprehensive income: Net actuarial loss $ 41 $ 9 Total $ 41 $ 9 Below are the components of our net periodic benefit cost, as well as other changes in plan assets and benefit obligations recognized in other comprehensive income for our qualified plan and SERP at December 31: (Dollars in millions) Years ended December 31, 2020 2019 2018 Net periodic benefit cost: Service cost $ 9 $ 8 $ 11 Non-service costs (benefit): Interest cost 12 13 13 Expected return on plan assets (21) (20) (22) Amortization of actuarial loss and prior service cost 3 1 1 Other 3 1 2 Net periodic benefit cost $ 6 $ 3 $ 5 Other changes in plan assets and benefit obligations recognized in other Current year actuarial (gain) loss $ 38 $ (5) $ 7 Amortization of actuarial loss (6) (2) (3) Total recognized in other comprehensive (income) loss $ 32 $ (7) $ 4 Total recognized in net periodic benefit cost and other comprehensive $ 38 $ (4) $ 9 The 2020 change in the amount recognized in other comprehensive income from 2019 is largely due to changes in the actuarial loss resulting from decreases in discount rates and changes to assumed lump sum basis as discussed above. Service costs and non-service costs (benefit) are allocated in the same proportion primarily to underwriting, acquisition and insurance expenses line item with the remainder allocated to the insurance losses and contract holders' benefits line item on the consolidated statements of income for 2020, 2019 and 2018. Defined Benefit Pension Plan Assets The pension plan assets are managed to maximize total return over the long term while providing sufficient liquidity and current return to satisfy the cash flow requirements of the plan. The plan’s day-to-day investment decisions are managed by our internal investment department; however, overall investment strategies are discussed with our employee benefits committee. Our investment strategy is to weight our portfolio towards large-cap, high-quality, dividend-growing equities that we have historically favored. As our plan matures and interest rates normalize, we expect a greater allocation to fixed-income securities to better align asset and liability market risks. Our fixed-maturity bond portfolio is investment grade. The plan does not engage in derivative transactions. Excluding cash, during 2020 we held approximately 82% of our pension portfolio in domestic common equity investments. The remainder of the portfolio consisted of 9% in United States government fixed-maturity investments, 6% in domestic corporate fixed-maturity investments and 3% in states, municipalities and taxable political subdivisions fixed-maturity investments. Our common equity portfolio consisted of 26% in the information technology sector, 20% in the financial sector, 13% in the industrial sector, and 12% in the healthcare sector at year-end 2020. No additional sectors accounted for 10% or more of our common equity portfolio balance at year-end 2020. Investments in securities are valued based on the fair value hierarchy outlined in Note 3, Fair Value Measurements. The pension plan did not have any liabilities carried at fair value during the years ended December 31, 2020 and 2019. There have been no transfers between Level 1 and Level 2 for the years ended December 31, 2020 and 2019. The following table shows the fair value hierarchy for those assets measured at fair value on a recurring basis at December 31, 2020 and 2019. Excluded from the table below is cash on hand of $31 million and $17 million at December 31, 2020 and 2019, respectively. (Dollars in millions) Quoted prices in Significant other Significant Total At December 31, 2020 Fixed maturities, available for sale: United States Government $ 31 $ — $ — $ 31 Corporate — 20 — 20 States, municipalities and political subdivisions — 9 — 9 Total fixed maturities, available for sale 31 29 — 60 Common equities 266 — — 266 Total $ 297 $ 29 $ — $ 326 At December 31, 2019 Fixed maturities, available for sale: United States Government $ 25 $ — $ — $ 25 Corporate — 27 — 27 States, municipalities and political subdivisions — 25 — 25 Total fixed maturities, available for sale 25 52 — 77 Common equities 260 — — 260 Total $ 285 $ 52 $ — $ 337 Our pension plan assets included 202,337 and 232,113 shares of the company’s common stock at December 31, 2020 and 2019, which had a fair value of $18 million and $24 million at December 31, 2020 and 2019, respectively. The defined benefit pension plan did not purchase any of our common stock during 2020 or 2019. The defined benefit pension plan sold 29,776 shares of our common stock during 2020 and did not sell any shares during 2019. The company paid less than $1 million in 2020 and 2019 in cash dividends on our common stock to the pension plan. We estimate $8 million of benefit payments from the SERP during 2021. We expect to make the following benefit payments for our qualified plan and SERP, reflecting expected future service: (Dollars in millions) Years ended December 31, 2021 2022 2023 2024 2025 2026 - 2030 Expected future benefit payments $ 49 $ 22 $ 25 $ 27 $ 29 $ 163

Statutory Accounting Informatio

Statutory Accounting Information	12 Months Ended
	Dec. 31, 2020
Staturory Accounting Information [Abstract]
Statutory Accounting Information	Statutory Accounting Information Insurance companies’ statutory financial statements are presented on the basis of accounting practices prescribed or permitted by applicable state insurance departments of domicile. Insurance companies use statutory accounting practices (SAP) as recognized by various states. We have adopted the National Association of Insurance Commissioners’ (NAIC) Accounting Practices and Procedures manual, version effective January 1, 2001, and updates through the current year as a component of prescribed or permitted practices by laws of the state of domicile. The primary differences between SAP and GAAP include the valuation of investment gains and losses, expensing of policy acquisition costs, actuarial assumptions for life insurance reserves and deferred income taxes based on differences in statutory and taxable income. Statutory net income and capital and surplus are determined in accordance with SAP prescribed or permitted by insurance regulatory authorities for five legal entities, our lead insurance subsidiary and its four insurance subsidiaries. Statutory capital and surplus for our insurance subsidiary, The Cincinnati Insurance Company, includes capital and surplus of its four insurance subsidiaries. All capital and surplus amounts exceed statutory risk-based capital requirements. The statutory net income and statutory capital and surplus are presented below: (Dollars in millions) Net income Capital and surplus Years ended December 31, At December 31, 2020 2019 2018 2020 2019 The Cincinnati Insurance Company $ 466 $ 558 $ 626 $ 5,838 $ 5,620 The Cincinnati Casualty Company 14 13 16 456 437 The Cincinnati Indemnity Company 3 3 5 115 111 The Cincinnati Specialty Underwriters Insurance Company 42 62 69 528 526 The Cincinnati Life Insurance Company 27 19 — 241 204

Transactions With Affiliated Pa

Transactions With Affiliated Parties	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Transactions With Affiliated Parties	Transactions With Affiliated PartiesWe paid certain officers and directors, or insurance agencies of which they are shareholders, commissions of $7 million in 2020, $8 million in 2019 and $7 million in 2018, on premium volume of $45 million, $48 million and $45 million for 2020, 2019 and 2018, respectively.

Commitments And Contingent Liab

Commitments And Contingent Liabilities	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments And Contingent Liabilities	Commitments and Contingent Liabilities In the ordinary course of conducting business, the company and its subsidiaries are named as defendants in various legal proceedings. Most of these proceedings are claims litigation involving the company’s insurance subsidiaries in which the company is either defending or providing indemnity for third-party claims brought against insureds or litigating first-party coverage claims. The company accounts for such activity through the establishment of unpaid loss and loss expense reserves. We believe that the ultimate liability, if any, with respect to such ordinary-course claims litigation, after consideration of provisions made for potential losses and costs of defense, is immaterial to our consolidated financial condition, results of operations and cash flows. Beginning in April 2020, like many companies in the property casualty insurance industry, the company’s property casualty subsidiaries, were named as defendants in lawsuits seeking insurance coverage under commercial property insurance policies issued by the company for alleged losses resulting from the shutdown or suspension of their businesses due to the COVID-19 pandemic. Although the allegations vary, the plaintiffs generally seek a declaration of insurance coverage, damages for breach of contract in unspecified amounts for claim denials, interest and attorney fees. Some of the lawsuits also allege that the insurance claims were denied in bad faith or otherwise in violation of state laws and seek extra-contractual or punitive damages. The company denies the allegations in these lawsuits and intends to continue to vigorously defend the lawsuits. The company maintains that it has no coverage obligations with respect to these lawsuits for business income allegedly lost by the plaintiffs due to the COVID-19 pandemic based on the terms of the applicable insurance policies. Although the policy terms vary in general, the claims at issue in these lawsuits were denied because the policyholder identified no direct physical loss or damage to property at the insured premises, and the governmental orders that led to the complete or partial shutdown of the business were not due to the existence of any direct physical loss or damage to property in the immediate vicinity of the insured premises and did not prohibit access to the insured premises, as required by the terms of the insurance policies. Depending on the individual policy, additional policy terms and conditions may also prohibit coverage, such as exclusions for pollutants, ordinance or law, loss of use, and acts or decisions. The company’s standard commercial property insurance policies generally did not contain a specific virus exclusion. In addition to the inherent difficulty in predicting litigation outcomes, the COVID-19 pandemic business income coverage lawsuits present a number of uncertainties and contingencies that are not yet known, including how many policyholders will ultimately file claims, the number of lawsuits that will be filed, the extent to which any class may be certified, and the size and scope of any such classes. The legal theories advanced by plaintiffs vary by case as do the state laws that govern the policy interpretation. These lawsuits are in the early stages of litigation; many complaints continue to be amended; several have been dismissed voluntarily and may be refiled; and others have been dismissed by trial courts. Some early decisions on motion filings have been appealed. Accordingly, little discovery has occurred on pending cases and few substantive legal rulings have been made. In addition, business income calculations depend upon a wide range of factors that are particular to the circumstances of each individual policyholder and, here, virtually none of the plaintiffs have submitted proofs of loss or otherwise quantified or factually supported any allegedly covered loss. Moreover, the company’s experience shows that demands for damages often bear little relation to a reasonable estimate of potential loss. Accordingly, management cannot now reasonably estimate the possible loss or range of loss, if any. Nonetheless, given the number of claims and potential claims, the indeterminate amounts sought, and the inherent unpredictability of litigation, it is possible that adverse outcomes, if any, in the aggregate could have a material adverse effect on the company’s consolidated financial condition, results of operations and cash flows. The company and its subsidiaries also are occasionally involved in other legal and regulatory proceedings, some of which assert claims for substantial amounts. These actions include, among others, putative class actions seeking certification of a national class. Such proceedings have alleged, for example, breach of an alleged duty to search national databases to ascertain unreported deaths of insureds under life insurance policies. The company’s insurance subsidiaries also are occasionally parties to individual actions in which extra-contractual damages, punitive damages or penalties are sought, such as claims alleging bad faith handling of insurance claims or writing unauthorized coverage or claims alleging discrimination by former or current associates.

Share-Based Associate Compensat

Share-Based Associate Compensation Plans	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement, Noncash Expense [Abstract]
Stock-Based Associate Compensation Plans	Share-Based Associate Compensation Plans Four equity compensation plans currently permit us to grant various types of equity awards. We currently grant incentive stock options, nonqualified stock options, service-based restricted stock units and performance-based restricted stock units to associates, including some with market-based performance objectives under our shareholder-approved plans. We also have a Holiday Stock Plan that permits annual awards of one share of common stock to each full-time associate for each full calendar year of service up to a maximum of 10 shares. One of our equity compensation plans permits us to grant stock to our outside directors as a component of their annual compensation. We used treasury shares for share-based compensation award issues or exercises during 2020 and 2019. Share-based compensation cost after tax was $25 million, $24 million and $23 million for the years ended December 31, 2020, 2019 and 2018, respectively. The related income tax benefit recognized was $6 million, $6 million , and $5 million for the years ended December 31, 2020, 2019 and 2018, respectively. Options exercised during the years ended December 31, 2020, 2019 and 2018, had intrinsic value of $15 million, $26 million and $15 million, respectively. Intrinsic value is the market price less the exercise price. Options vested during the years ended December 31, 2020, 2019 and 2018, had total intrinsic value of $7 million, $23 million and $6 million, respectively. As of December 31, 2020, we had $34 million of unrecognized total compensation cost related to nonvested stock options and restricted stock unit awards. That cost will be recognized over a weighted-average period of 1.7 years. Stock Options Stock options are granted to associates at an exercise price equal to the fair value as determined by the average high and low sales price reported on the Nasdaq Global Select Market for the grant date and are exercisable over 10-year periods. The stock options generally vest ratably over a three • Weighted-average expected term is based on historical experience of similar awards with consideration for current exercise trends. • Expected volatility is based on our stock price over a historical period that approximates the expected term. • Dividend yield is determined by dividing the annualized per share dividend by the stock price on the date of grant. • Risk-free rates are the implied yield currently available on zero-coupon U.S. Treasury issues with a remaining term approximating the expected term. The following weighted average assumptions were used in determining fair value for option grants issued: 2020 2019 2018 Weighted-average expected term 7-8 years 7-8 years 7-8 years Expected volatility 16.89-17.13% 14.49-15.39% 15.04-15.10% Dividend yield 2.15% 2.61% 2.98% Risk-free rates 1.40-1.41% 2.62-2.64% 2.77-2.83% Weighted-average fair value of options granted during the period $15.45 $11.73 $9.87 Below is a summary of option information for the year 2020: (Dollars in millions, except exercise price. Shares in thousands) Shares Weighted- Aggregate Weighted-average Outstanding option shares at January 1, 2020 3,437 $ 63.99 Granted 508 111.53 Exercised (274) 41.86 Forfeited or expired (70) 55.60 Outstanding option shares at December 31, 2020 3,601 72.55 $ 66 6.01 years Options exercisable at end of period 2,509 $ 63.11 $ 61 4.97 years Cash received from the exercise of options was $7 million, $11 million and $9 million for the years ended December 31, 2020, 2019 and 2018, respectively. We acquired 50,751 , 103,237 and 69,649 shares totaling $5 million, $9 million and $5 million, respectively, from associates in consideration for option exercises during 2020, 2019 and 2018. The weighted-average remaining contractual life for options expected to vest as of December 31, 2020, was 8.38 years. Under all active shareholder approved plans, a total of 17.3 million shares were authorized to be granted. At December 31, 2020, 7.1 million shares remained available for future issuance under the plans. During 2020, we granted 12,928 shares of common stock to our directors for 2019 board service fees. Restricted Stock Units Service-based restricted stock units granted to associates are valued at fair value of the shares on the date of grant less the present value of the dividends that holders of restricted stock units do not receive on the shares underlying the restricted stock units during the vesting period. Service-based restricted stock units generally cliff vest three years after the date of grant. We also grant restricted stock units which vest on a three We have performance-based awards that vest on the first day of March after a three three three Three For the three-year performance period ended December 31, 2020, our total shareholder return exceeded eight of our nine peers. We expect payout of these shares at the maximum level to occur in March of 2021. During 2020, we issued 56,722 shares of performance-based restricted stock units at the target-level performance hurdle for the three-year performance period ended December 31, 2019, as our total shareholder return exceeded five of nine peers in our 2017 peer group. We issued 20,549 shares of performance-based restricted stock units during 2019 at the threshold-level performance hurdle for the three These performance-based awards are valued using a Monte-Carlo valuation on the date of grant, which uses a risk-neutral framework to model future stock price movements based upon the risk-free rate of return, the volatility of each peer and the pairwise correlations of each peer being modeled. Compensation cost is recognized regardless of whether the market-based performance objective has been satisfied. We make assumptions to develop the Monte-Carlo model as follows: • Correlation coefficients are based upon the stock price data used to calculate the historical volatilities. The correlation coefficients are used to model the way the price of each entity's stock tends to move in relation to each other. • Expected volatility is based on each company's historical volatility using daily stock price observations with the period commensurate with the performance measurement period. • Dividend yield has been modeled assuming dividends are reinvested in additional shares of the issuing entity on the ex-dividend date during the performance period. • Risk-free rates are equal to the yield, as of the measurement date, of the zero-coupon U.S. Treasury bill that is commensurate with the performance measurement period. The following assumptions were used in determining fair value for performance-based grants issued: 2020 2019 2018 Expected term 2.86 years 2.86 years 2.89 years Expected volatility 15.88-25.13% 15.10-25.00% 16.01-26.32% Dividend yield 2.15% 2.61% 2.81% Risk-free rates 1.30% 2.48% 2.22% Below is a summary of service-based and performance-based share information, assuming a target payout for performance-based shares, for the year 2020: (Shares in thousands) Service-based Weighted- Performance-based Weighted- Nonvested at January 1, 2020 783 $ 70.27 165 $ 64.23 Granted 204 104.81 38 111.77 Vested (269) 66.53 (56) 43.26 Forfeited or canceled (22) 78.96 — — Nonvested at December 31, 2020 696 81.56 147 84.64

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Segment Information	Segment Information We operate primarily in two industries, property casualty insurance and life insurance. Our chief operating decision maker regularly reviews our reporting segments to make decisions about allocating resources and assessing performance. Our reporting segments are: • Commercial lines insurance • Personal lines insurance • Excess and surplus lines insurance • Life insurance • Investments We report as Other the noninvestment operations of the parent company and its noninsurer subsidiary, CFC Investment Company. We also report as Other the underwriting results of Cincinnati Re and Cincinnati Global. Revenues come primarily from unaffiliated customers: • All four insurance segments record revenues from insurance premiums earned. • Fee revenues for the commercial, personal and excess and surplus insurance segments primarily represent installment fees. Fee revenues for the life insurance segment represent separate account investment management fees. • Our investments’ revenues consist of pretax net investment income and investment gains and losses. • Other revenues are primarily finance income and earned premiums of Cincinnati Re and Cincinnati Global. Income or loss before income taxes for each segment is reported based on the nature of that business area’s operations: • Income before income taxes for the insurance segments is defined as underwriting profit or loss. ◦ For commercial lines, personal lines and excess and surplus lines insurance segments, we calculate underwriting profit or loss as premiums earned and fee revenue minus loss and loss expenses and underwriting expenses incurred. ◦ For the life insurance segment, we calculate underwriting profit or loss as premiums earned and fee revenue, minus contract holders’ benefits and expenses incurred, plus investment interest credited to contract holders. • Income before income taxes for the investments segment is net investment income plus investment gains and losses for investments of the entire company, minus investment interest credited to contract holders of the life insurance segment. • Loss before income taxes for the Other category is primarily due to interest expense from debt of the parent company, operating expenses of our headquarters and premiums earned minus loss and loss expenses and underwriting expenses of Cincinnati Re and Cincinnati Global. We do not separately report the identifiable assets of property casualty insurance for the commercial, personal and excess and surplus lines segments or for Cincinnati Re because we do not use that measure to analyze performance. We include all investment assets, regardless of ownership, in the investments segment. Segment information is summarized in the following table: (Dollars in millions) Years ended December 31, 2020 2019 2018 Revenues: Commercial lines insurance Commercial casualty $ 1,165 $ 1,102 $ 1,075 Commercial property 1,010 958 920 Commercial auto 755 707 664 Workers' compensation 271 300 324 Other commercial 275 252 235 Commercial lines insurance premiums 3,476 3,319 3,218 Fee revenues 3 5 5 Total commercial lines insurance 3,479 3,324 3,223 Personal lines insurance Personal auto 615 621 614 Homeowner 658 607 563 Other personal 190 176 159 Personal lines insurance premiums 1,463 1,404 1,336 Fee revenues 4 4 5 Total personal lines insurance 1,467 1,408 1,341 Excess and surplus lines insurance 325 278 234 Fee revenues 2 2 1 Total excess and surplus lines insurance 327 280 235 Life insurance premiums 289 270 250 Fee revenues 2 4 4 Total life insurance 291 274 254 Investments Investment income, net of expenses 670 646 619 Investment gains and losses, net 865 1,650 (402) Total investment revenue 1,535 2,296 217 Other Premiums 427 333 132 Other 10 9 5 Total other revenue 437 342 137 Total revenues $ 7,536 $ 7,924 $ 5,407 Income (loss) before income taxes: Insurance underwriting results Commercial lines insurance $ 64 $ 241 $ 151 Personal lines insurance 47 8 (20) Excess and surplus lines insurance 34 53 63 Life insurance 11 1 8 Investments 1,433 2,197 121 Other (90) (28) (72) Total income before income taxes $ 1,499 $ 2,472 $ 251 December 31, December 31, Identifiable assets: 2020 2019 Property casualty insurance $ 3,838 $ 3,437 Life insurance 1,661 1,516 Investments 21,332 19,583 Other 711 872 Total $ 27,542 $ 25,408

Quarterly Supplementary Data

Quarterly Supplementary Data	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Quarterly Supplementary Data	Quarterly Supplementary Data This table includes unaudited quarterly financial information for the years ended December 31, 2020 and 2019: (Dollars in millions, except per share data) Quarter 1st 2nd 3rd 4th Full year 2020 Revenues $ (99) $ 2,714 $ 2,227 $ 2,694 $ 7,536 Income (loss) before income taxes (1,576) 1,145 614 1,316 1,499 Net income (loss) (1,226) 909 484 1,049 1,216 Net income (loss) per common share—basic (7.56) 5.65 3.01 6.52 7.55 Net income (loss) per common share—diluted (7.56) 5.63 2.99 6.47 7.49 2019 Revenues $ 2,159 $ 1,913 $ 1,700 $ 2,152 $ 7,924 Income before income taxes 867 530 294 781 2,472 Net income 695 428 248 626 1,997 Net income per common share—basic 4.27 2.62 1.51 3.84 12.24 Net income per common share—diluted 4.22 2.59 1.49 3.79 12.10

Summary Of Investments Other Th

Summary Of Investments Other Than Investments In Related Parties	12 Months Ended
	Dec. 31, 2020
SEC Schedule, 12-15, Insurance Companies, Summary of Investments, Other than Investments in Related Parties [Abstract]
Summary Of Investments Other Than Investments In Related Parties	Schedule I Cincinnati Financial Corporation and Subsidiaries Summary of Investments - Other Than Investments in Related Parties (Dollars in millions) At December 31, 2020 Type of investment Cost or Fair Balance sheet Fixed maturities: States, municipalities and political subdivisions: The Cincinnati Insurance Company $ 3,346 $ 3,638 $ 3,638 The Cincinnati Casualty Company 219 238 238 The Cincinnati Indemnity Company 48 52 52 The Cincinnati Life Insurance Company 357 387 387 The Cincinnati Specialty Underwriters Insurance Company 580 629 629 CSU Producer Resources Inc. 1 1 1 Cincinnati Financial Corporation 53 52 52 Total 4,604 4,997 4,997 United States government: The Cincinnati Insurance Company 65 70 70 The Cincinnati Casualty Company 1 1 1 The Cincinnati Indemnity Company 1 1 1 Cincinnati Global Underwriting Ltd. 48 48 48 Total 115 120 120 Foreign government: The Cincinnati Insurance Company 10 10 10 Cincinnati Global Underwriting Ltd. 19 19 19 Total 29 29 29 Government-sponsored enterprises: Cincinnati Global Underwriting Ltd. 1 1 1 Cincinnati Financial Corporation 11 11 11 Total 12 12 12 All other corporate bonds: The Cincinnati Insurance Company 2,964 3,211 3,211 The Cincinnati Casualty Company 103 110 110 The Cincinnati Indemnity Company 30 33 33 The Cincinnati Life Insurance Company 3,192 3,540 3,540 The Cincinnati Specialty Underwriters Insurance Company 189 211 211 CSU Producer Resources Inc. 1 1 1 Cincinnati Global Underwriting Ltd. 68 69 69 Cincinnati Financial Corporation 5 5 5 Total 6,552 7,180 7,180 Total fixed maturities $ 11,312 $ 12,338 $ 12,338 Schedule I (continued) Cincinnati Financial Corporation and Subsidiaries Summary of Investments - Other Than Investments in Related Parties (Dollars in millions) At December 31, 2020 Type of investment Cost or Fair Balance sheet Equity securities: Common equities: The Cincinnati Insurance Company $ 1,846 $ 4,423 $ 4,423 The Cincinnati Casualty Company 56 146 146 The Cincinnati Indemnity Company 17 36 36 The Cincinnati Specialty Underwriters Insurance Company 96 217 217 CSU Producer Resources Inc. 19 33 33 Cincinnati Financial Corporation 1,606 3,686 3,686 Total 3,640 8,541 8,541 Nonredeemable preferred equities: The Cincinnati Insurance Company 274 299 299 The Cincinnati Life Insurance Company 12 15 15 Cincinnati Financial Corporation 1 1 1 Total 287 315 315 Total equity securities $ 3,927 $ 8,856 $ 8,856 Other invested assets: Policy loans: The Cincinnati Life Insurance Company $ 33 — $ 33 Deposits at Lloyd's: Cincinnati Global Underwriting Ltd. 53 — 53 Cincinnati Financial Corporation 109 — 109 Private equity: The Cincinnati Insurance Company (1) 94 — 94 The Cincinnati Life Insurance Company (1) 3 — 3 Cincinnati Financial Corporation (1) 31 — 31 Real estate: The Cincinnati Insurance Company (1) 11 — 11 The Cincinnati Life Insurance Company (1) 9 — 9 Cincinnati Financial Corporation (1) 5 — 5 Total other invested assets $ 348 — $ 348 Total investments $ 15,587 — $ 21,542

Condensed Financial Statements

Condensed Financial Statements Of Parent Company	12 Months Ended
	Dec. 31, 2020
Condensed Financial Information Disclosure [Abstract]
Condensed Financial Statements Of Parent Company	Schedule II Cincinnati Financial Corporation (parent company only) Condensed Balance Sheets (Dollars in millions) At December 31, 2020 2019 Assets Investments Fixed maturities, at fair value (amortized cost: 2020—$69; 2019—$49) $ 68 $ 49 Equity securities, at fair value (cost: 2020—$1,607; 2019—$1,427) 3,687 3,069 Other invested assets 145 103 Total investments 3,900 3,221 Cash and cash equivalents 16 197 Equity in net assets of subsidiaries 7,982 7,424 Investment income receivable 8 7 Land, building and equipment, net, for company use (accumulated depreciation: 2020—$138; 2019—$129) 143 141 Income tax receivable 5 2 Other assets 53 61 Due from subsidiaries 110 107 Total assets $ 12,217 $ 11,160 Liabilities Dividends declared but unpaid $ 97 $ 91 Deferred federal income tax 429 345 Long-term debt 788 788 Other liabilities 114 72 Total liabilities 1,428 1,296 Shareholders' Equity Common stock 397 397 Paid-in capital 1,328 1,306 Retained earnings 10,085 9,257 Accumulated other comprehensive income 769 448 Treasury stock, at cost (1,790) (1,544) Total shareholders' equity 10,789 9,864 Total liabilities and shareholders' equity $ 12,217 $ 11,160 This condensed financial information should be read in conjunction with the Consolidated Financial Statements and Notes included in Part II, Item 8. Schedule II (continued) Cincinnati Financial Corporation (parent company only) Condensed Statements of Income and Comprehensive Income (Dollars in millions) Years ended December 31, 2020 2019 2018 Revenues Investment income, net of expenses $ 81 $ 75 $ 65 Investment gains and losses, net 556 728 (108) Other revenue 15 15 15 Total revenues 652 818 (28) Expenses Interest expense 54 52 52 Other expenses 34 37 31 Total expenses 88 89 83 Income (Loss) Before Income Taxes and Earnings of Subsidiaries 564 729 (111) Provision (Benefit) for Income Taxes 111 146 (31) Net Income (Loss) Before Earnings of Subsidiaries 453 583 (80) Increase in equity of subsidiaries 763 1,414 367 Net Income $ 1,216 $ 1,997 $ 287 Other Comprehensive Income (Loss), Net of Taxes Change in unrealized gain (loss) on securities — — (2) Amortization of pension actuarial gains (losses) and prior service costs (25) 5 (3) Other Comprehensive Income (Loss), Net of Taxes Before Other Comprehensive Income (25) 5 (5) Other comprehensive income (loss) of subsidiaries 346 421 (258) Other comprehensive income (loss) 321 426 (263) Comprehensive Income $ 1,537 $ 2,423 $ 24 This condensed financial information should be read in conjunction with the Consolidated Financial Statements and Notes included in Part II, Item 8. Schedule II (continued) Cincinnati Financial Corporation (parent company only) Condensed Statements of Cash Flows (Dollars in millions) Years ended December 31, 2020 2019 2018 Cash Flows From Operating Activities Net income $ 1,216 $ 1,997 $ 287 Adjustments to reconcile net income to net cash provided by operating activities: Depreciation and amortization 12 10 7 Investment gains and losses, net (552) (720) 114 Dividends from subsidiaries 550 625 500 Changes in: Increase in equity of subsidiaries (763) (1,414) (367) Investment income receivable (1) (1) 2 Current federal income taxes (3) (1) 14 Deferred income tax 91 146 (35) Other assets — 4 (17) Other liabilities 1 4 3 Intercompany receivable for operations 34 20 19 Net cash provided by operating activities 585 670 527 Cash Flows From Investing Activities Sale of fixed maturities — 3 1 Call or maturity of fixed maturities 1 21 19 Sale of equity securities 307 122 131 Purchase of fixed maturities (23) (39) (17) Purchase of equity securities (372) (237) (177) Investment in buildings and equipment (11) (13) (12) Cash paid for acquisition — (63) — Change in other invested assets, net (42) (67) (11) Net cash used in investing activities (140) (273) (66) Cash Flows From Financing Activities Payment of cash dividends to shareholders (375) (355) (336) Shares acquired - share repurchase authorization (261) (67) (125) Proceeds from stock options exercised 7 11 9 Other 3 2 1 Net cash used in financing activities (626) (409) (451) Net change in cash and cash equivalents (181) (12) 10 Cash and cash equivalents at beginning of year 197 209 199 Cash and cash equivalents at end of year $ 16 $ 197 $ 209

Supplementary Insurance Informa

Supplementary Insurance Information	12 Months Ended
	Dec. 31, 2020
SEC Schedule, 12-16, Insurance Companies, Supplementary Insurance Information [Abstract]
Supplementary Insurance Information	Schedule III Cincinnati Financial Corporation and Subsidiaries Supplementary Insurance Information (Dollars in millions) Years ended December 31, 2020 2019 2018 Deferred policy acquisition costs: Commercial lines insurance $ 317 $ 311 $ 291 Personal lines insurance 136 130 126 Excess and surplus lines insurance 28 25 21 Other 61 46 26 Total property casualty insurance 542 512 464 Life insurance 263 262 274 Total $ 805 $ 774 $ 738 Gross future policy benefits, losses, claims and expense losses: Commercial lines insurance $ 4,881 $ 4,569 $ 4,466 Personal lines insurance 739 687 679 Excess and surplus lines insurance 446 351 298 Other 611 481 203 Total property casualty insurance 6,677 6,088 5,646 Life insurance 2,938 2,859 2,802 Total (1) $ 9,615 $ 8,947 $ 8,448 Gross unearned premiums: Commercial lines insurance $ 1,714 $ 1,665 $ 1,576 Personal lines insurance 797 757 725 Excess and surplus lines insurance 175 152 123 Other 273 213 91 Total property casualty insurance 2,959 2,787 2,515 Life insurance 1 1 1 Total (1) $ 2,960 $ 2,788 $ 2,516 Other policy claims and benefits payable: Commercial lines insurance $ — $ — $ — Personal lines insurance — — — Excess and surplus lines insurance — — — Other — — — Total property casualty insurance — — — Life insurance 46 35 38 Total (1) $ 46 $ 35 $ 38 Earned premiums: Commercial lines insurance $ 3,476 $ 3,319 $ 3,218 Personal lines insurance 1,463 1,404 1,336 Excess and surplus lines insurance 325 278 234 Other 427 333 132 Total property casualty insurance 5,691 5,334 4,920 Life insurance 289 270 250 Total $ 5,980 $ 5,604 $ 5,170 Schedule III (continued) Cincinnati Financial Corporation and Subsidiaries Supplementary Insurance Information (Dollars in millions) Years ended December 31, 2020 2019 2018 Investment income, net of expenses: Commercial lines insurance $ — $ — $ — Personal lines insurance — — — Excess and surplus lines insurance — — — Other — — — Total property casualty insurance (2) 431 419 401 Life insurance 158 152 153 Total $ 589 $ 571 $ 554 Benefits, claims losses and settlement expenses: Commercial lines insurance $ 2,336 $ 2,030 $ 2,049 Personal lines insurance 977 985 972 Excess and surplus lines insurance 199 142 104 Other 325 195 98 Total property casualty insurance 3,837 3,352 3,223 Life insurance 297 286 267 Total $ 4,134 $ 3,638 $ 3,490 Amortization of deferred policy acquisition costs: Commercial lines insurance $ 664 $ 631 $ 608 Personal lines insurance 256 251 242 Excess and surplus lines insurance 51 47 39 Other 86 57 18 Total property casualty insurance 1,057 986 907 Life insurance 49 48 39 Total (3) $ 1,106 $ 1,034 $ 946 Underwriting, acquisition and insurance expenses: Commercial lines insurance $ 415 $ 422 $ 415 Personal lines insurance 187 164 147 Excess and surplus lines insurance 43 38 29 Other 42 42 24 Total property casualty insurance 687 666 615 Life insurance 36 38 36 Total (3) $ 723 $ 704 $ 651 Net written premiums: Commercial lines insurance $ 3,534 $ 3,410 $ 3,245 Personal lines insurance 1,503 1,435 1,378 Excess and surplus lines insurance 348 303 249 Other 479 368 158 Total property casualty insurance 5,864 5,516 5,030 Accident and health insurance 2 2 3 Total $ 5,866 $ 5,518 $ 5,033 Notes to Schedule III: (1) The sum of gross future policy benefits, losses, claims and expense losses, gross unearned premiums and other policy claims and benefits payable is equal to the sum of Loss and loss expense reserves, Life policy reserves and investment contract reserves and Unearned premiums reported in the company’s consolidated balance sheets. (2) This segment information is not regularly allocated to segments and reviewed by company management in making decisions about resources to be allocated to the segments or to assess their performance. (3) The sum of amortization of deferred policy acquisition costs and other underwriting and insurance expenses is equal to Underwriting, acquisition and insurance expenses in the consolidated statements of income.

Reinsurance - Schedule IV

Reinsurance - Schedule IV	12 Months Ended
	Dec. 31, 2020
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Abstract]
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Text Block]	Schedule IV Cincinnati Financial Corporation and Subsidiaries Reinsurance (Dollars in millions) Years ended December 31, 2020 2019 2018 Gross amounts: Life insurance in force $ 111,756 $ 108,130 $ 104,726 Earned premiums Commercial lines insurance $ 3,578 $ 3,421 $ 3,314 Personal lines insurance 1,503 1,446 1,372 Excess and surplus lines insurance 341 292 245 Other 201 181 — Total property casualty insurance 5,623 5,340 4,931 Life insurance 362 341 320 Total $ 5,985 $ 5,681 $ 5,251 Ceded amounts to other companies: Life insurance in force $ 38,281 $ 38,146 $ 38,584 Earned premiums Commercial lines insurance $ 109 $ 109 $ 104 Personal lines insurance 41 43 37 Excess and surplus lines insurance 16 14 11 Other 51 39 8 Total property casualty insurance 217 205 160 Life insurance 73 71 70 Total $ 290 $ 276 $ 230 Assumed amounts from other companies: Life insurance in force $ — $ — $ — Earned premiums Commercial lines insurance $ 7 $ 7 $ 8 Personal lines insurance 1 1 1 Excess and surplus lines insurance — — — Other 277 191 140 Total property casualty insurance 285 199 149 Life insurance — — — Total $ 285 $ 199 $ 149 Net amounts: Life insurance in force $ 73,475 $ 69,984 $ 66,142 Earned premiums Commercial lines insurance $ 3,476 $ 3,319 $ 3,218 Personal lines insurance 1,463 1,404 1,336 Excess and surplus lines insurance 325 278 234 Other 427 333 132 Total property casualty insurance 5,691 5,334 4,920 Life insurance 289 270 250 Total $ 5,980 $ 5,604 $ 5,170 Percentage of amounts assumed to net: Life insurance in force — % — % — % Earned premiums Commercial lines insurance 0.2 % 0.2 % 0.3 % Personal lines insurance 0.1 0.1 0.1 Excess and surplus lines insurance — — — Other 64.9 57.4 106.1 Total property casualty insurance 5.0 3.7 3.0 Life insurance — — — Total 4.8 3.6 2.9

Valuation And Qualifying Accoun

Valuation And Qualifying Accounts	12 Months Ended
	Dec. 31, 2020
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Valuation And Qualifying Accounts	Schedule V Cincinnati Financial Corporation and Subsidiaries Valuation and Qualifying Accounts (Dollars in millions) At December 31, 2020 2019 2018 Allowance for credit losses (1): Beginning balance, January 1 $ 8 $ 6 $ 6 Cumulative effect of change in accounting for credit losses as of January 1, 2020, pretax 3 — — Additions charged to costs and expenses 19 8 6 Deductions (8) (6) (6) Ending balance, December 31 $ 22 $ 8 $ 6 Deferred tax valuation allowance: Beginning balance, January 1 $ 41 $ — $ — Additions charged to costs and expenses 15 55 — Deductions — (14) — Ending balance, December 31 56 41 — Total valuation and qualifying accounts $ 78 $ 49 $ 6 Notes to Schedule V:

Supplementary Information Conce

Supplementary Information Concerning Property Casualty Insurance Operations	12 Months Ended
	Dec. 31, 2020
SEC Schedule, 12-18, Supplemental Information, Property-Casualty Insurance Underwriters [Abstract]
Supplementary Information Concerning Property Casualty Insurance Operations	Schedule VI Cincinnati Financial Corporation and Subsidiaries Supplementary Information Concerning Property Casualty Insurance Operations (Dollars in millions) Years ended December 31, 2020 2019 2018 Deferred policy acquisition costs: Commercial lines insurance $ 317 $ 311 $ 291 Personal lines insurance 136 130 126 Excess and surplus lines insurance 28 25 21 Other 61 46 26 Total $ 542 $ 512 $ 464 Reserves for unpaid claims and claim adjustment expenses: Commercial lines insurance $ 4,881 $ 4,569 $ 4,466 Personal lines insurance 739 687 679 Excess and surplus lines insurance 446 351 298 Other 611 481 203 Total $ 6,677 $ 6,088 $ 5,646 Reserve discount deducted $ — $ — $ — Gross unearned premiums: Commercial lines insurance $ 1,714 $ 1,665 $ 1,576 Personal lines insurance 797 757 725 Excess and surplus lines insurance 175 152 123 Other 273 213 91 Total $ 2,959 $ 2,787 $ 2,515 Earned premiums: Commercial lines insurance $ 3,476 $ 3,319 $ 3,218 Personal lines insurance 1,463 1,404 1,336 Excess and surplus lines insurance 325 278 234 Other 427 333 132 Total $ 5,691 $ 5,334 $ 4,920 Investment income, net of expenses: Commercial lines insurance $ — $ — $ — Personal lines insurance — — — Excess and surplus lines insurance — — — Other — — — Total (1) $ 431 $ 419 $ 401 Note to Schedule VI: (1) This segment information is not regularly allocated to segments and not reviewed by company management in making decisions about resources to be allocated to the segments or to assess their performance. Schedule VI (continued) Cincinnati Financial Corporation and Subsidiaries Supplementary Information Concerning Property Casualty Insurance Operations (Dollars in millions) Years ended December 31, 2020 2019 2018 Loss and loss expenses incurred related to current accident year: Commercial lines insurance $ 2,431 $ 2,222 $ 2,206 Personal lines insurance 995 1,012 960 Excess and surplus lines insurance 192 153 128 Other 350 213 96 Total $ 3,968 $ 3,600 $ 3,390 Loss and loss expenses incurred related to prior accident years: Commercial lines insurance $ (95) $ (192) $ (157) Personal lines insurance (18) (27) 13 Excess and surplus lines insurance 7 (11) (24) Other (25) (18) 1 Total $ (131) $ (248) $ (167) Amortization of deferred policy acquisition costs: Commercial lines insurance $ 664 $ 631 $ 608 Personal lines insurance 256 251 242 Excess and surplus lines insurance 51 47 39 Other 86 57 18 Total $ 1,057 $ 986 $ 907 Paid loss and loss expenses: Commercial lines insurance $ 1,969 $ 2,023 $ 1,816 Personal lines insurance 921 966 913 Excess and surplus lines insurance 112 90 74 Other 181 181 44 Total $ 3,183 $ 3,260 $ 2,847 Net written premiums: Commercial lines insurance $ 3,534 $ 3,410 $ 3,245 Personal lines insurance 1,503 1,435 1,378 Excess and surplus lines insurance 348 303 249 Other 479 368 158 Total $ 5,864 $ 5,516 $ 5,030

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Nature of Operations	Nature of Operations Cincinnati Financial Corporation (CFC) operates through The Cincinnati Insurance Company and Cincinnati Global Underwriting Ltd. SM (Cincinnati Global) insurance subsidiaries and two complementary subsidiary companies. Cincinnati Global, our London-based global specialty underwriter, was acquired effective February 28, 2019. The Cincinnati Insurance Company leads our insurance group that also includes two subsidiaries: The Cincinnati Casualty Company and The Cincinnati Indemnity Company. This group markets a broad range of standard market commercial and personal policies. The group focuses on delivery of quality customer service to our select group of 1,848 independent insurance agencies with 2,578 reporting locations acros s 45 states . Other subsidiaries of The Cincinnati Insurance Company include: The Cincinnati Life Insurance Company, which markets life insurance and fixed annuities; and The Cincinnati Specialty Underwriters Insurance Company, which offers excess and surplus lines property casualty insurance products. The Cincinnati Insurance Company also conducts the business of our reinsurance assumed operations, Cincinnati Re ® . The two CFC complementary subsidiaries are CSU Producer Resources Inc., which provides insurance brokerage services to our independent agencies so their clients can access our excess and surplus lines insurance products, and CFC Investment Company, which offers commercial leasing and financing services to our agents, their clients and other customers. The World Health Organization declared the 2019 novel coronavirus (SARS-CoV-2 or COVID-19) outbreak a Public Health Emergency of International Concern on January 30, 2020, and a pandemic on March 11, 2020. The pandemic outbreak has caused an economic downturn on a global scale and although many businesses have resumed operations at some capacity, there is still uncertainty surrounding future government and private company restrictions. The pandemic, and unprecedented actions taken to contain the virus, has also continued to cause market disruption and volatility.
Basis of Presentation	Basis of Presentation Our consolidated financial statements include the accounts of the parent and its wholly owned subsidiaries and are presented in conformity with accounting principles generally accepted in the United States of America (GAAP). The 2019 consolidated financial statements include Cincinnati Global's results for the period from February 28, 2019, through December 31, 2019. Foreign exchange rates related to Cincinnati Global's operations did not have a material impact to our consolidated financial statements. All intercompany balances and transactions have been eliminated in consolidation. The preparation of the consolidated financial statements in conformity with GAAP requires us to make estimates and assumptions that affect amounts reported in the consolidated financial statements and accompanying notes. Our actual results could differ from those estimates.
Investments	Investments Our portfolio investments are primarily in publicly traded fixed-maturity and equity security investments. Fixed-maturity investments (taxable bonds, tax-exempt bonds, redeemable preferred equities and commercial mortgage- backed securities) classified as available for sale and equity investments (common and nonredeemable preferred equities) are recorded at fair value in the consolidated financial statements. Changes in fair value of fixed-maturity securities are reported in other comprehensive income while equity securities are reported in net income. The number of fixed-maturity securities with fair values below 100% of amortized cost can be expected to fluctuate as interest rates rise or fall. Because of our strong capital and long-term investment horizon, our general intent is to hold fixed-maturity investments until maturity, regardless of short-term fluctuations in fair values. An available for sale fixed maturity is impaired if the fair value of the security is below amortized cost. The impaired loss is charged to net income when we have the intent to sell the security or it is more likely than not we will be required to sell the security before recovery of the amortized cost. For impaired securities we intend to hold, an allowance for credit related losses is recorded in investment losses when the company determines a credit loss has been incurred based on certain factors such as adverse conditions, credit rating downgrades or failure of the issuer to make scheduled principal or interest payments. A credit loss is determined using a discounted cash flow analysis by comparing the present value of expected cash flows with the amortized cost basis, limited to the difference between fair value and amortized cost. Noncredit losses are recognized in other comprehensive income as a change in unrealized gains and losses on investments. As securities are sold, we recognize the gain or loss in income based on the trade date. Included within our other invested assets were $162 million and $164 million held on deposit at Lloyd's, $128 million and $71 million of private equity investments, $33 million and $32 million of life policy loans and $25 million and $29 million of real estate through direct property ownership and development projects in the United States at December 31, 2020 and 2019, respectively. Lloyd's deposits primarily consist of highly liquid short-term investment instruments. The private equity investments provide their financial statements to us and generally report investments on their balance sheets at fair value. We use the equity method of accounting for private equity and real estate development investments. Life policy loans are carried at the receivable value. Investment income, net of expenses, consists mainly of interest and dividends. We record interest on an accrual basis and record dividends at the ex-dividend date. We amortize premiums and discounts on fixed-maturity securities using the effective interest method over the expected life of the security.
Fair Value Disclosures	Fair Value Disclosures Fair value is defined as the exit price or the amount that would be (1) received to sell an asset or (2) paid to transfer a liability in an orderly transaction between marketplace participants at the measurement date. When determining an exit price, we rely upon observable market data whenever possible. We primarily base fair value for investments in equity and fixed-maturity securities (including redeemable preferred stock and assets held in separate accounts) on quoted market prices or on prices from the company’s nationally recognized pricing vendors, outside resources that supply global securities pricing, dividend, corporate action and descriptive information to support fund pricing, securities operations, research and portfolio management. The company obtains and reviews the pricing services' valuation methodologies and related inputs and validates these prices by replicating a sample across each asset class using a discounted cash flow model. When a price is not available from these sources, as in the case of securities that are not publicly traded, we determine the fair value using various inputs including quotes from independent brokers. The fair value of investments not priced by the company’s nationally recognized pricing vendors is immaterial. For the purpose of Accounting Standards Codification (ASC) 825, Financial Instruments disclosure, we estimate the fair value of our long-term senior notes on market pricing of similar debt instruments that are actively trading. We estimate the fair value of our note payable on the year-end outstanding balance because it is short term and tied to a variable interest rate. We estimate the fair value of liabilities for investment contracts and annuities using discounted cash flow calculations across a wide range of economic interest rate scenarios with a provision for our nonperformance risk. We estimate the fair value for policyholder loans on insurance contracts using a discounted cash flow model. Determination of fair value for structured settlements assumes the discount rates used to calculate the present value of expected payments are the risk-free spot rates plus an A3 rated bond spread for financial issuers at December 31, 2020, to account for nonperformance risk. See Note 3, Fair Value Measurements, for further details.
Cash And Cash Equivalents	Cash and Cash EquivalentsCash and cash equivalents are highly liquid instruments that include liquid debt instruments with original maturities of less than three months. These are carried at cost, which approximates fair value.
Property Casualty Insurance	Property Casualty Insurance The consolidated property casualty companies actively write property casualty insurance through independent agencies i n 45 states. Our 10 largest states generated 53.3% and 54.8% of total earned premiums in 2020 and 2019, respectively. Ohio, our largest state, accounted for 14.8% and 15.1% of total earned premiums in 2020 and 2019, respectively. Illinois, Georgia, North Carolina, Pennsylvania and Indiana each accounted for between 4% and 6% of total earned premiums in 2020. Our largest single agency relationship accounted for approximately 1.3% of our total property casualty earned premiums in 2020. No aggregate agency relationship locations under a single ownership structure accounted for more than 4% of our total property casualty earned premiums in 2020. We record revenues for installment charges as fee revenues in the consolidated statements of income. Property casualty written premiums are deferred and recorded as earned premiums primarily on a pro rata basis over the terms of the policies. We record as unearned premiums the portion of written premiums that applies to unexpired policy terms. Expenses associated with successfully acquiring insurance policies – commissions, premium taxes and underwriting costs – are deferred and amortized over the terms of the policies. We assess recoverability of deferred acquisition costs at a level consistent with the way we acquire, service and manage insurance policies and measure profitability. We analyze our acquisition cost assumptions to reflect actual experience, and we evaluate potential premium deficiencies. Certain property casualty policies are not entered into policy underwriting systems as of the effective date of coverage. An estimate is recorded for these unprocessed written premiums. A large majority of the estimate is unearned and has no material impact on earned premiums. An allowance for credit losses on uncollectible property casualty premiums is updated and reviewed on a quarterly basis. At January 1, 2020, the allowance was $9 million. At December 31, 2020, the allowance increased to $19 million, of which a significant portion was due to consideration of pandemic-related factors. Other changes in the amount during 2020 were immaterial.
Policyholder Dividends	Policyholder Dividends Certain workers’ compensation policies include the possibility of a policyholder earning a return of a portion of premium in the form of a policyholder dividend. The dividend generally is calculated by determining the profitability of a policy year along with the associated premium. We reserve for all probable future policyholder dividend payments. We record policyholder dividends as other underwriting expenses.
Life Insurance	Life Insurance We offer several types of life insurance and we account for each according to the duration of the contract. Short-duration life and health contracts are written to cover claims that arise during a short, fixed term of coverage. We generally have the right to change the amount of premium charged or cancel the coverage at the end of each contract term. We record premiums for short-duration life and health contracts similarly to property casualty contracts. Long-duration contracts are written to provide coverage for an extended period of time. Traditional long-duration contracts require policyholders to pay scheduled gross premiums, generally not less frequently than annually, over the term of the coverage. Premiums for these contracts, such as whole life insurance are recognized as revenue when due. Some traditional long-duration contracts, such as ten-pay whole life insurance, have premium payment periods shorter than the period over which coverage is provided. For these contracts, the excess of premium over the amount required to pay expenses and benefits is recognized over the term of the coverage rather than over the premium payment period. We establish a liability for traditional long-duration contracts as we receive premiums. The amount of this liability is the present value of future expenses and benefits less the present value of future net premiums. Net premium is the portion of gross premium required to provide for all expenses and benefits. We estimate future expenses and benefits and net premium using assumptions for expected expenses, mortality, morbidity, withdrawal rates and investment income. We include a provision for deviation, meaning we allow for some uncertainty in making our assumptions. We establish our assumptions when the contract is issued, and we generally maintain those assumptions for the life of the contract. We use both our own experience and industry experience, adjusted for historical trends, in arriving at our assumptions for expected mortality, morbidity and withdrawal rates. We use our own experience and historical trends for setting our assumption for expected expenses. We base our assumption for expected investment income on our own experience, adjusted for current and future economic conditions. We capitalize acquisition costs for traditional long-duration contracts. We charge these capitalized costs associated with successfully acquiring traditional long-duration contract insurance policies in proportion to premium revenue recognized. We use the same assumptions used in establishing the liability for the contract. We update our acquisition cost assumptions periodically to reflect actual experience, and we evaluate our deferred acquisition costs for recoverability. Universal life contracts are long-duration contracts for which contractual provisions are not fixed, unlike whole life insurance. Universal life contracts allow policyholders to vary the amount of premium, within limits, without our consent. However, we may vary the mortality, expense charges and the interest crediting rate, within limits, used to accumulate policy values. We do not record universal life premiums as revenue. Instead we recognize as revenue the mortality charges, administration charges and surrender charges when received. Some of our universal life contracts assess administration charges in the early years of the contract that are compensation for services we will provide in the later years of the contract. These administration charges are deferred and are recognized over the period when we provide those future services. We maintain a policy reserve liability equal to the policyholder account value. There is no provision for adverse deviation. Some of our universal life policies contain no-lapse guarantee provisions. For these policies, we establish a reserve in addition to the account balance, based on expected no-lapse guarantee benefits and expected policy assessments. We capitalize acquisition costs associated with successfully acquiring universal life long-duration contracts. We charge these capitalized costs to expenses over the term of coverage of the contract in accordance with the recognition of gross profit from the contract or notional benefit base. When we charge deferred policy acquisition costs to expenses, we use assumptions based on our best estimates of long-term experience. We review and modify these assumptions on a regular basis.
Separate Accounts	Separate Accounts We have issued universal life contracts with guaranteed minimum returns, referred to as bank-owned life insurance contracts (BOLIs). A BOLI is designed so the bank is the policy owner and the policy beneficiary. We legally segregate and record as separate accounts the assets and liabilities for some of our BOLIs, based on the specific contract provisions. We guarantee minimum investment returns, account values and death benefits for our separate account BOLIs. Our other BOLIs are general account products. We carry the assets of separate account BOLIs at fair value. The liabilities on separate account BOLIs primarily are the contract holders’ claims to the related assets and are carried at an amount equal to the contract holders’ account value. At December 31, 2020 and 2019, the current fair value of th e BOLI invested assets and cash exceeded the current fair value of the contract holders’ account value by approximately $99 million and $52 million, respectively. If the BOLI projected fair value were to fall below the value we guaranteed, a liability would be established with a corresponding charge to the company’s earnings.
Reinsurance	Reinsurance The Cincinnati Insurance Company offers reinsurance assumed for casualty (predominantly domestic exposure), specialty and property (worldwide exposure). Treaties are written on a pro rata and excess of loss basis. We also continue to assume risk with limited exposure as a reinsurer for involuntary state pools. Written premium is recorded, net of contract specific retrocessions, on an ultimate estimate basis and primarily earned on a pro rata basis over the coverage period of the treaty. Expenses are recorded as per contract terms and deferred over the earning period of the premium. We establish known loss reserves when reported. We establish reserves for losses in excess of reported activity in the form of IBNR. Reserves are established using actuarial analysis, which includes models and methods traditionally used for the types of exposures written. We establish reserves for event specific occurrences using modeling data and company specific data when available. We enter into other reinsurance transactions to reduce risk and uncertainty by buying property casualty reinsurance and retrocessional reinsurance as well as life reinsurance. Reinsurance and retrocessional reinsurance contracts do not relieve us from our obligation to policyholders, but rather help protect our financial strength to perform that duty. All of these ceded reinsurance contracts transfer the economic risk of loss. Premiums that we cede are deferred and recorded as earned premiums on a pro rata basis over the terms of the contracts. We estimate loss amounts recoverable from our reinsurers based on the reinsurance policy terms. Historically, our claims with reinsurers have been paid. An allowance for credit losses on uncollectible reinsurance premiums and recoverable assets is updated and reviewed on a quarterly basis. The allowances, including changes in the amounts during 2020, were immaterial to our consolidated financial condition, results of operations and cash flows.
Income Taxes	Income Taxes We calculate deferred income tax liabilities and assets using tax rates in effect when temporary differences in the consolidated financial statement income and taxable income are expected to reverse. We recognize deferred income taxes for numerous temporary differences between our taxable income and consolidated financial statement income and other changes in shareholders’ equity. Such temporary differences relate primarily to unrealized gains and losses on investments and differences in the recognition of deferred acquisition costs, unearned premiums, insurance reserves and basis differences in the carrying value of investments held. We charge deferred income taxes associated with balances that impact other comprehensive income, such as unrealized gains and losses of fixed-maturity investments, to shareholders’ equity in accumulated other comprehensive income (AOCI). We charge deferred taxes associated with other differences to income. See Note 11, Income Taxes, for further detail on our uncertain tax positions and other income tax items. Although no Internal Revenue Service (IRS) penalties currently are accrued, if incurred, they would be recognized as a component of income tax expense.
Earnings per Share	Earnings per Share Net income per common share is based on the weighted average number of common shares outstanding during each of the respective years. We calculate net income per common share (diluted) assuming the exercise or conversion of share‑based awards using the treasury stock method.
Land, Building And Equipment	Land, Building and Equipment We record land at cost, and record building and equipment at cost less accumulated depreciation. Equipment held under finance leases also is classified as property and equipment with the related lease obligations recorded as liabilities. We capitalize and amortize costs for internally developed computer software during the application development stage. These costs generally consist of external consulting, internal payroll and payroll-related costs. Our depreciation is based on estimated useful lives (ranging from three We monitor land, building and equipment and software assets for potential impairments. Indicators of potential impairments may include a significant decrease in the fair values of the assets, considerable cost overruns on projects, a change in legal factors or business climate or other factors that indicate that the carrying amount may not be recoverable or useful. There were no recorded land, building and equipment impairments for 2020, 2019 or 2018.
Finance Receivables	Finance ReceivablesOur leasing subsidiary provides auto and equipment direct financing (leases and loans) to commercial and individual clients. We generally transfer ownership of the property to the client as the terms of the leases expire. Our lease contracts contain bargain purchase options. We account for these leases and loans as sales-type leases. We capitalize and amortize lease or loan origination costs over the life of the financing, using the effective interest method. These costs may include, but are not limited to finder fees, broker fees, filing fees and the cost of credit reports. We record income as other revenues over the financing term using the effective interest method in the consolidated statements of income. An allowance for credit losses on finance receivables is updated and reviewed on a quarterly basis. The allowance, including changes in the amount during 2020, was immaterial to our consolidated financial condition, results of operations and cash flows.
Employee Benefit Pension Plan	Employee Benefit Pension Plan We sponsor a qualified defined benefit pension plan that was modified during 2008. We closed entry into the pension plan, and only participants 40 years of age or older could elect to remain in the plan. Our pension expenses are based on certain actuarial assumptions and also are composed of several components that are determined using the projected unit credit actuarial cost method. Refer to Note 13, Employee Retirement Benefits, for more information about our defined benefit pension plan.
Stock-Based Compensation	Share-Based Compensation We grant qualified and nonqualified share-based compensation under authorized plans. The stock options generally vest on a graded scale over three years following the date of grant and are exercisable over 10-year periods. We grant service-based restricted stock units that cliff vest three years after the date of grant as well as service-based restricted stock units that vest ratably over the three
Goodwill and Intangible Assets, Policy	Goodwill and Intangible Assets We recognize goodwill and intangible assets generated through acquisitions within other assets in the consolidated balance sheets. Goodwill arises when the fair value of consideration transferred exceeds the fair value of the net identifiable assets acquired at the acquisition date. Goodwill and intangible assets with an indefinite life are not amortized. Intangible assets with a definite life are amortized on a straight-line basis over the estimated useful lives as follows: broker relationships, 15 years; internally developed technology, five years; value of business acquired, over the remaining coverage period of the underlying insurance contracts, which expired during 2020. We test for impairments on an annual basis or more frequently if events or circumstances indicate that the asset might be impaired. The company performed its annual impairment test on goodwill and intangibles on September 30, which did not result in the recognition of an impairment loss. The company held goodwill of $30 million and intangible assets with an indefinite life of $31 million at December 31, 2020 and 2019, respectively.
Subsequent Events	Subsequent EventsThere were no subsequent events requiring adjustment to the consolidated financial statements or disclosure.
Accounting Updates	Adopted Accounting Updates ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments In June 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments, as well as additional implementation related ASU's in 2018, 2019 and 2020. These ASU’s amend previous guidance on the impairment of financial instruments by adding an impairment model that allows an entity to recognize expected credit losses as an allowance rather than impairing as they are incurred. The new guidance is intended to reduce the complexity of credit impairment models and result in a more timely recognition of expected credit losses. The standards require the company to consider all relevant information at the time of estimating the expected credit loss, including past events, the current environment, and reasonable and supportable forecasts over the life of the asset. These ASU's also eliminated the other-than-temporary impairment model for available for sale fixed-maturity securities by requiring that credit-related impairments be recognized through an allowance account. Changes in the allowance account are recorded in the period of change as a credit loss expense or reversal of credit loss expense. The measurement of credit losses is not impacted, except that credit losses recognized are limited to the amount by which fair value is below amortized cost and that the length of time that a security has been below amortized cost cannot be considered. These ASU's retain the guidance requiring that impaired securities intended to be sold have their amortized cost basis written down to fair value through net income. The company adopted these ASU's on January 1, 2020, and applied them on a modified retrospective basis. As a result of this adoption, an after-tax cumulative effect decrease of $2 million was made to retained earnings representing an increase to the overall valuation allowances for financial instruments measured at amortized cost. These ASU's were applied to available for sale fixed-maturity securities prospectively with no adjustments to the amortized cost basis of securities for which an other-than-temporary impairment had been previously recognized. The company has elected not to measure expected credit losses for accrued interest receivables related to its finance receivables and fixed-maturity securities. Pending Accounting Updates ASU 2018-12, Financial Services - Insurance (Topic 944): Targeted Improvements to the Accounting for Long-Duration Contracts In August 2018, the FASB issued ASU 2018-12, Financial Services - Insurance (Topic 944): Targeted Improvements to the Accounting for Long-Duration Contracts . ASU 2018-12 is intended to improve the timeliness of recognizing changes in the liability for future policy benefits and modify the rate used to discount future cash flows. The ASU will simplify and improve the accounting for certain market-based options or guarantees associated with deposit or account balance contracts and simplify amortization of deferred acquisition costs while improving and expanding required disclosures. In November 2020, the FASB issued an ASU that delayed the effective date of ASU 2018-12 to interim and annual reporting periods beginning after December 15, 2022. These ASU's have not yet been adopted. Management is currently evaluating the impact on our company's consolidated financial condition, results of operations and cash flows.

Investments (Tables)

Investments (Tables)	12 Months Ended
	Dec. 31, 2020
Investments [Abstract]
Analysis Of Cost Or Amortized Cost, Gross Unrealized Gains And Losses And Fair Value for Investments	The following table provides amortized cost, gross unrealized gains, gross unrealized losses and fair value for our fixed-maturity securities: (Dollars in millions) Amortized Gross unrealized Fair At December 31, 2020 gains losses Fixed-maturity securities: Corporate $ 6,281 $ 621 $ 7 $ 6,895 States, municipalities and political subdivisions 4,604 395 2 4,997 Commercial mortgage-backed 271 15 1 285 United States government 115 5 — 120 Foreign government 29 — — 29 Government-sponsored enterprises 12 — — 12 Total $ 11,312 $ 1,036 $ 10 $ 12,338 At December 31, 2019 Fixed-maturity securities: Corporate $ 6,074 $ 332 $ 5 $ 6,401 States, municipalities and political subdivisions 4,477 252 1 4,728 Commercial mortgage-backed 290 11 — 301 United States government 102 2 — 104 Foreign government 28 — — 28 Government-sponsored enterprises 137 — 1 136 Total $ 11,108 $ 597 $ 7 $ 11,698
Fair Values And Unrealized Losses by Investment Category And By The Duration Of The Securities' Continuous Unrealized Loss Position	The table below provides fair values and unrealized losses by investment category and by the duration of the securities’ continuous unrealized loss positions: (Dollars in millions) Less than 12 months 12 months or more Total At December 31, 2020 Fair Unrealized Fair Unrealized Fair Unrealized Fixed-maturity securities: Corporate $ 330 $ 5 $ 46 $ 2 $ 376 $ 7 States, municipalities and political subdivisions 31 2 2 — 33 2 Commercial mortgage-backed 23 1 6 — 29 1 United States government 12 — — — 12 — Foreign government 10 — — — 10 — Total $ 406 $ 8 $ 54 $ 2 $ 460 $ 10 At December 31, 2019 Fixed-maturity securities: Corporate $ 199 $ 2 $ 118 $ 3 $ 317 $ 5 States, municipalities and political subdivisions 98 1 10 — 108 1 Commercial mortgage-backed 6 — — — 6 — United States government — — 4 — 4 — Foreign government 11 — — — 11 — Government-sponsored enterprises 26 1 51 — 77 1 Total $ 340 $ 4 $ 183 $ 3 $ 523 $ 7
Contractual Maturity Dates For Fixed-Maturity And Short-Term Investments	Contractual maturity dates for fixed-maturity investments were: (Dollars in millions) Amortized cost Fair % of fair value At December 31, 2020 Maturity dates: Due in one year or less $ 581 $ 589 4.8 % Due after one year through five years 3,450 3,697 30.0 Due after five years through ten years 3,789 4,178 33.9 Due after ten years 3,492 3,874 31.3 Total $ 11,312 $ 12,338 100.0 %
Investment Income, Realized Investment Gains And Losses And Change In Unrealized Investment Gains And Losses	The following table provides investment income and investment gains and losses: (Dollars in millions) Years ended December 31, 2020 2019 2018 Investment income: Interest $ 455 $ 446 $ 445 Dividends 220 201 181 Other 8 12 5 Total 683 659 631 Less investment expenses 13 13 12 Total $ 670 $ 646 $ 619 Investment gains and losses, net: Equity securities: Investment gains and losses on securities sold, net $ 79 $ 26 $ 9 Unrealized gains and losses on securities still held, net 841 1,626 (404) Subtotal 920 1,652 (395) Fixed-maturity securities: Gross realized gains 16 13 12 Gross realized losses (3) (3) (2) Write-down of impaired securities (78) (9) (5) Subtotal (65) 1 5 Other 10 (3) (12) Total $ 865 $ 1,650 $ (402)

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2020
Fair Value Hierarchy for Assets Measured at Fair Value on a Recurring Basis	The following tables illustrate the fair value hierarchy for those assets measured at fair value on a recurring basis at December 31, 2020 and 2019. We do not have any liabilities carried at fair value. There were no transfers between Level 1 and Level 2. (Dollars in millions) Quoted prices in Significant At December 31, 2020 Significant other Total Fixed maturities, available for sale: Corporate $ — $ 6,895 $ — $ 6,895 States, municipalities and political subdivisions — 4,997 — 4,997 Commercial mortgage-backed — 285 — 285 United States Government 120 — — 120 Foreign government — 29 — 29 Government-sponsored enterprises — 12 — 12 Subtotal 120 12,218 — 12,338 Common equities 8,541 — — 8,541 Nonredeemable preferred equities — 315 — 315 Separate accounts taxable fixed maturities — 903 — 903 Top Hat savings plan mutual funds and common 51 — — 51 Total $ 8,712 $ 13,436 $ — $ 22,148 At December 31, 2019 Fixed maturities, available for sale: Corporate $ — $ 6,401 $ — $ 6,401 States, municipalities and political subdivisions — 4,728 — 4,728 Commercial mortgage-backed — 301 — 301 United States Government 104 — — 104 Foreign government — 28 — 28 Government-sponsored enterprises — 136 — 136 Subtotal 104 11,594 — 11,698 Common equities 7,518 — — 7,518 Nonredeemable preferred equities — 234 — 234 Separate accounts taxable fixed maturities — 855 — 855 Top Hat savings plan mutual funds and common 45 — — 45 Total $ 7,667 $ 12,683 $ — $ 20,350
Fair Value of Life Policy Loans	The following table shows the fair value of our life policy loans, included in other invested assets: (Dollars in millions) Quoted prices in Significant other Significant Total At December 31, 2020 Life policy loans $ — $ — $ 49 $ 49 At December 31, 2019 Life policy loans $ — $ — $ 44 $ 44
Deferred Annuities and Structured Settlements
Fair Values of Deferred Annuities, Structured Settlements and Other Items	The following table shows fair value of our deferred annuities and structured settlements included in life policy and investment contract reserves: (Dollars in millions) Quoted prices in Significant other Significant Total At December 31, 2020 Deferred annuities $ — $ — $ 836 $ 836 Structured settlements — 227 — 227 Total $ — $ 227 $ 836 $ 1,063 At December 31, 2019 Deferred annuities $ — $ — $ 770 $ 770 Structured settlements — 212 — 212 Total $ — $ 212 $ 770 $ 982
Debt
Fair Values of Deferred Annuities, Structured Settlements and Other Items	The following table shows fair values of our note payable and long-term debt: (Dollars in millions) Quoted prices in Significant other Significant Total At December 31, 2020 Note payable $ — $ 54 $ — $ 54 6.900% senior debentures, due 2028 — 35 — 35 6.920% senior debentures, due 2028 — 515 — 515 6.125% senior notes, due 2034 — 522 — 522 Total $ — $ 1,126 $ — $ 1,126 At December 31, 2019 Note payable $ — $ 39 $ — $ 39 6.900% senior debentures, due 2028 — 34 — 34 6.920% senior debentures, due 2028 — 506 — 506 6.125% senior notes, due 2034 — 512 — 512 Total $ — $ 1,091 $ — $ 1,091

Property Casualty Loss and Lo_2

Property Casualty Loss and Loss Expenses (Tables)	12 Months Ended
	Dec. 31, 2020
Insurance [Abstract]
Consolidated Property Casualty Loss And Loss Expense Reserves	This table summarizes activity for our consolidated property casualty loss and loss expense reserves: (Dollars in millions) Years ended December 31, 2020 2019 2018 Gross loss and loss expense reserves, January 1 $ 6,088 $ 5,646 $ 5,219 Less reinsurance recoverable 342 238 187 Net loss and loss expense reserves, January 1 5,746 5,408 5,032 Net loss and loss expense reserves related to acquisition of Cincinnati Global at — 246 — Net incurred loss and loss expenses related to: Current accident year 3,968 3,600 3,390 Prior accident years (131) (248) (167) Total incurred 3,837 3,352 3,223 Net paid loss and loss expenses related to: Current accident year 1,493 1,462 1,391 Prior accident years 1,690 1,798 1,456 Total paid 3,183 3,260 2,847 Net loss and loss expense reserves, December 31 6,400 5,746 5,408 Plus reinsurance recoverable 277 342 238 Gross loss and loss expense reserves, December 31 $ 6,677 $ 6,088 $ 5,646
Reconciliation of Property casualty Incurred Losses and ALAE and Paid Losses and ALAE Development Information	The following table provides a reconciliation of the property casualty incurred losses and allocated loss adjustment expenses (ALAE) development and paid losses and ALAE development information at December 31, 2020. (Dollars in millions) Cumulative incurred losses Cumulative paid losses and ALAE as reported within the triangles, Liabilities for loss and ALAE for accident years not presented in the triangles, net of reinsurance Total liabilities for loss and ALAE, net of reinsurance Reinsurance recoverable on unpaid losses Total liabilities for gross loss and loss expense reserves Commercial casualty $ 5,179 $ 3,012 $ 91 $ 2,258 $ 24 $ 2,282 Workers' compensation 1,990 1,357 308 941 61 1,002 Commercial auto 2,235 1,581 26 680 5 685 Commercial property 3,158 2,725 15 448 66 514 Personal auto 1,860 1,610 10 260 32 292 Homeowner 1,996 1,781 4 219 18 237 Excess and surplus 836 430 1 407 16 423 Other lines 959 Total liabilities for loss and ALAE reserves 6,394 Unallocated loss adjustment expense reserves 283 Gross loss and loss expense reserves $ 6,677
Schedule of Incurred and Paid Losses and ALAE Development by Accident Year	The following table shows the commercial casualty incurred and paid losses and ALAE development by accident year. The table also shows the IBNR reserves plus expected development on reported losses and claim frequency: (Dollars in millions, reported claims in thousands) As of December 31, 2020 Incurred losses and ALAE, net of reinsurance for the years ended December 31, Total of incurred Cumulative number of Accident Unaudited Year 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2011 $ 466 $ 404 $ 377 $ 377 $ 375 $ 380 $ 366 $ 365 $ 368 $ 361 $ — 19 2012 466 414 417 394 394 404 399 397 397 11 18 2013 448 443 431 416 413 407 391 386 22 20 2014 503 496 479 476 479 465 469 27 21 2015 533 526 529 516 508 502 54 21 2016 563 574 557 555 554 89 21 2017 610 597 577 571 124 21 2018 650 641 622 181 22 2019 672 643 293 19 2020 674 472 11 Total $ 5,179 Cumulative paid losses and ALAE, net of reinsurance 2011 $ 27 $ 93 $ 149 $ 227 $ 266 $ 298 $ 315 $ 325 $ 337 $ 342 2012 27 88 170 232 288 330 346 364 374 2013 35 90 159 232 286 312 337 348 2014 34 97 172 287 338 390 409 2015 38 108 200 287 362 404 2016 46 126 228 331 395 2017 48 122 234 320 2018 44 148 253 2019 39 134 2020 33 Total 3,012 All outstanding liabilities before 2011, net of reinsurance 91 Liabilities for loss and ALAE, net of reinsurance $ 2,258 The following table shows the workers’ compensation incurred and paid losses and ALAE development by accident year. The table also shows the IBNR reserves plus expected development on reported losses and claim frequency: (Dollars in millions, reported claims in thousands) As of December 31, 2020 Incurred losses and ALAE, net of reinsurance for the years ended December 31, Total of incurred Cumulative number of Accident Unaudited Year 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2011 $ 284 $ 251 $ 246 $ 242 $ 239 $ 236 $ 231 $ 229 $ 228 $ 228 $ 17 24 2012 265 245 234 220 213 211 209 208 207 19 21 2013 264 246 221 212 208 205 202 201 12 20 2014 261 233 214 203 201 198 197 13 19 2015 246 220 208 195 179 173 26 17 2016 230 218 206 188 183 27 16 2017 218 208 190 183 46 15 2018 222 207 199 52 15 2019 224 215 65 14 2020 204 100 10 Total $ 1,990 Cumulative paid losses and ALAE, net of reinsurance 2011 $ 65 $ 131 $ 161 $ 177 $ 186 $ 190 $ 192 $ 195 $ 197 $ 198 2012 62 121 147 162 171 175 178 180 182 2013 61 119 144 157 164 168 170 174 2014 56 110 134 148 157 162 165 2015 47 93 115 129 134 137 2016 46 97 119 131 141 2017 45 88 106 114 2018 48 95 115 2019 49 94 2020 37 Total 1,357 All outstanding liabilities before 2011, net of reinsurance 308 Liabilities for loss and ALAE, net of reinsurance $ 941 The following table shows the commercial auto incurred and paid losses and ALAE development by accident year. The table also shows the IBNR reserves plus expected development on reported losses and claim frequency: (Dollars in millions, reported claims in thousands) As of December 31, 2020 Incurred losses and ALAE, net of reinsurance for the years ended December 31, Total of incurred Cumulative number of reported claims Accident Unaudited Year 2016 2017 2018 2019 2020 2016 $ 417 $ 430 $ 450 $ 463 $ 474 $ 5 53 2017 451 441 443 444 13 51 2018 453 442 442 36 49 2019 452 451 73 46 2020 424 164 33 Total $ 2,235 Cumulative paid losses and ALAE, net of reinsurance 2016 $ 184 $ 273 $ 350 $ 408 $ 441 2017 187 266 334 381 2018 184 266 337 2019 183 268 2020 154 Total 1,581 All outstanding liabilities before 2016, net of reinsurance 26 Liabilities for loss and ALAE, net of reinsurance $ 680 The following table shows the commercial property incurred and paid losses and ALAE development by accident year. The table also shows the IBNR reserves plus expected development on reported losses and claim frequency: (Dollars in millions, reported claims in thousands) As of December 31, 2020 Incurred losses and ALAE, net of reinsurance for the years ended December 31, Total of incurred Cumulative number of reported claims Accident Unaudited Year 2016 2017 2018 2019 2020 2016 $ 590 $ 551 $ 541 $ 545 $ 542 $ 2 17 2017 587 560 556 565 3 18 2018 630 603 590 7 18 2019 621 606 6 17 2020 855 141 22 Total $ 3,158 Cumulative paid losses and ALAE, net of reinsurance 2016 $ 358 $ 504 $ 528 $ 539 $ 539 2017 395 522 547 560 2018 386 559 576 2019 413 561 2020 489 Total 2,725 All outstanding liabilities before 2016, net of reinsurance 15 Liabilities for loss and ALAE, net of reinsurance $ 448 The following table shows the personal auto incurred and paid losses and ALAE development by accident year. The table also shows the IBNR reserves plus expected development on reported losses and claim frequency: (Dollars in millions, reported claims in thousands) As of December 31, 2020 Incurred losses and ALAE, net of reinsurance for the years ended December 31, Total of incurred Cumulative number of reported claims Accident Unaudited Year 2016 2017 2018 2019 2020 2016 $ 383 $ 384 $ 386 $ 384 $ 384 $ 1 110 2017 412 394 391 393 1 109 2018 424 398 395 1 111 2019 399 383 14 102 2020 305 62 67 Total $ 1,860 Cumulative paid losses and ALAE, net of reinsurance 2016 $ 243 $ 316 $ 351 $ 370 $ 378 2017 256 324 358 374 2018 262 327 358 2019 250 314 2020 186 Total 1,610 All outstanding liabilities before 2016, net of reinsurance 10 Liabilities for loss and ALAE, net of reinsurance $ 260 The following table shows the homeowner incurred and paid losses and ALAE development by accident year. The table also shows the IBNR reserves plus expected development on reported losses and claim frequency: (Dollars in millions, reported claims in thousands) As of December 31, 2020 Incurred losses and ALAE, net of reinsurance for the years ended December 31, Total of incurred Cumulative number of reported claims Accident Unaudited Year 2016 2017 2018 2019 2020 2016 $ 315 $ 304 $ 303 $ 302 $ 304 $ — 23 2017 356 383 385 387 — 26 2018 370 386 387 5 24 2019 432 421 10 22 2020 497 54 21 Total $ 1,996 Cumulative paid losses and ALAE, net of reinsurance 2016 $ 208 $ 283 $ 295 $ 299 $ 302 2017 277 356 378 384 2018 268 368 378 2019 303 391 2020 326 Total 1,781 All outstanding liabilities before 2016, net of reinsurance 4 Liabilities for loss and ALAE, net of reinsurance $ 219 The following table shows the excess and surplus lines incurred and paid losses and ALAE development by accident year. The table also shows the IBNR reserves plus expected development on reported losses and claim frequency: (Dollars in millions, reported claims in thousands) As of December 31, 2020 Incurred losses and ALAE, net of reinsurance for the years ended December 31, Total of incurred Cumulative number of reported claims Accident Unaudited Year 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2011 $ 48 $ 47 $ 44 $ 38 $ 36 $ 35 $ 35 $ 34 $ 34 $ 34 $ — 1 2012 67 56 49 40 37 36 35 36 35 — 1 2013 74 64 54 45 42 41 41 41 2 2 2014 95 82 75 64 60 59 59 5 2 2015 96 81 73 67 65 66 6 2 2016 93 87 84 82 90 13 3 2017 104 95 95 94 15 3 2018 116 109 110 29 3 2019 137 135 50 3 2020 172 $ 105 2 Total $ 836 Cumulative paid losses and ALAE, net of reinsurance 2011 $ 8 $ 14 $ 23 $ 27 $ 30 $ 32 $ 34 $ 33 $ 33 $ 33 2012 9 15 19 25 29 31 32 33 34 2013 7 12 20 27 32 34 37 39 2014 9 17 27 37 43 48 51 2015 8 19 29 41 51 54 2016 10 21 39 51 62 2017 11 23 41 57 2018 11 26 50 2019 13 34 2020 16 Total 430 All outstanding liabilities before 2011, net of reinsurance 1 Liabilities for loss and ALAE, net of reinsurance $ 407
Schedule of Average Annual Percentage Payout of Incurred Claims	The following table shows the average annual percentage payout of incurred losses for the commercial casualty line of business: Average annual percentage payout of incurred losses by age, net of reinsurance (unaudited) Years 1 2 3 4 5 6 7 8 9 10 Average annual percentage payout 7.3% 14.9% 17.9% 18.8% 12.7% 9.1% 4.8% 3.5% 3.0% 1.7% The following table shows the average annual percentage payout of incurred losses for the workers’ compensation line of business: Average annual percentage payout of incurred losses by age, net of reinsurance (unaudited) Years 1 2 3 4 5 6 7 8 9 10 Average annual percentage payout 25.9% 26.3% 11.9% 6.7% 4.1% 2.0% 1.4% 1.2% 1.1% 0.5% The following table shows the average annual percentage payout of incurred losses for the commercial auto line of business. Commercial auto includes both physical damage and liability losses. A majority of the incurred losses paid after year 2 are the result of liability losses. Average annual percentage payout of incurred losses by age, net of reinsurance (unaudited) Years 1 2 3 4 5 Average annual percentage payout 39.9% 18.6% 15.8% 11.5% 7.0% The following table shows the average annual percentage payout of incurred losses for the commercial property line of business: Average annual percentage payout of incurred losses by age, net of reinsurance (unaudited) Years 1 2 3 4 5 Average annual percentage payout 65.3% 25.8% 3.9% 2.1% 0.1% The following table shows the average annual percentage payout of incurred losses for the personal auto line of business. Personal auto includes both physical damage and liability losses. A majority of the incurred losses paid after year 2 are the result of liability losses. Average annual percentage payout of incurred losses by age, net of reinsurance (unaudited) Years 1 2 3 4 5 Average annual percentage payout 64.2% 17.3% 8.6% 4.6% 2.0% The following table shows the average annual percentage payout of incurred losses for the homeowner line of business: Average annual percentage payout of incurred losses by age, net of reinsurance (unaudited) Years 1 2 3 4 5 Average annual percentage payout 69.3% 23.0% 4.1% 1.4% 0.8% The following table shows the average annual percentage payout of incurred losses for the excess and surplus lines insurance segment. Excess and surplus lines consist mostly of commercial casualty and commercial property coverages. A majority of the incurred losses paid after year 2 are the result of commercial casualty losses. Average annual percentage payout of incurred losses by age, net of reinsurance (unaudited) Years 1 2 3 4 5 6 7 8 9 10 Average annual percentage payout 14.6% 14.4% 19.2% 15.4% 11.7% 6.9% 3.9% 2.2% 1.0% 0.2%

Life Policy And Investment Co_2

Life Policy And Investment Contract Reserves (Tables)	12 Months Ended
	Dec. 31, 2020
Liability for Future Policy Benefit, before Reinsurance [Abstract]
Reserve In Addition To The Account Balance, Based on Expected No-Lapse Guarantee Benefits And Expected Policy Assessments	This table summarizes our life policy and investment contract reserves: (Dollars in millions) At December 31, 2020 2019 Life policy reserves: Ordinary/traditional life $ 1,301 $ 1,226 Other 52 50 Subtotal 1,353 1,276 Investment contract reserves: Deferred annuities 761 760 Universal life 647 640 Structured settlements 145 151 Other 9 8 Subtotal 1,562 1,559 Total life policy and investment contract reserves $ 2,915 $ 2,835

Deferred Policy Acquisition C_2

Deferred Policy Acquisition Costs (Tables)	12 Months Ended
	Dec. 31, 2020
Deferred Costs [Abstract]
Deferred Policy Acquisition Costs And Asset Reconciliation, Including the Amortized Deferred Policy Acquisition Costs	The table below shows the deferred policy acquisition costs and asset reconciliation: (Dollars in millions) Years ended December 31, 2020 2019 2018 Property casualty: Deferred policy acquisition costs asset, January 1 $ 512 $ 464 $ 438 Capitalized deferred policy acquisition costs 1,087 1,034 933 Amortized deferred policy acquisition costs (1,057) (986) (907) Deferred policy acquisition costs asset, December 31 $ 542 $ 512 $ 464 Life: Deferred policy acquisition costs asset, January 1 $ 262 $ 274 $ 232 Capitalized deferred policy acquisition costs 58 61 60 Amortized deferred policy acquisition costs (49) (48) (39) Shadow deferred policy acquisition costs (8) (25) 21 Deferred policy acquisition costs asset, December 31 $ 263 $ 262 $ 274 Consolidated: Deferred policy acquisition costs asset, January 1 $ 774 $ 738 $ 670 Capitalized deferred policy acquisition costs 1,145 1,095 993 Amortized deferred policy acquisition costs (1,106) (1,034) (946) Shadow deferred policy acquisition costs (8) (25) 21 Deferred policy acquisition costs asset, December 31 $ 805 $ 774 $ 738

Long-Term Debt And Lease Obli_2

Long-Term Debt And Lease Obligation (Tables)	12 Months Ended
	Dec. 31, 2020
Long-term Debt and Lease Obligation [Abstract]
Book Value And Principal Amounts Of Long-Term Debt	This table summarizes the principal amounts of our long-term debt excluding unamortized discounts, none of which are encumbered by rating triggers: (Dollars in millions) Book value Principal amount Interest rate Year of At December 31, At December 31, 2020 2019 2020 2019 6.900% 1998 Senior debentures, due 2028 $ 27 $ 27 $ 28 $ 28 6.920% 2005 Senior debentures, due 2028 391 391 391 391 6.125% 2004 Senior notes, due 2034 370 370 374 374 Total $ 788 $ 788 $ 793 $ 793
Capital Lease Payments Over Next Five Years	interest for finance and operating leases: (Dollars in millions) Years ended December 31, 2021 2022 2023 2024 2025 2026 and thereafter Finance lease obligations $ 15 $ 12 $ 10 $ 6 $ 4 $ 2 Operating lease obligations 2 2 2 2 1 2 Total lease obligations $ 17 $ 14 $ 12 $ 8 $ 5 $ 4
Other Operating and Finance Lease Disclosure [Table Text Block]	The following table provides lease cost and other information for the year ended December 31, 2020 and 2019: (Dollars in millions) 2020 2019 Lease cost: Finance lease cost $ 15 $ 9 Operating lease cost 4 4 Total lease cost $ 19 $ 13 Other information finance leases: Finance cash outflows $ 15 $ 15 Weighted average discount rate 2.62 % 2.96 % Weighted average remaining lease term in years 3.67 3.65 Other information operating leases: Operating cash outflows $ 8 $ 8 Weighted average discount rate 3.65 % 3.69 % Weighted average remaining lease term in years 4.84 4.71

Shareholders' Equity And Divi_2

Shareholders' Equity And Dividend Restrictions (Tables)	12 Months Ended
	Dec. 31, 2020
Shareholders Equity And Dividend Restrictions [Abstract]
Change In AOCI Includes Changes In Unrealized Gains And Losses On Investments And Pension Obligations	The changes from the beginning of year to the end of year are the result of changes to other comprehensive income or loss (OCI). (Dollars in millions) 2020 2019 2018 Before Income Net Before Income Net Before Income Net Investments: AOCI, January 1 $ 590 $ 123 $ 467 $ 46 $ 9 $ 37 $ 3,540 $ 733 $ 2,807 Cumulative effect of change in accounting for equity securities as of January 1, 2018 — — — — — — (3,155) (652) (2,503) Adjusted AOCI, beginning of period 590 123 467 46 9 37 385 81 304 OCI before investment gains and losses, net, recognized in net income 371 78 293 545 115 430 (334) (71) (263) Investment gains and losses, net, recognized in net income 65 14 51 (1) (1) — (5) (1) (4) OCI 436 92 344 544 114 430 (339) (72) (267) AOCI, December 31 $ 1,026 $ 215 $ 811 $ 590 $ 123 $ 467 $ 46 $ 9 $ 37 Pension obligations: AOCI, January 1 $ (9) $ — $ (9) $ (16) $ (2) $ (14) $ (12) $ (1) $ (11) OCI excluding amortization recognized in net income (35) (7) (28) 6 2 4 (5) (1) (4) Amortization recognized in net income 3 — 3 1 — 1 1 — 1 OCI (32) (7) (25) 7 2 5 (4) (1) (3) AOCI, December 31 $ (41) $ (7) $ (34) $ (9) $ — $ (9) $ (16) $ (2) $ (14) Life deferred acquisition costs, life policy reserves and other: AOCI, January 1 $ (13) $ (3) $ (10) $ (1) $ — $ (1) $ (10) $ (2) $ (8) OCI before investment gains and losses, net, recognized in net income 3 1 2 (15) (3) (12) (3) (1) (2) Investment gains and losses, net, recognized in net income — — — 3 — 3 12 3 9 OCI 3 1 2 (12) (3) (9) 9 2 7 AOCI, December 31 $ (10) $ (2) $ (8) $ (13) $ (3) $ (10) $ (1) $ — $ (1) Summary of AOCI: AOCI, January 1 $ 568 $ 120 $ 448 $ 29 $ 7 $ 22 $ 3,518 $ 730 $ 2,788 Cumulative effect of change in accounting for equity securities as of January 1, 2018 — — — — — — (3,155) (652) (2,503) Adjusted AOCI, beginning of period 568 120 448 29 7 22 363 78 285 Investments OCI 436 92 344 544 114 430 (339) (72) (267) Pension obligations OCI (32) (7) (25) 7 2 5 (4) (1) (3) Life deferred acquisition costs, life policy reserves and other OCI 3 1 2 (12) (3) (9) 9 2 7 Total OCI 407 86 321 539 113 426 (334) (71) (263) AOCI, December 31 $ 975 $ 206 $ 769 $ 568 $ 120 $ 448 $ 29 $ 7 $ 22

Reinsurance (Tables)

Reinsurance (Tables)	12 Months Ended
	Dec. 31, 2020
Reinsurance Disclosures [Abstract]
Property Casualty Insurance Assumed And Ceded Business	The table below summarizes our consolidated property casualty insurance net written premiums, earned premiums and incurred loss and loss expenses: (Dollars in millions) Years ended December 31, 2020 2019 2018 Direct written premiums $ 5,756 $ 5,477 $ 5,018 Assumed written premiums 335 244 173 Ceded written premiums (227) (205) (161) Net written premiums $ 5,864 $ 5,516 $ 5,030 Direct earned premiums $ 5,623 $ 5,340 $ 4,931 Assumed earned premiums 285 199 149 Ceded earned premiums (217) (205) (160) Earned premiums $ 5,691 $ 5,334 $ 4,920 Direct incurred loss and loss expenses $ 3,699 $ 3,402 $ 3,188 Assumed incurred loss and loss expenses 184 117 125 Ceded incurred loss and loss expenses (46) (167) (90) Incurred loss and loss expenses $ 3,837 $ 3,352 $ 3,223
Life Insurance Assumed And Ceded Business	The table below summarizes our consolidated life insurance earned premiums and contract holders' benefits incurred: (Dollars in millions) Years ended December 31, 2020 2019 2018 Direct earned premiums $ 362 $ 341 $ 320 Ceded earned premiums (73) (71) (70) Earned premiums $ 289 $ 270 $ 250 Direct contract holders' benefits incurred $ 359 $ 359 $ 328 Ceded contract holders' benefits incurred (62) (73) (61) Contract holders' benefits incurred $ 297 $ 286 $ 267

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Components Of Deferred Tax Assets And Liabilities	The significant components of deferred tax assets and liabilities included in the consolidated balance sheets at December 31 were as follows: (Dollars in millions) At December 31, 2020 2019 Deferred tax assets: Unearned premiums $ 119 $ 113 Loss and loss expense reserves 81 66 Deferred international earnings 45 51 Net operating loss on international earnings 26 4 Other 41 39 Deferred tax assets before valuation allowance 312 273 Valuation allowance for international operations 56 41 Deferred tax assets net of valuation allowance 256 232 Deferred tax liabilities: Investment gains and other, net 1,240 995 Deferred acquisition costs 143 139 Life policy reserves 121 120 Investments 13 23 Other 38 34 Total gross deferred tax liabilities 1,555 1,311 Net deferred income tax liability $ 1,299 $ 1,079
Schedule of Income before Income Tax	For financial reporting purposes, income (loss) before income taxes includes the following components: (Dollars in millions) For the years ended December 31, 2020 2019 2018 United States $ 1,521 $ 2,440 $ 251 International (22) 32 — Total income before income taxes $ 1,499 $ 2,472 $ 251
Schedule of The Provision (Benefit) of Income Taxes	The provision (benefit) for income taxes consists of: (Dollars in millions) For the years ended December 31, 2020 2019 2018 Provision (benefit) for income taxes: Current – United States federal $ 147 $ 137 $ 11 International — (5) — Total current 147 132 11 Deferred – United States federal 136 338 (47) International — 5 — Total deferred 136 343 (47) Total provision (benefit) for income taxes $ 283 $ 475 $ (36)
Differences Between The 35 Percent Statutory Income Tax Rate And Effective Income Tax Rate	The differences between the 21% statutory federal income tax rate and our effective income tax rate were as follows: (Dollars in millions) Years ended December 31, 2020 2019 2018 Tax at statutory rate: $ 315 21.0 % $ 519 21.0 % $ 53 21.0 % Increase (decrease) resulting from: Tax-exempt income from municipal bonds (20) (1.3) (19) (0.8) (20) (8.0) Dividend received exclusion (17) (1.1) (16) (0.6) (15) (6.0) Tax accounting method changes — — — — (50) (19.9) Other 5 0.3 (9) (0.4) (4) (1.4) Provision (benefit) for income taxes $ 283 18.9 % $ 475 19.2 % $ (36) (14.3) %
Reconciliation of Unrecognized Tax Benefits	The following is a tabular reconciliation of the total amounts of unrecognized tax benefits. (Dollars in millions) Years ended December 31, 2020 2019 2018 Gross unrecognized tax benefits, January 1 $ 34 $ 34 $ — Gross increase in prior year positions — — — Gross decrease in prior year positions — — — Gross increase in current year positions — — 34 Settlements with tax authorities — — — Lapse of statute of limitations — — — Gross unrecognized tax benefits, December 31 $ 34 $ 34 $ 34
Reconciliation of Cincinnati Global Valuation Allowance	The following is a tabular reconciliation of the total amounts of our Cincinnati Global valuation allowance. (Dollars in millions) Years ended December 31, 2020 2019 Valuation allowance, January 1 $ 41 $ — Acquisition accounting amount — 55 Current year operations 15 (14) Valuation allowance, December 31 $ 56 $ 41

Net Income Per Common Share (Ta

Net Income Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Calculations For Basic And Diluted Earnings Per Share	The table shows calculations for basic and diluted earnings per share: (In millions, except per share data) Years ended December 31, 2020 2019 2018 Numerator: Net income—basic and diluted $ 1,216 $ 1,997 $ 287 Denominator: Basic weighted-average common shares outstanding 161.2 163.2 163.2 Effect of share-based awards: Stock options 0.7 1.2 0.8 Nonvested shares 0.5 0.7 0.5 Diluted weighted-average shares 162.4 165.1 164.5 Earnings per share: Basic $ 7.55 $ 12.24 $ 1.76 Diluted 7.49 12.10 1.75 Number of anti-dilutive share-based awards 1.4 — 1.3

Employee Retirement Benefits (T

Employee Retirement Benefits (Tables)	12 Months Ended
	Dec. 31, 2020
Weighted-Average Assumptions Used for Benefit Obligations	This is a summary of the weighted-average assumptions used to determine our benefit obligations at December 31 for the plans: Qualified Pension Plan SERP 2020 2019 2020 2019 Discount rate 2.68 % 3.40 % 2.52 % 3.33 % Rate of compensation increase 2.25-3.25 2.25-3.25 2.25-3.25 2.25-3.25
Assumptions of Net Benefit Costs	This is a summary of the weighted-average assumptions used to determine our net periodic benefit cost for the plans: Qualified Pension Plan SERP 2020 2019 2018 2020 2019 2018 Discount rate 3.40 % 4.34 % 3.73 % 3.33 % 4.25 % 3.61 % Expected return on plan assets 7.00 7.00 7.25 n/a n/a n/a Rate of compensation increase 2.25-3.25 2.25-3.25 2.75-3.25 2.25-3.25 2.25-3.25 2.75-3.25
Benefit Obligation Activity Using An Actuarial Measurement Date For Qualified Plan And SERP	Benefit obligation activity using an actuarial measurement date for our qualified pension plan and SERP at December 31 follows: (Dollars in millions) At December 31, 2020 2019 Change in projected benefit obligation: Benefit obligation, January 1 $ 350 $ 318 Service cost 9 8 Interest cost 12 13 Actuarial loss 51 45 Benefits paid (35) (34) Projected benefit obligation, December 31 $ 387 $ 350 Change in plan assets: Fair value of plan assets, January 1 $ 354 $ 318 Actual return on plan assets 34 70 Employer contribution 4 — Benefits paid (35) (34) Fair value of plan assets, December 31 $ 357 $ 354 Funded status, December 31 $ (30) $ 4 Accumulated benefit obligation $ 360 $ 327
Reconciliation Of The Funded Status For Qualified Plan And SERP	A reconciliation follows of the funded status for our qualified plan and SERP at the end of the measurement period to the amounts recognized in the consolidated balance sheets at December 31: (Dollars in millions) At December 31, 2020 2019 Pension amounts recognized in the consolidated balance sheets: Other (liability) assets $ (30) $ 4 Total $ (30) $ 4 Pension amounts recognized in accumulated other comprehensive income: Net actuarial loss $ 41 $ 9 Total $ 41 $ 9
Components Of Net Periodic Benefit Cost As Well As Other Changes In Plan Assets And Benefit Obligations Recognized In Other Comprehensive Income For Qualified Plan And SERP	Below are the components of our net periodic benefit cost, as well as other changes in plan assets and benefit obligations recognized in other comprehensive income for our qualified plan and SERP at December 31: (Dollars in millions) Years ended December 31, 2020 2019 2018 Net periodic benefit cost: Service cost $ 9 $ 8 $ 11 Non-service costs (benefit): Interest cost 12 13 13 Expected return on plan assets (21) (20) (22) Amortization of actuarial loss and prior service cost 3 1 1 Other 3 1 2 Net periodic benefit cost $ 6 $ 3 $ 5 Other changes in plan assets and benefit obligations recognized in other Current year actuarial (gain) loss $ 38 $ (5) $ 7 Amortization of actuarial loss (6) (2) (3) Total recognized in other comprehensive (income) loss $ 32 $ (7) $ 4 Total recognized in net periodic benefit cost and other comprehensive $ 38 $ (4) $ 9
Fair Value Hierarchy Of Assets Measured At Fair Value On A Recurring Basis	(Dollars in millions) Quoted prices in Significant other Significant Total At December 31, 2020 Fixed maturities, available for sale: United States Government $ 31 $ — $ — $ 31 Corporate — 20 — 20 States, municipalities and political subdivisions — 9 — 9 Total fixed maturities, available for sale 31 29 — 60 Common equities 266 — — 266 Total $ 297 $ 29 $ — $ 326 At December 31, 2019 Fixed maturities, available for sale: United States Government $ 25 $ — $ — $ 25 Corporate — 27 — 27 States, municipalities and political subdivisions — 25 — 25 Total fixed maturities, available for sale 25 52 — 77 Common equities 260 — — 260 Total $ 285 $ 52 $ — $ 337
Expected Future Benefit Payments For Qualified Plan And SERP	We expect to make the following benefit payments for our qualified plan and SERP, reflecting expected future service: (Dollars in millions) Years ended December 31, 2021 2022 2023 2024 2025 2026 - 2030 Expected future benefit payments $ 49 $ 22 $ 25 $ 27 $ 29 $ 163

Statutory Accounting Informat_2

Statutory Accounting Information (Tables)	12 Months Ended
	Dec. 31, 2020
Staturory Accounting Information [Abstract]
Statutory Net Income And Statutory Surplus	The statutory net income and statutory capital and surplus are presented below: (Dollars in millions) Net income Capital and surplus Years ended December 31, At December 31, 2020 2019 2018 2020 2019 The Cincinnati Insurance Company $ 466 $ 558 $ 626 $ 5,838 $ 5,620 The Cincinnati Casualty Company 14 13 16 456 437 The Cincinnati Indemnity Company 3 3 5 115 111 The Cincinnati Specialty Underwriters Insurance Company 42 62 69 528 526 The Cincinnati Life Insurance Company 27 19 — 241 204

Share-Based Associate Compens_2

Share-Based Associate Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award
Stock Option Information	Below is a summary of option information for the year 2020: (Dollars in millions, except exercise price. Shares in thousands) Shares Weighted- Aggregate Weighted-average Outstanding option shares at January 1, 2020 3,437 $ 63.99 Granted 508 111.53 Exercised (274) 41.86 Forfeited or expired (70) 55.60 Outstanding option shares at December 31, 2020 3,601 72.55 $ 66 6.01 years Options exercisable at end of period 2,509 $ 63.11 $ 61 4.97 years
Restricted Stock Unit Information	elow is a summary of service-based and performance-based share information, assuming a target payout for performance-based shares, for the year 2020: (Shares in thousands) Service-based Weighted- Performance-based Weighted- Nonvested at January 1, 2020 783 $ 70.27 165 $ 64.23 Granted 204 104.81 38 111.77 Vested (269) 66.53 (56) 43.26 Forfeited or canceled (22) 78.96 — — Nonvested at December 31, 2020 696 81.56 147 84.64
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award
Assumptions Used In Option Grants Issued	The following weighted average assumptions were used in determining fair value for option grants issued: 2020 2019 2018 Weighted-average expected term 7-8 years 7-8 years 7-8 years Expected volatility 16.89-17.13% 14.49-15.39% 15.04-15.10% Dividend yield 2.15% 2.61% 2.98% Risk-free rates 1.40-1.41% 2.62-2.64% 2.77-2.83% Weighted-average fair value of options granted during the period $15.45 $11.73 $9.87
Performance Based Shares
Share-based Compensation Arrangement by Share-based Payment Award
Assumptions Used In Option Grants Issued	he following assumptions were used in determining fair value for performance-based grants issued: 2020 2019 2018 Expected term 2.86 years 2.86 years 2.89 years Expected volatility 15.88-25.13% 15.10-25.00% 16.01-26.32% Dividend yield 2.15% 2.61% 2.81% Risk-free rates 1.30% 2.48% 2.22%

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2020
Segment Reporting [Abstract]
Segment Information	Segment information is summarized in the following table: (Dollars in millions) Years ended December 31, 2020 2019 2018 Revenues: Commercial lines insurance Commercial casualty $ 1,165 $ 1,102 $ 1,075 Commercial property 1,010 958 920 Commercial auto 755 707 664 Workers' compensation 271 300 324 Other commercial 275 252 235 Commercial lines insurance premiums 3,476 3,319 3,218 Fee revenues 3 5 5 Total commercial lines insurance 3,479 3,324 3,223 Personal lines insurance Personal auto 615 621 614 Homeowner 658 607 563 Other personal 190 176 159 Personal lines insurance premiums 1,463 1,404 1,336 Fee revenues 4 4 5 Total personal lines insurance 1,467 1,408 1,341 Excess and surplus lines insurance 325 278 234 Fee revenues 2 2 1 Total excess and surplus lines insurance 327 280 235 Life insurance premiums 289 270 250 Fee revenues 2 4 4 Total life insurance 291 274 254 Investments Investment income, net of expenses 670 646 619 Investment gains and losses, net 865 1,650 (402) Total investment revenue 1,535 2,296 217 Other Premiums 427 333 132 Other 10 9 5 Total other revenue 437 342 137 Total revenues $ 7,536 $ 7,924 $ 5,407 Income (loss) before income taxes: Insurance underwriting results Commercial lines insurance $ 64 $ 241 $ 151 Personal lines insurance 47 8 (20) Excess and surplus lines insurance 34 53 63 Life insurance 11 1 8 Investments 1,433 2,197 121 Other (90) (28) (72) Total income before income taxes $ 1,499 $ 2,472 $ 251 December 31, December 31, Identifiable assets: 2020 2019 Property casualty insurance $ 3,838 $ 3,437 Life insurance 1,661 1,516 Investments 21,332 19,583 Other 711 872 Total $ 27,542 $ 25,408

Quarterly Supplementary Data (T

Quarterly Supplementary Data (Tables)	12 Months Ended
	Dec. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Unaudited Quarterly Financial Information	This table includes unaudited quarterly financial information for the years ended December 31, 2020 and 2019: (Dollars in millions, except per share data) Quarter 1st 2nd 3rd 4th Full year 2020 Revenues $ (99) $ 2,714 $ 2,227 $ 2,694 $ 7,536 Income (loss) before income taxes (1,576) 1,145 614 1,316 1,499 Net income (loss) (1,226) 909 484 1,049 1,216 Net income (loss) per common share—basic (7.56) 5.65 3.01 6.52 7.55 Net income (loss) per common share—diluted (7.56) 5.63 2.99 6.47 7.49 2019 Revenues $ 2,159 $ 1,913 $ 1,700 $ 2,152 $ 7,924 Income before income taxes 867 530 294 781 2,472 Net income 695 428 248 626 1,997 Net income per common share—basic 4.27 2.62 1.51 3.84 12.24 Net income per common share—diluted 4.22 2.59 1.49 3.79 12.10

Summary Of Significant Accoun_3

Summary Of Significant Accounting Policies (Narrative) (Details)	Feb. 28, 2019	Dec. 31, 2020USD ($)independent_insurance_agencysubsidiarystatereporting_locations	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	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		1,848
Number of reporting locations | reporting_locations		2,578
Number of states in which entity operates | state		45
Excess (deficit) of Separate Account Fair Value over (under) Contract Holder Account Value		$ 99,000,000	$ 52,000,000
Minimum participant age to elect					40 years
Other invested assets		348,000,000	296,000,000
Depreciation expense		33,000,000	25,000,000	$ 31,000,000
Land, building and equipment impairments		0	0	$ 0
Increase to allowance through retained earnings for ASU 2016-13, after-tax			2,000,000
Covid-19 pandemic-related incurred loss and expenses		85,000,000
Premium Receivable, Allowance for Credit Loss		19,000,000
Premium Receivable, Allowance for Credit Loss, Property Casualty Premiums Receivable		$ 9,000,000
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		$ 33,000,000	32,000,000
Venture Capital Funds
Significant Accounting Policies
Other invested assets		128,000,000	71,000,000
Real Estate Investment
Significant Accounting Policies
Other invested assets		25,000,000	29,000,000
Other than Securities Investment
Significant Accounting Policies
Other invested assets		$ 162,000,000	$ 164,000,000
10 Largest States
Significant Accounting Policies
Generated percentage of total earned premiums		53.30%	54.80%
Ohio, Largest State
Significant Accounting Policies
Generated percentage of total earned premiums		14.80%	15.10%
Illinois, Georgia, North Carolina, Indiana and Pennsylvania | Minimum
Significant Accounting Policies
Generated percentage of total earned premiums		4.00%
Illinois, Georgia, North Carolina, Indiana and Pennsylvania | 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		1.30%
All Other | Maximum
Significant Accounting Policies
Generated percentage of total earned premiums		4.00%
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
Syndicate capacity - indefinite lived		$ 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

Investments (Narrative) (Detail

Investments (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)security	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Gain (Loss) on Investments
Largest single common stock holding	$ 644	$ 414
Largest equity holdings to total equity portfolio	7.50%	5.50%
Largest equity holdings to total portfolio	3.00%	2.10%
Assets Held by Insurance Regulators	$ 121	$ 117
Collateral at fair value	98	$ 95
Impaired securities		3	1
Available-for-sale securities, continuous unrealized loss position, 12 months or longer, aggregate loss		$ 3	$ 58
Equity securities, at fair value (cost: 2020—$3,927; 2019—$3,581)	$ 8,856	$ 7,752
Number of Impaired Securities with Allowance for Credit Losses | security	0
Fixed Maturities
Gain (Loss) on Investments
Number of securities total unrealized loss in an unrealized loss position for 12 months or more		38	400
Number of securities below 70 percent of amortized cost	0	0	0
Number Of Impaired Securities Intended to be Sold | security	14
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss 3	$ 10
Number Of Securities Continuous Unrealized Loss Position | security	128
Equity Securities | Common Stock
Gain (Loss) on Investments
Equity securities, at fair value (cost: 2020—$3,927; 2019—$3,581)	$ 8,541	$ 7,518

Investments (Analysis Of Cost O

Investments (Analysis Of Cost Or Amortized Cost Gross Unrealized Gains And Losses And Fair Value For Investments) (Details) - Fixed Maturities - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Schedule of Available-for-sale Securities
Cost or amortized cost	$ 11,312	$ 11,108
Gross unrealized gains	1,036	597
Gross unrealized losses	10	7
Fair value	12,338	11,698
Corporate Securities
Schedule of Available-for-sale Securities
Cost or amortized cost	6,281	6,074
Gross unrealized gains	621	332
Gross unrealized losses	7	5
Fair value	6,895	6,401
States, Municipalities and Political Subdivisions
Schedule of Available-for-sale Securities
Cost or amortized cost	4,604	4,477
Gross unrealized gains	395	252
Gross unrealized losses	2	1
Fair value	4,997	4,728
Commercial Mortgage Backed Securities
Schedule of Available-for-sale Securities
Cost or amortized cost	271	290
Gross unrealized gains	15	11
Gross unrealized losses	1	0
Fair value	285	301
United States Government
Schedule of Available-for-sale Securities
Cost or amortized cost	115	102
Gross unrealized gains	5	2
Gross unrealized losses	0	0
Fair value	120	104
Foreign Government
Schedule of Available-for-sale Securities
Cost or amortized cost	29	28
Gross unrealized gains	0	0
Gross unrealized losses	0	0
Fair value	29	28
Government-Sponsored Enterprises
Schedule of Available-for-sale Securities
Cost or amortized cost	12	137
Gross unrealized gains	0	0
Gross unrealized losses	0	1
Fair value	$ 12	$ 136

Investments (Fair Values And Un

Investments (Fair Values And Unrealized Losses By Investment Category And By The Duration Of The Securities' Continuous Unrealized Loss Position) (Details) - Fixed Maturities - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Investments, Unrealized Loss Position
Less than 12 months fair value	$ 406	$ 340
Less than 12 Months, Unrealized losses	8	4
12 months or more fair value	54	183
12 Months or more, unrealized losses	2	3
Total fair value	460	523
Total Unrealized Losses	10	7
Corporate Securities
Investments, Unrealized Loss Position
Less than 12 months fair value	330	199
Less than 12 Months, Unrealized losses	5	2
12 months or more fair value	46	118
12 Months or more, unrealized losses	2	3
Total fair value	376	317
Total Unrealized Losses	7	5
States, Municipalities and Political Subdivisions
Investments, Unrealized Loss Position
Less than 12 months fair value	31	98
Less than 12 Months, Unrealized losses	2	1
12 months or more fair value	2	10
12 Months or more, unrealized losses	0	0
Total fair value	33	108
Total Unrealized Losses	2	1
Commercial Mortgage Backed Securities
Investments, Unrealized Loss Position
Less than 12 months fair value	23	6
Less than 12 Months, Unrealized losses	1	0
12 months or more fair value	6	0
12 Months or more, unrealized losses	0	0
Total fair value	29	6
Total Unrealized Losses	1	0
United States Government
Investments, Unrealized Loss Position
Less than 12 months fair value	12	0
Less than 12 Months, Unrealized losses	0	0
12 months or more fair value	0	4
12 Months or more, unrealized losses	0	0
Total fair value	12	4
Total Unrealized Losses	0	0
Foreign government
Investments, Unrealized Loss Position
Less than 12 months fair value	10	11
Less than 12 Months, Unrealized losses	0	0
12 months or more fair value	0	0
12 Months or more, unrealized losses	0	0
Total fair value	10	11
Total Unrealized Losses	$ 0	0
Government-Sponsored Enterprises
Investments, Unrealized Loss Position
Less than 12 months fair value		26
Less than 12 Months, Unrealized losses		1
12 months or more fair value		51
12 Months or more, unrealized losses		0
Total fair value		77
Total Unrealized Losses		$ 1

Investments (Contractual Maturi

Investments (Contractual Maturity Dates For Fixed-Maturity And Short-Term Investments) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Amortized cost
Due in one year or less	$ 581
Due after one year through five years	3,450
Due after five years through ten years	3,789
Due after ten years	3,492
Total	11,312	$ 11,108
Fair value
Due in one year or less	589
Due after one year through five years	3,697
Due after five years through ten years	4,178
Due after ten years	3,874
Total	$ 12,338	$ 11,698
% of fair value
Due in one year or less	4.80%
Due after one year through five years	30.00%
Due after five years through ten years	33.90%
Due after ten years	31.30%
Total	100.00%

Investments (Investment Income

Investments (Investment Income Realized Investment Gains And Losses) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Investment income:
Interest	$ 455	$ 446	$ 445
Dividends	220	201	181
Other	8	12	5
Total	683	659	631
Less investment expenses	13	13	12
Total	670	646	619
Gain (Loss) on Sale of Investments	851	1,640	(408)
Investment gains and losses, net:
Other	10	(3)	(12)
Total	865	1,650	(402)
Fixed Maturities
Investment gains and losses, net:
Gross realized gains	16	13	12
Gross realized losses	(3)	(3)	(2)
Write-down of impaired securities	(78)	(9)	(5)
Total	(65)	1	5
Equity Securities
Investment income:
Gain (Loss) on Sale of Investments	79	26	9
Unrealized Gain (Loss) on Investments	841	1,626	(404)
Investment gains and losses, net:
Total	$ 920	$ 1,652	$ (395)

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Principal amount of debt	$ 793	$ 793
Recorded outstanding principal and interest for these life policy loans	95	77
Loss and loss expense reserves	2,915	2,835
Life policy and investment contract reserves	2,915	2,835
Investment contract reserves
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Loss and loss expense reserves	1,562	1,559
Life policy and investment contract reserves	1,562	1,559
Life Policy Loans
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Recorded outstanding principal and interest for these life policy loans	33	32
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Cash and Cash Equivalents, Fair Value Disclosure	$ 900	$ 767

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value Hierarchy For Assets Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	$ 12,338	$ 11,698
Equity securities, at fair value (cost: 2020—$3,927; 2019—$3,581)	8,856	7,752
Separate accounts taxable fixed maturities	952	882
Total	22,148	20,350
Top Hat Savings Plan - Mutual Funds and Common Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Top Hat savings plan mutual funds and common equity (included in Other assets)	51	45
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Total	8,712	7,667
Level 1 | Top Hat Savings Plan - Mutual Funds and Common Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Top Hat savings plan mutual funds and common equity (included in Other assets)	51	45
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Total	13,436	12,683
Level 2 | Top Hat Savings Plan - Mutual Funds and Common Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Top Hat savings plan mutual funds and common equity (included in Other assets)	0	0
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Total	0	0
Level 3 | Top Hat Savings Plan - Mutual Funds and Common Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Top Hat savings plan mutual funds and common equity (included in Other assets)	0	0
Fixed Maturities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	12,338	11,698
Fixed Maturities | Corporate Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	6,895	6,401
Fixed Maturities | States, Municipalities and Political Subdivisions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	4,997	4,728
Fixed Maturities | Commercial Mortgage Backed Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	285	301
Fixed Maturities | United States Government
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	120	104
Fixed Maturities | Foreign Government
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	29	28
Fixed Maturities | Government-Sponsored Enterprises
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	12	136
Fixed Maturities | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	120	104
Fixed Maturities | Level 1 | Corporate Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	0	0
Fixed Maturities | Level 1 | States, Municipalities and Political Subdivisions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	0	0
Fixed Maturities | Level 1 | Commercial Mortgage Backed Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	0	0
Fixed Maturities | Level 1 | United States Government
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	120	104
Fixed Maturities | Level 1 | Foreign Government
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	0	0
Fixed Maturities | Level 1 | Government-Sponsored Enterprises
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	0	0
Fixed Maturities | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	12,218	11,594
Fixed Maturities | Level 2 | Corporate Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	6,895	6,401
Fixed Maturities | Level 2 | States, Municipalities and Political Subdivisions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	4,997	4,728
Fixed Maturities | Level 2 | Commercial Mortgage Backed Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	285	301
Fixed Maturities | Level 2 | United States Government
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	0	0
Fixed Maturities | Level 2 | Foreign Government
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	29	28
Fixed Maturities | Level 2 | Government-Sponsored Enterprises
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	12	136
Fixed Maturities | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	0	0
Fixed Maturities | Level 3 | Corporate Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	0	0
Fixed Maturities | Level 3 | States, Municipalities and Political Subdivisions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	0	0
Fixed Maturities | Level 3 | Commercial Mortgage Backed Securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	0	0
Fixed Maturities | Level 3 | United States Government
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	0	0
Fixed Maturities | Level 3 | Foreign Government
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	0	0
Fixed Maturities | Level 3 | Government-Sponsored Enterprises
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fixed maturities, at fair value (amortized cost: 2020—$11,312; 2019—$11,108)	0	0
Equity Securities | Common Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Equity securities, at fair value (cost: 2020—$3,927; 2019—$3,581)	8,541	7,518
Equity Securities | Nonredeemable Preferred Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Equity securities, at fair value (cost: 2020—$3,927; 2019—$3,581)	315	234
Equity Securities | Level 1 | Common Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Equity securities, at fair value (cost: 2020—$3,927; 2019—$3,581)	8,541	7,518
Equity Securities | Level 1 | Nonredeemable Preferred Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Equity securities, at fair value (cost: 2020—$3,927; 2019—$3,581)	0	0
Equity Securities | Level 2 | Common Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Equity securities, at fair value (cost: 2020—$3,927; 2019—$3,581)	0	0
Equity Securities | Level 2 | Nonredeemable Preferred Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Equity securities, at fair value (cost: 2020—$3,927; 2019—$3,581)	315	234
Equity Securities | Level 3 | Common Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Equity securities, at fair value (cost: 2020—$3,927; 2019—$3,581)	0	0
Equity Securities | Level 3 | Nonredeemable Preferred Equities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Equity securities, at fair value (cost: 2020—$3,927; 2019—$3,581)	0	0
Taxable Fixed Maturities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Separate accounts taxable fixed maturities	903	855
Taxable Fixed Maturities | Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Separate accounts taxable fixed maturities	0	0
Taxable Fixed Maturities | Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Separate accounts taxable fixed maturities	903	855
Taxable Fixed Maturities | Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Separate accounts taxable fixed maturities	$ 0	$ 0

Fair Value Measurements (Fair_2

Fair Value Measurements (Fair Value of Note Payable and Long-Term Debt) (Detail) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of note payable	$ 54	$ 39
Total	1,126	1,091
6.900% Senior Debentures, Due 2028
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	$ 35	$ 34
Interest rate	6.90%	6.90%
6.920% Senior Debentures, Due 2028
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	$ 515	$ 506
Interest rate	6.92%	6.92%
6.125% Senior Notes, Due 2034
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	$ 522	$ 512
Interest rate	6.125%	6.125%
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of note payable	$ 0	$ 0
Total	0	0
Level 1 | 6.900% Senior Debentures, Due 2028
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	0	0
Level 1 | 6.920% Senior Debentures, Due 2028
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	0	0
Level 1 | 6.125% Senior Notes, Due 2034
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	0	0
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of note payable	54	39
Total	1,126	1,091
Level 2 | 6.900% Senior Debentures, Due 2028
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	35	34
Level 2 | 6.920% Senior Debentures, Due 2028
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	515	506
Level 2 | 6.125% Senior Notes, Due 2034
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	522	512
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of note payable	0	0
Total	0	0
Level 3 | 6.900% Senior Debentures, Due 2028
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	0	0
Level 3 | 6.920% Senior Debentures, Due 2028
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	0	0
Level 3 | 6.125% Senior Notes, Due 2034
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of senior debt	$ 0	$ 0

Fair Value Measurements (Fair_3

Fair Value Measurements (Fair Value of Life Policy) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of life policy loans	$ 49	$ 44
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of life policy loans	0	0
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of life policy loans	0	0
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of life policy loans	$ 49	$ 44

Fair Value Measurements (Fair_4

Fair Value Measurements (Fair Value Of Deferred Annuities, Structured Settlements And Other Items) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of deferred annuities and structured settlements	$ 1,063	$ 982
Deferred Annuities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of deferred annuities and structured settlements	836	770
Structured Settlements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of deferred annuities and structured settlements	227	212
Level 1
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of deferred annuities and structured settlements	0	0
Level 1 | Deferred Annuities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of deferred annuities and structured settlements	0	0
Level 1 | Structured Settlements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of deferred annuities and structured settlements	0	0
Level 2
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of deferred annuities and structured settlements	227	212
Level 2 | Deferred Annuities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of deferred annuities and structured settlements	0	0
Level 2 | Structured Settlements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of deferred annuities and structured settlements	227	212
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of deferred annuities and structured settlements	836	770
Level 3 | Deferred Annuities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of deferred annuities and structured settlements	836	770
Level 3 | Structured Settlements
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis
Fair value of deferred annuities and structured settlements	$ 0	$ 0

Property Casualty Loss And Lo_3

Property Casualty Loss And Loss Expenses (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property Casualty Insurance Underwriters
Certain accident, life and health loss reserves	$ 6,677,000,000	$ 6,088,000,000	$ 5,646,000,000	$ 5,219,000,000
Prior year claims and claims adjustments expense, (favorable) and unfavorable	(131,000,000)	(248,000,000)	(167,000,000)
Net loss and loss expense reserves for asbestos and environmental claims	$ 85,000,000	$ 85,000,000
Percentage of reserves for asbestos and environmental claims	2.00%	2.00%
Maximum
Property Casualty Insurance Underwriters
Reinsurance retention	$ 500,000
Life and Health Loss Reserves
Property Casualty Insurance Underwriters
Certain accident, life and health loss reserves	69,000,000	$ 59,000,000	61,000,000
Commercial Insurance
Property Casualty Insurance Underwriters
Prior year claims and claims adjustments expense, (favorable) and unfavorable	(95,000,000)	(192,000,000)	(157,000,000)
Commercial Insurance | Commercial Casualty Line
Property Casualty Insurance Underwriters
Certain accident, life and health loss reserves	2,282,000,000
Prior year claims and claims adjustments expense, (favorable) and unfavorable	(54,000,000)	(78,000,000)	(47,000,000)
Commercial Insurance | Workers' Compensation Line
Property Casualty Insurance Underwriters
Certain accident, life and health loss reserves	1,002,000,000
Prior year claims and claims adjustments expense, (favorable) and unfavorable	(39,000,000)	(77,000,000)	(58,000,000)
Commercial Insurance | Commercial Property Line
Property Casualty Insurance Underwriters
Certain accident, life and health loss reserves	514,000,000
Prior year claims and claims adjustments expense, (favorable) and unfavorable	(16,000,000)	(25,000,000)	(47,000,000)
Commercial Insurance | Commercial Auto Line
Property Casualty Insurance Underwriters
Certain accident, life and health loss reserves	685,000,000
Prior year claims and claims adjustments expense, (favorable) and unfavorable	17,000,000	(6,000,000)
Personal Insurance
Property Casualty Insurance Underwriters
Prior year claims and claims adjustments expense, (favorable) and unfavorable	(18,000,000)	(27,000,000)	13,000,000
Personal Insurance | Personal Auto
Property Casualty Insurance Underwriters
Certain accident, life and health loss reserves	292,000,000
Prior year claims and claims adjustments expense, (favorable) and unfavorable	(15,000,000)	(26,000,000)
Personal Insurance | Homeowner
Property Casualty Insurance Underwriters
Prior year claims and claims adjustments expense, (favorable) and unfavorable	(5,000,000)	11,000,000
Excess and Surplus Lines Insurance
Property Casualty Insurance Underwriters
Certain accident, life and health loss reserves	423,000,000
Prior year claims and claims adjustments expense, (favorable) and unfavorable	7,000,000	(11,000,000)	(24,000,000)
Reinsurance assumed and other non segment
Property Casualty Insurance Underwriters
Prior year claims and claims adjustments expense, (favorable) and unfavorable	$ (25,000,000)	$ (18,000,000)	$ 1,000,000

Consolidated Property Casualty

Consolidated Property Casualty Loss And Loss Expense Reserves (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Feb. 28, 2019
Business Acquisition
Gross loss and loss expense reserves, January 1	$ 6,088	$ 5,646	$ 5,219
Less reinsurance recoverable	342	238	187
Net loss and loss expense reserves, January 1	5,746	5,408	5,032
Net incurred loss and loss expenses related to:
Current accident year	3,968	3,600	3,390
Prior accident years	(131)	(248)	(167)
Total incurred	3,837	3,352	3,223
Net paid loss and loss expenses related to:
Current accident year	1,493	1,462	1,391
Prior accident years	1,690	1,798	1,456
Total paid	3,183	3,260	2,847
Net loss and loss expense reserves, December 31	6,400	5,746	5,408
Plus reinsurance recoverable	277	342	238
Gross loss and loss expense reserves, December 31	$ 6,677	$ 6,088	$ 5,646
Cincinnati Global
Business Acquisition
Net loss and loss expense reserves related to acquisition of Cincinnati Global at February 28, 2019				$ 246

Reconciliation of Incurred Loss

Reconciliation of Incurred Losses and ALAE (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Liability for Claims and Claims Adjustment Expense
Cumulative incurred losses and ALAE as reported within the triangles, net of reinsurance	$ 3,158
Total liabilities for loss and ALAE, net of reinsurance	6,394
Reinsurance recoverable on unpaid losses	277	$ 342	$ 238	$ 187
Unallocated loss adjustment expense reserves	283
Total liabilities for gross loss and loss expense reserves	6,677	$ 6,088	$ 5,646	$ 5,219
Other Short-duration Insurance Product Line
Liability for Claims and Claims Adjustment Expense
Total liabilities for loss and ALAE, net of reinsurance	959
Commercial Insurance | Commercial Casualty Line
Liability for Claims and Claims Adjustment Expense
Cumulative incurred losses and ALAE as reported within the triangles, net of reinsurance	5,179
Cumulative paid losses and ALAE as reported within the triangles, net of reinsurance	3,012
Liabilities for loss and ALAE for accident years not presented in the triangles, net of reinsurance	91
Total liabilities for loss and ALAE, net of reinsurance	2,258
Reinsurance recoverable on unpaid losses	24
Total liabilities for gross loss and loss expense reserves	2,282
Commercial Insurance | Workers' Compensation Line
Liability for Claims and Claims Adjustment Expense
Cumulative incurred losses and ALAE as reported within the triangles, net of reinsurance	1,990
Cumulative paid losses and ALAE as reported within the triangles, net of reinsurance	1,357
Liabilities for loss and ALAE for accident years not presented in the triangles, net of reinsurance	308
Total liabilities for loss and ALAE, net of reinsurance	941
Reinsurance recoverable on unpaid losses	61
Total liabilities for gross loss and loss expense reserves	1,002
Commercial Insurance | Commercial Auto Line
Liability for Claims and Claims Adjustment Expense
Cumulative incurred losses and ALAE as reported within the triangles, net of reinsurance	2,235
Cumulative paid losses and ALAE as reported within the triangles, net of reinsurance	1,581
Liabilities for loss and ALAE for accident years not presented in the triangles, net of reinsurance	26
Total liabilities for loss and ALAE, net of reinsurance	680
Reinsurance recoverable on unpaid losses	5
Total liabilities for gross loss and loss expense reserves	685
Commercial Insurance | Commercial Property Line
Liability for Claims and Claims Adjustment Expense
Cumulative incurred losses and ALAE as reported within the triangles, net of reinsurance	3,158
Cumulative paid losses and ALAE as reported within the triangles, net of reinsurance	2,725
Liabilities for loss and ALAE for accident years not presented in the triangles, net of reinsurance	15
Total liabilities for loss and ALAE, net of reinsurance	448
Reinsurance recoverable on unpaid losses	66
Total liabilities for gross loss and loss expense reserves	514
Personal Insurance | Personal Auto
Liability for Claims and Claims Adjustment Expense
Cumulative incurred losses and ALAE as reported within the triangles, net of reinsurance	1,860
Cumulative paid losses and ALAE as reported within the triangles, net of reinsurance	1,610
Liabilities for loss and ALAE for accident years not presented in the triangles, net of reinsurance	10
Total liabilities for loss and ALAE, net of reinsurance	260
Reinsurance recoverable on unpaid losses	32
Total liabilities for gross loss and loss expense reserves	292
Personal Insurance | Home Owner Line
Liability for Claims and Claims Adjustment Expense
Cumulative incurred losses and ALAE as reported within the triangles, net of reinsurance	1,996
Cumulative paid losses and ALAE as reported within the triangles, net of reinsurance	1,781
Liabilities for loss and ALAE for accident years not presented in the triangles, net of reinsurance	4
Total liabilities for loss and ALAE, net of reinsurance	219
Reinsurance recoverable on unpaid losses	18
Total liabilities for gross loss and loss expense reserves	237
Excess and Surplus Lines Insurance
Liability for Claims and Claims Adjustment Expense
Cumulative incurred losses and ALAE as reported within the triangles, net of reinsurance	836
Cumulative paid losses and ALAE as reported within the triangles, net of reinsurance	430
Liabilities for loss and ALAE for accident years not presented in the triangles, net of reinsurance	1
Total liabilities for loss and ALAE, net of reinsurance	407
Reinsurance recoverable on unpaid losses	16
Total liabilities for gross loss and loss expense reserves	$ 423

Claims Development - Commercial

Claims Development - Commercial Casualty (Details) reported_claim in Thousands, $ in Millions	Dec. 31, 2020USD ($)reported_claim	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Dec. 31, 2012USD ($)	Dec. 31, 2011USD ($)
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	$ 3,158
Liabilities for loss and ALAE, net of reinsurance	6,394
Commercial Casualty Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	5,179
Cumulative paid losses and ALAE, net of reinsurance	3,012
All outstanding liabilities before, net of reinsurance	91
Liabilities for loss and ALAE, net of reinsurance	2,258
2011 | Commercial Casualty Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	361	$ 368	$ 365	$ 366	$ 380	$ 375	$ 377	$ 377	$ 404	$ 466
Total of incurred but not reported liabilities plus expected development on reported losses	$ 0
Cumulative number of reported claims | reported_claim	19
Cumulative paid losses and ALAE, net of reinsurance	$ 342	337	325	315	298	266	227	149	93	$ 27
2012 | Commercial Casualty Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	397	397	399	404	394	394	417	414	466
Total of incurred but not reported liabilities plus expected development on reported losses	$ 11
Cumulative number of reported claims | reported_claim	18
Cumulative paid losses and ALAE, net of reinsurance	$ 374	364	346	330	288	232	170	88	$ 27
2013 | Commercial Casualty Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	386	391	407	413	416	431	443	448
Total of incurred but not reported liabilities plus expected development on reported losses	$ 22
Cumulative number of reported claims | reported_claim	20
Cumulative paid losses and ALAE, net of reinsurance	$ 348	337	312	286	232	159	90	$ 35
2014 | Commercial Casualty Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	469	465	479	476	479	496	503
Total of incurred but not reported liabilities plus expected development on reported losses	$ 27
Cumulative number of reported claims | reported_claim	21
Cumulative paid losses and ALAE, net of reinsurance	$ 409	390	338	287	172	97	$ 34
2015 | Commercial Casualty Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	502	508	516	529	526	533
Total of incurred but not reported liabilities plus expected development on reported losses	$ 54
Cumulative number of reported claims | reported_claim	21
Cumulative paid losses and ALAE, net of reinsurance	$ 404	362	287	200	108	$ 38
2016 | Commercial Casualty Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	554	555	557	574	563
Total of incurred but not reported liabilities plus expected development on reported losses	$ 89
Cumulative number of reported claims | reported_claim	21
Cumulative paid losses and ALAE, net of reinsurance	$ 395	331	228	126	$ 46
2017 | Commercial Casualty Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	571	577	597	610
Total of incurred but not reported liabilities plus expected development on reported losses	$ 124
Cumulative number of reported claims | reported_claim	21
Cumulative paid losses and ALAE, net of reinsurance	$ 320	234	122	$ 48
2018 | Commercial Casualty Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	622	641	650
Total of incurred but not reported liabilities plus expected development on reported losses	$ 181
Cumulative number of reported claims | reported_claim	22
Cumulative paid losses and ALAE, net of reinsurance	$ 253	148	$ 44
2019 | Commercial Casualty Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	643	672
Total of incurred but not reported liabilities plus expected development on reported losses	$ 293
Cumulative number of reported claims | reported_claim	19
Cumulative paid losses and ALAE, net of reinsurance	$ 134	$ 39
2020 | Commercial Casualty Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	674
Total of incurred but not reported liabilities plus expected development on reported losses	$ 472
Cumulative number of reported claims | reported_claim	11
Cumulative paid losses and ALAE, net of reinsurance	$ 33

Claims Development - Workers Co

Claims Development - Workers Compensation (Details) reported_claim in Thousands, $ in Millions	Dec. 31, 2020USD ($)reported_claim	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Dec. 31, 2012USD ($)	Dec. 31, 2011USD ($)
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	$ 3,158
Liabilities for loss and ALAE, net of reinsurance	6,394
Workers' Compensation Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	1,990
Cumulative paid losses and ALAE, net of reinsurance	1,357
All outstanding liabilities before, net of reinsurance	308
Liabilities for loss and ALAE, net of reinsurance	941
2011 | Workers' Compensation Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	228	$ 228	$ 229	$ 231	$ 236	$ 239	$ 242	$ 246	$ 251	$ 284
Total of incurred but not reported liabilities plus expected development on reported losses	$ 17
Cumulative number of reported claims | reported_claim	24
Cumulative paid losses and ALAE, net of reinsurance	$ 198	197	195	192	190	186	177	161	131	$ 65
2012 | Workers' Compensation Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	207	208	209	211	213	220	234	245	265
Total of incurred but not reported liabilities plus expected development on reported losses	$ 19
Cumulative number of reported claims | reported_claim	21
Cumulative paid losses and ALAE, net of reinsurance	$ 182	180	178	175	171	162	147	121	$ 62
2013 | Workers' Compensation Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	201	202	205	208	212	221	246	264
Total of incurred but not reported liabilities plus expected development on reported losses	$ 12
Cumulative number of reported claims | reported_claim	20
Cumulative paid losses and ALAE, net of reinsurance	$ 174	170	168	164	157	144	119	$ 61
2014 | Workers' Compensation Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	197	198	201	203	214	233	261
Total of incurred but not reported liabilities plus expected development on reported losses	$ 13
Cumulative number of reported claims | reported_claim	19
Cumulative paid losses and ALAE, net of reinsurance	$ 165	162	157	148	134	110	$ 56
2015 | Workers' Compensation Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	173	179	195	208	220	246
Total of incurred but not reported liabilities plus expected development on reported losses	$ 26
Cumulative number of reported claims | reported_claim	17
Cumulative paid losses and ALAE, net of reinsurance	$ 137	134	129	115	93	$ 47
2016 | Workers' Compensation Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	183	188	206	218	230
Total of incurred but not reported liabilities plus expected development on reported losses	$ 27
Cumulative number of reported claims | reported_claim	16
Cumulative paid losses and ALAE, net of reinsurance	$ 141	131	119	97	$ 46
2017 | Workers' Compensation Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	183	190	208	218
Total of incurred but not reported liabilities plus expected development on reported losses	$ 46
Cumulative number of reported claims | reported_claim	15
Cumulative paid losses and ALAE, net of reinsurance	$ 114	106	88	$ 45
2018 | Workers' Compensation Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	199	207	222
Total of incurred but not reported liabilities plus expected development on reported losses	$ 52
Cumulative number of reported claims | reported_claim	15
Cumulative paid losses and ALAE, net of reinsurance	$ 115	95	$ 48
2019 | Workers' Compensation Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	215	224
Total of incurred but not reported liabilities plus expected development on reported losses	$ 65
Cumulative number of reported claims | reported_claim	14
Cumulative paid losses and ALAE, net of reinsurance	$ 94	$ 49
2020 | Workers' Compensation Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	204
Total of incurred but not reported liabilities plus expected development on reported losses	$ 100
Cumulative number of reported claims | reported_claim	10
Cumulative paid losses and ALAE, net of reinsurance	$ 37

Claims Development - Commerci_2

Claims Development - Commercial Auto (Details) reported_claim in Thousands, $ in Millions	Dec. 31, 2020USD ($)reported_claim	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	$ 3,158
Liabilities for loss and ALAE, net of reinsurance	6,394
Commercial Auto Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	2,235
Cumulative paid losses and ALAE, net of reinsurance	1,581
All outstanding liabilities before, net of reinsurance	26
Liabilities for loss and ALAE, net of reinsurance	680
2016 | Commercial Auto Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	474	$ 463	$ 450	$ 430	$ 417
Total of incurred but not reported liabilities plus expected development on reported losses	$ 5
Cumulative number of reported claims | reported_claim	53
Cumulative paid losses and ALAE, net of reinsurance	$ 441	408	350	273	$ 184
2017 | Commercial Auto Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	444	443	441	451
Total of incurred but not reported liabilities plus expected development on reported losses	$ 13
Cumulative number of reported claims | reported_claim	51
Cumulative paid losses and ALAE, net of reinsurance	$ 381	334	266	$ 187
2018 | Commercial Auto Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	442	442	453
Total of incurred but not reported liabilities plus expected development on reported losses	$ 36
Cumulative number of reported claims | reported_claim	49
Cumulative paid losses and ALAE, net of reinsurance	$ 337	266	$ 184
2019 | Commercial Auto Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	451	452
Total of incurred but not reported liabilities plus expected development on reported losses	$ 73
Cumulative number of reported claims | reported_claim	46
Cumulative paid losses and ALAE, net of reinsurance	$ 268	$ 183
2020 | Commercial Auto Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	424
Total of incurred but not reported liabilities plus expected development on reported losses	$ 164
Cumulative number of reported claims | reported_claim	33
Cumulative paid losses and ALAE, net of reinsurance	$ 154

Claims Development - Commerci_3

Claims Development - Commercial Property (Details) reported_claim in Thousands, $ in Millions	Dec. 31, 2020USD ($)reported_claim	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	$ 3,158
Liabilities for loss and ALAE, net of reinsurance	6,394
Commercial Property Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	3,158
Cumulative paid losses and ALAE, net of reinsurance	2,725
All outstanding liabilities before, net of reinsurance	15
Liabilities for loss and ALAE, net of reinsurance	448
2016 | Commercial Property Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	542	$ 545	$ 541	$ 551	$ 590
Total of incurred but not reported liabilities plus expected development on reported losses	$ 2
Cumulative number of reported claims | reported_claim	17
Cumulative paid losses and ALAE, net of reinsurance	$ 539	539	528	504	$ 358
2017 | Commercial Property Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	565	556	560	587
Total of incurred but not reported liabilities plus expected development on reported losses	$ 3
Cumulative number of reported claims | reported_claim	18
Cumulative paid losses and ALAE, net of reinsurance	$ 560	547	522	$ 395
2018 | Commercial Property Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	590	603	630
Total of incurred but not reported liabilities plus expected development on reported losses	$ 7
Cumulative number of reported claims | reported_claim	18
Cumulative paid losses and ALAE, net of reinsurance	$ 576	559	$ 386
2019 | Commercial Property Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	606	621
Total of incurred but not reported liabilities plus expected development on reported losses	$ 6
Cumulative number of reported claims | reported_claim	17
Cumulative paid losses and ALAE, net of reinsurance	$ 561	$ 413
2020 | Commercial Property Line | Commercial Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	855
Total of incurred but not reported liabilities plus expected development on reported losses	$ 141
Cumulative number of reported claims | reported_claim	22
Cumulative paid losses and ALAE, net of reinsurance	$ 489

Claims Development - Personal A

Claims Development - Personal Auto (Details) reported_claim in Thousands, $ in Millions	Dec. 31, 2020USD ($)reported_claim	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	$ 3,158
Liabilities for loss and ALAE, net of reinsurance	6,394
Personal Auto | Personal Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	1,860
Cumulative paid losses and ALAE, net of reinsurance	1,610
All outstanding liabilities before, net of reinsurance	10
Liabilities for loss and ALAE, net of reinsurance	260
2016 | Personal Auto | Personal Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	384	$ 384	$ 386	$ 384	$ 383
Total of incurred but not reported liabilities plus expected development on reported losses	$ 1
Cumulative number of reported claims | reported_claim	110
Cumulative paid losses and ALAE, net of reinsurance	$ 378	370	351	316	$ 243
2017 | Personal Auto | Personal Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	393	391	394	412
Total of incurred but not reported liabilities plus expected development on reported losses	$ 1
Cumulative number of reported claims | reported_claim	109
Cumulative paid losses and ALAE, net of reinsurance	$ 374	358	324	$ 256
2018 | Personal Auto | Personal Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	395	398	424
Total of incurred but not reported liabilities plus expected development on reported losses	$ 1
Cumulative number of reported claims | reported_claim	111
Cumulative paid losses and ALAE, net of reinsurance	$ 358	327	$ 262
2019 | Personal Auto | Personal Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	383	399
Total of incurred but not reported liabilities plus expected development on reported losses	$ 14
Cumulative number of reported claims | reported_claim	102
Cumulative paid losses and ALAE, net of reinsurance	$ 314	$ 250
2020 | Personal Auto | Personal Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	305
Total of incurred but not reported liabilities plus expected development on reported losses	$ 62
Cumulative number of reported claims | reported_claim	67
Cumulative paid losses and ALAE, net of reinsurance	$ 186

Claims Development - Homeowner

Claims Development - Homeowner (Details) reported_claim in Thousands, $ in Millions	Dec. 31, 2020USD ($)reported_claim	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	$ 3,158
Liabilities for loss and ALAE, net of reinsurance	6,394
Home Owner Line | Personal Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	1,996
Cumulative paid losses and ALAE, net of reinsurance	1,781
All outstanding liabilities before, net of reinsurance	4
Liabilities for loss and ALAE, net of reinsurance	219
2016 | Home Owner Line | Personal Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	304	$ 302	$ 303	$ 304	$ 315
Total of incurred but not reported liabilities plus expected development on reported losses	$ 0
Cumulative number of reported claims | reported_claim	23
Cumulative paid losses and ALAE, net of reinsurance	$ 302	299	295	283	$ 208
2017 | Home Owner Line | Personal Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	387	385	383	356
Total of incurred but not reported liabilities plus expected development on reported losses	$ 0
Cumulative number of reported claims | reported_claim	26
Cumulative paid losses and ALAE, net of reinsurance	$ 384	378	356	$ 277
2018 | Home Owner Line | Personal Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	387	386	370
Total of incurred but not reported liabilities plus expected development on reported losses	$ 5
Cumulative number of reported claims | reported_claim	24
Cumulative paid losses and ALAE, net of reinsurance	$ 378	368	$ 268
2019 | Home Owner Line | Personal Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	421	432
Total of incurred but not reported liabilities plus expected development on reported losses	$ 10
Cumulative number of reported claims | reported_claim	22
Cumulative paid losses and ALAE, net of reinsurance	$ 391	$ 303
2020 | Home Owner Line | Personal Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	497
Total of incurred but not reported liabilities plus expected development on reported losses	$ 54
Cumulative number of reported claims | reported_claim	21
Cumulative paid losses and ALAE, net of reinsurance	$ 326

Claims Development - Excess and

Claims Development - Excess and Surplus Lines (Details) reported_claim in Thousands, $ in Millions	Dec. 31, 2020USD ($)reported_claim	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)	Dec. 31, 2012USD ($)	Dec. 31, 2011USD ($)
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	$ 3,158
Liabilities for loss and ALAE, net of reinsurance	6,394
Excess and Surplus Lines Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	836
Cumulative paid losses and ALAE, net of reinsurance	430
All outstanding liabilities before, net of reinsurance	1
Liabilities for loss and ALAE, net of reinsurance	407
2011 | Excess and Surplus Lines Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	34	$ 34	$ 34	$ 35	$ 35	$ 36	$ 38	$ 44	$ 47	$ 48
Total of incurred but not reported liabilities plus expected development on reported losses	$ 0
Cumulative number of reported claims | reported_claim	1
Cumulative paid losses and ALAE, net of reinsurance	$ 33	33	33	34	32	30	27	23	14	$ 8
2012 | Excess and Surplus Lines Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	35	36	35	36	37	40	49	56	67
Total of incurred but not reported liabilities plus expected development on reported losses	$ 0
Cumulative number of reported claims | reported_claim	1
Cumulative paid losses and ALAE, net of reinsurance	$ 34	33	32	31	29	25	19	15	$ 9
2013 | Excess and Surplus Lines Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	41	41	41	42	45	54	64	74
Total of incurred but not reported liabilities plus expected development on reported losses	$ 2
Cumulative number of reported claims | reported_claim	2
Cumulative paid losses and ALAE, net of reinsurance	$ 39	37	34	32	27	20	12	$ 7
2014 | Excess and Surplus Lines Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	59	59	60	64	75	82	95
Total of incurred but not reported liabilities plus expected development on reported losses	$ 5
Cumulative number of reported claims | reported_claim	2
Cumulative paid losses and ALAE, net of reinsurance	$ 51	48	43	37	27	17	$ 9
2015 | Excess and Surplus Lines Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	66	65	67	73	81	96
Total of incurred but not reported liabilities plus expected development on reported losses	$ 6
Cumulative number of reported claims | reported_claim	2
Cumulative paid losses and ALAE, net of reinsurance	$ 54	51	41	29	19	$ 8
2016 | Excess and Surplus Lines Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	90	82	84	87	93
Total of incurred but not reported liabilities plus expected development on reported losses	$ 13
Cumulative number of reported claims | reported_claim	3
Cumulative paid losses and ALAE, net of reinsurance	$ 62	51	39	21	$ 10
2017 | Excess and Surplus Lines Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	94	95	95	104
Total of incurred but not reported liabilities plus expected development on reported losses	$ 15
Cumulative number of reported claims | reported_claim	3
Cumulative paid losses and ALAE, net of reinsurance	$ 57	41	23	$ 11
2018 | Excess and Surplus Lines Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	110	109	116
Total of incurred but not reported liabilities plus expected development on reported losses	$ 29
Cumulative number of reported claims | reported_claim	3
Cumulative paid losses and ALAE, net of reinsurance	$ 50	26	$ 11
2019 | Excess and Surplus Lines Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	135	137
Total of incurred but not reported liabilities plus expected development on reported losses	$ 50
Cumulative number of reported claims | reported_claim	3
Cumulative paid losses and ALAE, net of reinsurance	$ 34	$ 13
2020 | Excess and Surplus Lines Insurance
Claims Development
Incurred losses and ALAE, net of reinsurance for the years ended December 31,	172
Total of incurred but not reported liabilities plus expected development on reported losses	$ 105
Cumulative number of reported claims | reported_claim	2
Cumulative paid losses and ALAE, net of reinsurance	$ 16

Average Annual Payout (Details)

Average Annual Payout (Details)	Dec. 31, 2020
Commercial Insurance | Commercial Casualty Line
Short-duration Insurance Contracts, Historical Claims Duration
1	7.30%
2	14.90%
3	17.90%
4	18.80%
5	12.70%
6	9.10%
7	4.80%
8	3.50%
9	3.00%
10	1.70%
Commercial Insurance | Workers' Compensation Line
Short-duration Insurance Contracts, Historical Claims Duration
1	25.90%
2	26.30%
3	11.90%
4	6.70%
5	4.10%
6	2.00%
7	1.40%
8	1.20%
9	1.10%
10	0.50%
Commercial Insurance | Commercial Auto Line
Short-duration Insurance Contracts, Historical Claims Duration
1	39.90%
2	18.60%
3	15.80%
4	11.50%
5	7.00%
Commercial Insurance | Commercial Property Line
Short-duration Insurance Contracts, Historical Claims Duration
1	65.30%
2	25.80%
3	3.90%
4	2.10%
5	0.10%
Personal Insurance | Personal Auto
Short-duration Insurance Contracts, Historical Claims Duration
1	64.20%
2	17.30%
3	8.60%
4	4.60%
5	2.00%
Personal Insurance | Home Owner Line
Short-duration Insurance Contracts, Historical Claims Duration
1	69.30%
2	23.00%
3	4.10%
4	1.40%
5	0.80%
Excess and Surplus Lines Insurance
Short-duration Insurance Contracts, Historical Claims Duration
1	14.60%
2	14.40%
3	19.20%
4	15.40%
5	11.70%
6	6.90%
7	3.90%
8	2.20%
9	1.00%
10	0.20%

Life Policy And Investment Co_3

Life Policy And Investment Contract Reservess (Reserve In Addition To The Account Balance Based On Expected No-Lapse Guarantee Benefits And Expected Policy Assessments) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Liability for Future Policy Benefit, by Product Segment
Life policy and investment contract reserves	$ 2,915	$ 2,835
Life Policy Reserves
Liability for Future Policy Benefit, by Product Segment
Life policy and investment contract reserves	1,353	1,276
Life Policy Reserves | Ordinary/Traditional Life
Liability for Future Policy Benefit, by Product Segment
Life policy and investment contract reserves	1,301	1,226
Life Policy Reserves | Other Life Policy Reserves
Liability for Future Policy Benefit, by Product Segment
Life policy and investment contract reserves	52	50
Investment contract reserves
Liability for Future Policy Benefit, by Product Segment
Life policy and investment contract reserves	1,562	1,559
Investment contract reserves | Deferred Annuity
Liability for Future Policy Benefit, by Product Segment
Life policy and investment contract reserves	761	760
Investment contract reserves | Universal Life
Liability for Future Policy Benefit, by Product Segment
Life policy and investment contract reserves	647	640
Investment contract reserves | Structured Settlement Annuity
Liability for Future Policy Benefit, by Product Segment
Life policy and investment contract reserves	145	151
Investment contract reserves | Other Investment Contract Reserves
Liability for Future Policy Benefit, by Product Segment
Life policy and investment contract reserves	$ 9	$ 8

Deferred Policy Acquisition C_3

Deferred Policy Acquisition Costs (Deferred Policy Acquisition Costs And Asset Reconciliation Including The Amortized Deferred Policy Acquisition Costs) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Deferred Costs [Roll Forward]
Deferred policy acquisition costs asset at January 1	$ 774	$ 738	$ 670
Capitalized deferred policy acquisition costs	1,145	1,095	993
Amortized deferred policy acquisition costs	(1,106)	(1,034)	(946)
Shadow deferred policy acquisition costs	(8)	(25)	21
Deferred policy acquisition costs asset at December 31	805	774	738
Life Insurance Segment
Deferred Costs [Roll Forward]
Deferred policy acquisition costs asset at January 1	262	274	232
Capitalized deferred policy acquisition costs	58	61	60
Amortized deferred policy acquisition costs	(49)	(48)	(39)
Shadow deferred policy acquisition costs	(8)	(25)	21
Deferred policy acquisition costs asset at December 31	263	262	274
Consolidated Property And Casualty Insurance Entity
Deferred Costs [Roll Forward]
Deferred policy acquisition costs asset at January 1	512	464	438
Capitalized deferred policy acquisition costs	1,087	1,034	933
Amortized deferred policy acquisition costs	(1,057)	(986)	(907)
Deferred policy acquisition costs asset at December 31	$ 542	$ 512	$ 464

Note Payable (Narrative) (Detai

Note Payable (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Debt Disclosure
Number of lines of credit	1
Aggregate borrowing capacity	$ 300
Accordian feature available amount	300
Note payable	$ 54	$ 39
Ratio of debt-to-total capital maximum	0.35
Minimum
Debt Disclosure
Line of credit, interest rate	1.03%	2.59%
Maximum
Debt Disclosure
Line of credit, interest rate	4.25%	3.41%

Long-Term Debt And Lease Obli_3

Long-Term Debt And Lease Obligation (Book Value And Principal Amounts Of Long-Term Debt (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument
Book value	$ 788	$ 788
Principal amount	$ 793	$ 793
6.900% Senior Debentures, Due 2028
Debt Instrument
Interest rate	6.90%	6.90%
Book value	$ 27	$ 27
Principal amount	$ 28	$ 28
6.920% Senior Debentures, Due 2028
Debt Instrument
Interest rate	6.92%	6.92%
Book value	$ 391	$ 391
Principal amount	$ 391	$ 391
6.125% Senior Notes, Due 2034
Debt Instrument
Interest rate	6.125%	6.125%
Book value	$ 370	$ 370
Principal amount	$ 374	$ 374

Long-Term Debt And Lease Obli_4

Long-Term Debt And Lease Obligation (Lease Payments Over Next Five Years) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)
Long-term Debt and Lease Obligation [Abstract]
Finance Lease 2021	$ 15
Finance Lease 2022	12
Finance Lease 2023	10
Finance Lease 2024	6
Finance Lease 2025	4
Finance Lease 2026 and thereafter	2
Operating Leases 2021	2
Operating Leases 2022	2
Operating Leases 2023	2
Operating Leases 2024	2
Operating Leases 2025	1
Operating Leases 2026 and thereafter	2
Total Finance and Operating Lease 2021	17
Total Finance and Operating Lease 2022	14
Total Finance and Operating Lease 2023	12
Total Finance and Operating Lease 2024	8
Total Finance and Operating Lease 2025	5
Total Finance and Operating Lease 2026 and thereafter	$ 4

Long-Term Debt And Lease Obli_5

Long-Term Debt And Lease Obligation Long-term Debt and Lease Obligation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Long-term Debt and Lease Obligation [Abstract]
Finance Lease, Right-of-Use Asset, Amortization	$ 15	$ 9
Operating Lease, Expense	4	4
Total Finance and Operating Lease Cost	19	13
Finance Lease, Principal Payments	$ 15	$ 15
Finance Lease, Weighted Average Discount Rate, Percent	2.62%	2.96%
Finance Lease, Weighted Average Remaining Lease Term	3 years 8 months 1 day	3 years 7 months 24 days
Operating Lease, Payments	$ 8	$ 8
Operating Lease, Weighted Average Discount Rate, Percent	3.65%	3.69%
Operating Lease, Weighted Average Remaining Lease Term	4 years 10 months 2 days	4 years 8 months 15 days

Long-Term Debt And Lease Obli_6

Long-Term Debt And Lease Obligation Long-Term Debt and Lease Obligation Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Lessee, Lease, Description [Line Items]
Lessee, Operating Lease, Term of Contract	5 years
Total lease liability	$ 57	$ 57
Interest Costs Incurred	$ 3
Maximum
Lessee, Lease, Description [Line Items]
Lessee, Finance Lease, Term of Contract	6 years
Minimum
Lessee, Lease, Description [Line Items]
Lessee, Finance Lease, Term of Contract	3 years

Shareholders' Equity And Divi_3

Shareholders' Equity And Dividend Restrictions (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Declared cash dividends, per share	$ 2.40	$ 2.24	$ 2.12
Dividend payment without prior regulatory approval, maximum percent of policyholder surplus	10.00%
Dividend payment without prior regulatory approval, percent of statutory net income for the prior calendar year	100.00%
Dividends might be paid during next year	$ 583
The Cincinnati Insurance Company
Cash Dividends Paid to Parent	550	$ 625	$ 500
Cincinnati Global
Cash Dividends Paid to Parent	$ 0	$ 0

Shareholders' Equity And Divi_4

Shareholders' Equity And Dividend Restrictions (Change In AOCI Includes Changes In Unrealized Gains And Losses On Investments And Pension Obligations) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2020	Jan. 01, 2019	Jan. 01, 2018	Dec. 31, 2017
Accumulated Other Comprehensive Income, Before Tax
Pension obligations OCI	$ (32)	$ 7	$ (4)
Accumulated Other Comprehensive Income, Net of Tax
AOCI, balance at the beginning of the period	448
AOCI, balance at the end of the period	769	448
Accumulated Net Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income, Before Tax
AOCI, balance at the beginning of the period	590	46	3,540
Cumulative effect of new accounting principle, before tax		0	0				$ (3,155)
Adjusted AOCI, beginning of period		590	46				385
OCI before investment gains and losses, net, recognized in net income	371	545	(334)
Investment gains and losses, net, recognized in net income	65	(1)	(5)
OCI	436	544	(339)
AOCI, balance at the end of the period	1,026	590	46
Accumulated Other Comprehensive Income, Income Tax
AOCI, balance at the beginning of the period	123	9	733
Cumulative effect of new account principle, tax		0	0				(652)
Adjusted AOCI, beginning of period		123	9				81
OCI before investment gains and losses, net, recognized in net income	78	115	(71)
Investment gains and losses, net, recognized in net income	14	(1)	(1)
OCI	92	114	(72)
AOCI, balance at the end of the period	215	123	9
Accumulated Other Comprehensive Income, Net of Tax
AOCI, balance at the beginning of the period	467	37	2,807
Unrealized gains reclassified to retained earnings for ASU 2016-01, after tax		0	0				(2,503)
Adjusted AOCI, beginning of period		467	37				304
OCI before investment gains and losses, net, recognized in net income	293	430	(263)
Investment gains and losses, net, recognized in net income	51	0	(4)
OCI	344	430	(267)
AOCI, balance at the end of the period	811	467	37
Accumulated Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income, Before Tax
AOCI, balance at the beginning of the period	(9)	(16)	(12)
OCI before investment gains and losses, net, recognized in net income	(35)	6	(5)
Investment gains and losses, net, recognized in net income	3	1	1
OCI	(32)	7	(4)
AOCI, balance at the end of the period	(41)	(9)	(16)
Accumulated Other Comprehensive Income, Income Tax
AOCI, balance at the beginning of the period	0	(2)	(1)
OCI before investment gains and losses, net, recognized in net income	(7)	2	(1)
Investment gains and losses, net, recognized in net income	0	0	0
OCI	(7)	2	(1)
AOCI, balance at the end of the period	(7)	0	(2)
Accumulated Other Comprehensive Income, Net of Tax
AOCI, balance at the beginning of the period	(9)	(14)	(11)
OCI before investment gains and losses, net, recognized in net income	(28)	4	(4)
Investment gains and losses, net, recognized in net income	3	1	1
OCI	(25)	5	(3)
AOCI, balance at the end of the period	(34)	(9)	(14)
Accumulated Net Unrealized Gain (Loss) on Deferred Costs, Reserves And Other
Accumulated Other Comprehensive Income, Before Tax
AOCI, balance at the beginning of the period	(13)	(1)	(10)
OCI before investment gains and losses, net, recognized in net income	3	(15)	(3)
Investment gains and losses, net, recognized in net income	0	3	12
OCI	3	(12)	9
AOCI, balance at the end of the period	(10)	(13)	(1)
Accumulated Other Comprehensive Income, Income Tax
AOCI, balance at the beginning of the period	(3)	0	(2)
OCI before investment gains and losses, net, recognized in net income	1	(3)	(1)
Investment gains and losses, net, recognized in net income	0	0	3
OCI	1	(3)	2
AOCI, balance at the end of the period	(2)	(3)	0
Accumulated Other Comprehensive Income, Net of Tax
AOCI, balance at the beginning of the period	(10)	(1)	(8)
OCI before investment gains and losses, net, recognized in net income	2	(12)	(2)
Investment gains and losses, net, recognized in net income	0	3	9
OCI	2	(9)	7
AOCI, balance at the end of the period	(8)	(10)	(1)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income, Before Tax
AOCI, balance at the beginning of the period	568	29	3,518
Cumulative effect of new accounting principle, before tax				$ 0	$ 0	$ (3,155)
Adjusted AOCI, beginning of period		568	29				363
Investments OCI	436	544	(339)
Pension obligations OCI	(32)	7	(4)
Life deferred acquisition costs, life policy reserves and other OCI	3	(12)	9
Total OCI	407	539	(334)
AOCI, balance at the end of the period	975	568	29
Accumulated Other Comprehensive Income, Income Tax
AOCI, balance at the beginning of the period	120	7	730
Cumulative effect of new account principle, tax				0	0	(652)
Adjusted AOCI, beginning of period		120	7				78
Investments OCI	92	114	(72)
Pension obligations OCI	(7)	2	(1)
Life deferred acquisition costs, life policy reserves and other OCI	1	(3)	2
Total OCI	86	113	(71)
AOCI, balance at the end of the period	206	120	7
Accumulated Other Comprehensive Income, Net of Tax
AOCI, balance at the beginning of the period	448	22	2,788
Unrealized gains reclassified to retained earnings for ASU 2016-01, after tax		0	0	$ 0	$ 0	$ (2,503)	(2,503)
Adjusted AOCI, beginning of period		448	22				$ 285
Investments OCI	344	430	(267)
Pension obligations OCI	(25)	5	(3)
Life deferred acquisition costs, life policy reserves and other OCI	2	(9)	7
Total OCI	321	426	(263)
AOCI, balance at the end of the period	$ 769	$ 448	$ 22

Reinsurance Reinsurance (Writte

Reinsurance Reinsurance (Written Consolidated Property Casualty Insurance Premiums On Assumed and Ceded Business) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-17, Insurance Companies, Reinsurance
Direct premiums earned	$ 5,985	$ 5,681	$ 5,251
Assumed premiums earned	285	199	149
Ceded premiums earned	(290)	(276)	(230)
Incurred loss and loss expenses	4,134	3,638	3,490
Consolidated Property And Casualty Insurance Entity
SEC Schedule, 12-17, Insurance Companies, Reinsurance
Direct premiums written	5,756	5,477	5,018
Assumed premiums written	335	244	173
Ceded premiums written	(227)	(205)	(161)
Net written premiums	5,864	5,516	5,030
Direct premiums earned	5,623	5,340	4,931
Assumed premiums earned	285	199	149
Ceded premiums earned	(217)	(205)	(160)
Earned premiums	5,691	5,334	4,920
Direct incurred loss and loss expenses	3,699	3,402	3,188
Assumed incurred loss and loss expenses	184	117	125
Ceded incurred loss and loss expenses	(46)	(167)	(90)
Incurred loss and loss expenses	$ 3,837	$ 3,352	$ 3,223

Reinsurance (Earned Life Insura

Reinsurance (Earned Life Insurance Premiums On Ceded Business) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Direct premiums earned	$ 5,985	$ 5,681	$ 5,251
Ceded earned premiums	(290)	(276)	(230)
Insurance losses and contract holders' benefits	4,134	3,638	3,490
Life Insurance Segment
Direct premiums earned	362	341	320
Ceded earned premiums	(73)	(71)	(70)
Net earned premiums	289	270	250
Direct contract holders' benefits incurred	359	359	328
Ceded contract holders' benefits incurred	(62)	(73)	(61)
Insurance losses and contract holders' benefits	$ 297	$ 286	$ 267

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
New Accounting Pronouncements or Change in Accounting Principle
Income tax benefit for difference in tax rate	$ 0	$ 0	$ 50
Unrecognized Tax Benefits	34	34	34	$ 0
Income taxes refund received	0	94	$ 0
Net deferred tax assets, valuation allowance	56	41
Deferred tax benefit due to tax rate change			19.90%
Cincinnati Global
New Accounting Pronouncements or Change in Accounting Principle
Net deferred tax assets	56
Net deferred tax assets, valuation allowance	56	41	$ 0
Current year operations	15	(14)
Cincinnati Global
New Accounting Pronouncements or Change in Accounting Principle
Increase (Decrease) of deferred tax assets	15
Current year operations	15
Cincinnati Global | Geographic Distribution, Foreign [Member]
New Accounting Pronouncements or Change in Accounting Principle
Operating Loss Carryforwards	108	127
Cincinnati Global | Geographic Distribution, Domestic [Member]
New Accounting Pronouncements or Change in Accounting Principle
Operating Loss Carryforwards	$ 26	$ 20

Income Taxes (Components Of Def

Income Taxes (Components Of Deferred Tax Assets And Liabilities) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Deferred tax assets:
Unearned premiums	$ 119	$ 113
Loss and loss expense reserves	81	66
Deferred international earnings	45	51
Net operating loss on international earnings	26	4
Other	41	39
Deferred tax assets before valuation allowance	312	273
Valuation allowance for international operations	56	41
Deferred tax assets net of valuation allowance	256	232
Deferred tax liabilities:
Investment gains and other, net	1,240	995
Deferred acquisition costs	143	139
Life policy reserves	121	120
Investments	13	23
Other	38	34
Total gross deferred tax liabilities	1,555	1,311
Net deferred income tax liability	$ 1,299	$ 1,079

Income Taxes Schedule of Income

Income Taxes Schedule of Income before Income Tax (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
United States income before tax									$ 1,521	$ 2,440	$ 251
International income before income taxes									(22)	32	0
Income (loss) before income taxes	$ 1,316	$ 614	$ 1,145	$ (1,576)	$ 781	$ 294	$ 530	$ 867	$ 1,499	$ 2,472	$ 251

Income Taxes The Provision (Ben

Income Taxes The Provision (Benefit) of Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Current federal tax	$ 147	$ 137	$ 11
Current international tax	0	(5)	0
Total current tax	147	132	11
Deferred federal tax	136	338	(47)
Deferred international tax	0	5	0
Deferred income tax expense	136	343	(47)
Total provision (benefit) for income taxes	$ 283	$ 475	$ (36)

Income Taxes (Differences Betwe

Income Taxes (Differences Between The 21 Percent Statutory Income Tax Rate And Effective Income Tax Rate) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Tax at statutory rate:	$ 315	$ 519	$ 53
Tax at statutory rate (percentage):	21.00%	21.00%	21.00%	35.00%
Increase (decrease) resulting from:
Tax-exempt income from municipal bonds	$ (20)	$ (19)	$ (20)
Dividend received exclusion	(17)	(16)	(15)
Effective Income Tax Rate Reconciliation, Tax Accounting Method Changes, Amount	0	0	(50)
Other	5	(9)	(4)
Total provision (benefit) for income taxes	$ 283	$ 475	$ (36)
Tax at statutory rate:
Tax-exempt income from municipal bonds (percentage)	(1.30%)	(0.80%)	(8.00%)
Dividend received exclusion (percentage)	(1.10%)	(0.60%)	(6.00%)
Effective Income Tax Rate Reconciliation, Tax Accounting Method Changes, Percent	0.00%	0.00%	(19.90%)
Deferred tax benefit due to tax rate change			19.90%
Other (percentage)	0.30%	(0.40%)	(1.40%)
Effective tax, percentage	18.90%	19.20%	(14.30%)

Income Taxes - Reconciliation U

Income Taxes - Reconciliation Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Gross unrecognized tax benefits, January 1	$ 34	$ 34	$ 0
Gross increase in prior year positions	0	0	0
Gross decrease in prior year positions	0	0	0
Gross increase in current year positions	0	0	34
Settlements with tax authorities	0	0	0
Lapse of statute of limitations	0	0	0
Gross unrecognized tax benefits, December 31	$ 34	$ 34	$ 34

Income Taxes Reconciliation of

Income Taxes Reconciliation of Cincinnati Global Valuation Allowance (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Valuation Allowance
Valuation allowance at January 1	$ 41
Valuation allowance at December 31	56	$ 41
Cincinnati Global
Valuation Allowance
Valuation allowance at January 1	41	0
Acquisition accounting amount	0	55
Current year operations	15	(14)
Valuation allowance at December 31	$ 56	$ 41

Net Income Per Common Share (Ca

Net Income Per Common Share (Calculations For Basic And Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net Income	$ 1,049	$ 484	$ 909	$ (1,226)	$ 626	$ 248	$ 428	$ 695	$ 1,216	$ 1,997	$ 287
Denominator:
Basic weighted-average common shares outstanding									161.2	163.2	163.2
Diluted weighted-average shares									162.4	165.1	164.5
Earnings per share:
Basic (in usd per share)	$ 6.52	$ 3.01	$ 5.65	$ (7.56)	$ 3.84	$ 1.51	$ 2.62	$ 4.27	$ 7.55	$ 12.24	$ 1.76
Diluted (in usd per share)	$ 6.47	$ 2.99	$ 5.63	$ (7.56)	$ 3.79	$ 1.49	$ 2.59	$ 4.22	$ 7.49	$ 12.10	$ 1.75
Number of anti-dilutive share-based awards									1.4	0	1.3
Stock Options
Denominator:
Effect of stock-based awards									0.7	1.2	0.8
Restricted Stock Units (RSUs)
Denominator:
Effect of stock-based awards									0.5	0.7	0.5

Employee Retirement Benefits (N

Employee Retirement Benefits (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2008
Defined Benefit Plans and Other Postretirement Benefit Plans
Minimum participant age to elect				40 years
Employer discretionary contribution amount	$ 22	$ 19	$ 18
Requisite service period	3 years
Actual return on plan assets	11.40%	24.50%
Pension plan assets at fair value	$ 357	$ 354	318
Employee Stock
Defined Benefit Plans and Other Postretirement Benefit Plans
Pension plan assets, shares	29,776
Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans
Matching contribution to defined contribution plan	6.00%
Pension Plan
Defined Benefit Plans and Other Postretirement Benefit Plans
Percentage of increase decrease in benefit obligations discount rate	0.72%
Change In Net Benefit Cost Discount Rate Assumption	0.94%
Pension Plan | Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans
Cash dividends paid (less than $1 million)	$ 1	1
Supplemental Employee Retirement Plan
Defined Benefit Plans and Other Postretirement Benefit Plans
Accrued employee benefit	$ 10	11
Percentage of increase decrease in benefit obligations discount rate	0.81%
Change In Net Benefit Cost Discount Rate Assumption	0.92%
Expected contribution by employer during 2021	$ 8
Top Hat Savings Plan - Mutual Funds and Common Equities
Defined Benefit Plans and Other Postretirement Benefit Plans
CFC Top Hat Savings Plan	51	45
Top Hat | Top Hat Savings Plan - Mutual Funds and Common Equities
Defined Benefit Plans and Other Postretirement Benefit Plans
CFC Top Hat Savings Plan	51	45
Top Hat | Top Hat Savings Plan - Mutual Funds and Common Equities | Maximum
Defined Benefit Plans and Other Postretirement Benefit Plans
Employer discretionary contribution amount	$ 1	$ 1	$ 1
Domestic Corporate Debt Securities
Defined Benefit Plans and Other Postretirement Benefit Plans
Pension plan assets, shares	202,337	232,113
Pension plan assets, fair value	$ 18	$ 24
Equity Securities
Defined Benefit Plans and Other Postretirement Benefit Plans
Allocation percentage of investments	82.00%
Pension plan assets at fair value	$ 266	260
Equity Securities | Information Technology Sector
Defined Benefit Plans and Other Postretirement Benefit Plans
Allocation percentage of investments	26.00%
Equity Securities | Financial Services Sector
Defined Benefit Plans and Other Postretirement Benefit Plans
Allocation percentage of investments	20.00%
Equity Securities | Industrial Sector
Defined Benefit Plans and Other Postretirement Benefit Plans
Allocation percentage of investments	13.00%
Equity Securities | Healthcare Sector
Defined Benefit Plans and Other Postretirement Benefit Plans
Allocation percentage of investments	12.00%
Equity Securities | All Remaining Sectors
Defined Benefit Plans and Other Postretirement Benefit Plans
Allocation percentage of investments	10.00%
Fixed Maturities
Defined Benefit Plans and Other Postretirement Benefit Plans
Pension plan assets at fair value	$ 60	77
Fixed Maturities | United States Government
Defined Benefit Plans and Other Postretirement Benefit Plans
Allocation percentage of investments	9.00%
Pension plan assets at fair value	$ 31	25
Fixed Maturities | Domestic Corporate Debt Securities
Defined Benefit Plans and Other Postretirement Benefit Plans
Allocation percentage of investments	6.00%
Pension plan assets at fair value	$ 20	27
Fixed Maturities | States, Municipalities and Political Subdivisions
Defined Benefit Plans and Other Postretirement Benefit Plans
Allocation percentage of investments	3.00%
Pension plan assets at fair value	$ 9	25
Cash and Cash Equivalents
Defined Benefit Plans and Other Postretirement Benefit Plans
Pension plan assets at fair value	$ 31	$ 17

Employee Retirement Benefits (W

Employee Retirement Benefits (Weighted-Average Assumptions Used) (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Pension Plan
Weighted average assumptions used to determine benefit obligations
Benefit obligation discount rate	2.68%	3.40%
Summary of the weighted average assumtions used to determine net periodic benefit cost
Discount rate	3.40%	4.34%	3.73%
Expected return on plan assets	7.00%	7.00%	7.25%
Pension Plan | Minimum
Weighted average assumptions used to determine benefit obligations
Benefit obligation rate of compensation increase	2.25%	2.25%
Summary of the weighted average assumtions used to determine net periodic benefit cost
Rate of compensation increase	2.25%	2.25%	2.75%
Pension Plan | Maximum
Weighted average assumptions used to determine benefit obligations
Benefit obligation rate of compensation increase	3.25%	3.25%
Summary of the weighted average assumtions used to determine net periodic benefit cost
Rate of compensation increase	3.25%	3.25%	3.25%
Supplemental Employee Retirement Plan
Weighted average assumptions used to determine benefit obligations
Benefit obligation discount rate	2.52%	3.33%
Summary of the weighted average assumtions used to determine net periodic benefit cost
Discount rate	3.33%	4.25%	3.61%
Supplemental Employee Retirement Plan | Minimum
Weighted average assumptions used to determine benefit obligations
Benefit obligation rate of compensation increase	2.25%	2.25%
Summary of the weighted average assumtions used to determine net periodic benefit cost
Rate of compensation increase	2.25%	2.25%	2.75%
Supplemental Employee Retirement Plan | Maximum
Weighted average assumptions used to determine benefit obligations
Benefit obligation rate of compensation increase	3.25%	3.25%
Summary of the weighted average assumtions used to determine net periodic benefit cost
Rate of compensation increase	3.25%	3.25%	3.25%

Employee Retirement Benefits (B

Employee Retirement Benefits (Benefit Obligation Activity Using An Actuarial Measurement Date For Qualified Plan And SERP) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Change in projected benefit obligation:
Benefit obligation, January 1	$ 350	$ 318
Service cost	9	8	$ 11
Interest cost	12	13	13
Actuarial loss	51	45
Benefits paid	(35)	(34)
Projected benefit obligation, December 31	387	350	318
Change in plan assets:
Fair value of plan assets, January 1	354	318
Actual return on plan assets	34	70
Employer contribution	4	0
Benefits paid	(35)	(34)
Fair value of plan assets, December 31	357	354	$ 318
Unfunded status:
Funded status, December 31	(30)	4
Accumulated benefit obligation	$ 360	$ 327

Employee Retirement Benefits (R

Employee Retirement Benefits (Reconciliation Of The Funded Status For Qualified Plan And SERP) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Retirement Benefits [Abstract]
Other assets		$ 4
Other liabilities	$ (30)
Total	(30)	4
Pension amounts recognized in accumulated other comprehensive income:
Net actuarial loss	41	9
Total	$ 41	$ 9

Employee Retirement Benefits (C

Employee Retirement Benefits (Components Of Net Periodic Benefit Cost As Well As Other Changes In Plan Assets And Benefit Obligations Recognized In Other Comprehensive Income For Qualified Plan And SERP) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Retirement Benefits [Abstract]
Service cost	$ 9	$ 8	$ 11
Interest cost	12	13	13
Expected return on plan assets	(21)	(20)	(22)
Amortization of actuarial loss and prior service cost	3	1	1
Other	3	1	2
Net periodic benefit cost	6	3	5
Current year actuarial (gain) loss	38	(5)	7
Amortization of actuarial loss	(6)	(2)	(3)
Total recognized in other comprehensive (income) loss	32	(7)	4
Total recognized in net periodic benefit cost and other comprehensive (income) loss	$ 38	$ (4)	$ 9

Employee Retirement Benefits (F

Employee Retirement Benefits (Fair Value Hierarchy Of Assets Measured At Fair Value On A Recurring Basis) (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	$ 357	$ 354	$ 318
Fixed Maturities
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	60	77
Fixed Maturities | Level 1
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	31	25
Fixed Maturities | Level 2
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	29	52
Fixed Maturities | Level 3
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	0	0
Fixed Maturities | States, Municipalities and Political Subdivisions
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	9	25
Fixed Maturities | States, Municipalities and Political Subdivisions | Level 1
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	0	0
Fixed Maturities | States, Municipalities and Political Subdivisions | Level 2
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	9	25
Fixed Maturities | States, Municipalities and Political Subdivisions | Level 3
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	0	0
Fixed Maturities | Domestic Corporate Debt Securities
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	20	27
Fixed Maturities | Domestic Corporate Debt Securities | Level 1
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	0	0
Fixed Maturities | Domestic Corporate Debt Securities | Level 2
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	20	27
Fixed Maturities | Domestic Corporate Debt Securities | Level 3
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	0	0
Fixed Maturities | United States Government
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	31	25
Fixed Maturities | United States Government | Level 1
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	31	25
Fixed Maturities | United States Government | Level 2
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	0	0
Fixed Maturities | United States Government | Level 3
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	0	0
Equity Securities
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	266	260
Equity Securities | Level 1
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	266	260
Equity Securities | Level 2
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	0	0
Equity Securities | Level 3
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	0	0
Fixed Maturities And Equity Securities
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	326	337
Fixed Maturities And Equity Securities | Level 1
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	297	285
Fixed Maturities And Equity Securities | Level 2
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	29	52
Fixed Maturities And Equity Securities | Level 3
Defined Benefit Plan Fair Value Disclosure
Pension plan assets at fair value	$ 0	$ 0

Employee Retirement Benefits (E

Employee Retirement Benefits (Expected Future Benefit Payments For Qualified Plan And SERP) (Details) $ in Millions	Dec. 31, 2020USD ($)
Retirement Benefits [Abstract]
Expected future benefit payments, 2021	$ 49
Expected future benefit payments, 2022	22
Expected future benefit payments, 2023	25
Expected future benefit payments, 2024	27
Expected future benefit payments, 2025	29
Expected future benefit payments, 2026 - 2030	$ 163

Statutory Accounting Informat_3

Statutory Accounting Information (Schedule Of Statutory Net Income And Statutory Surplus (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
The Cincinnati Insurance Company
Statutory Accounting Practices
SAP net income (loss)	$ 466	$ 558	$ 626
Capital and surplus	5,838	5,620
The Cincinnati Casualty Company
Statutory Accounting Practices
SAP net income (loss)	14	13	16
Capital and surplus	456	437
The Cincinnati Indemnity Company
Statutory Accounting Practices
SAP net income (loss)	3	3	5
Capital and surplus	115	111
The Cincinnati Specialty Underwriters Insurance Company
Statutory Accounting Practices
SAP net income (loss)	42	62	69
Capital and surplus	528	526
The Cincinnati Life Insurance Company
Statutory Accounting Practices
SAP net income (loss)	27	19	$ 0
Capital and surplus	$ 241	$ 204

Transactions With Affliated Par

Transactions With Affliated Parties (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Related Party Transaction
Payment for commissions	$ 7	$ 8	$ 7
Earned premiums	5,980	5,604	5,170
Affiliated Parties
Related Party Transaction
Earned premiums	$ 45	$ 48	$ 45

Share-Based Associate Compens_3

Share-Based Associate Compensation Plans (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)peers_exceededPeerscompensation_plansshares	Dec. 31, 2019USD ($)Peerspeers_exceededshares	Dec. 31, 2018USD ($)peers_exceededPeersshares
Share-based Compensation Arrangement by Share-based Payment Award
Number of equity compensation plans | compensation_plans	4
Maximum number of shares awarded to each full-time employee for their service | shares	10
Number of peers exceeded | peers_exceeded	8	5	4
Number of peers in peer group | Peers	9	9	9
Share based compensation	$ 25	$ 24	$ 23
Tax benefit from compensation expense	6	6	5
Options exercised, intrinsic value	15	26	15
Options vested, intrinsic value	7	23	6
Unrecognized compensation costs related to non-vested awards	$ 34
Expected weighted-average period to recognize the unrecognized compensation costs related to non-vested awards	1 year 8 months 12 days
Proceeds from stock options exercised		11	9
Shares of common stock granted in period (in shares) | shares	508,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award
Awards exercise peirod	10 years
Awards vesting period	3 years
Proceeds from stock options exercised	$ 7	$ 11	$ 9
Shares repurchased | shares	50,751	103,237	69,649
Shares repurchased, value	$ 5	$ 9	$ 5
Weighted average remaining contractual term	8 years 4 months 17 days
Shares authorized to be granted under the shareholder-approved plans | shares	17,300,000
Shares available for future issuance under the plans | shares	7,100,000
Stock Options | Directors
Share-based Compensation Arrangement by Share-based Payment Award
Shares of common stock granted in period (in shares) | shares	12,928
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	2.15%	2.61%	2.81%
Weighted-average expected term	2 years 10 months 9 days	2 years 10 months 9 days	2 years 10 months 20 days
Risk-free rates	1.30%	2.48%	2.22%
Performance Shares | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award
Shares, Issued | shares	56,722	20,549
Awards vesting period	3 years	3 years
Risk-free rates, minimum	0.00%	0.00%	0.00%
Risk-free rates, maximum	200.00%	200.00%	200.00%
share based performance metric for performance shares	3 years
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Intrinsic Value Aggregate	$ 5	$ 2	$ 6
Service Based Shares | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award
Awards vesting period	3 years
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Intrinsic Value Aggregate	$ 30	$ 25	$ 24

Share-Based Associate Compens_4

Share-Based Associate Compensation Plans (Assumptions Used In Grants Issued) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Stock Options
Weighted-average fair value of options granted during the period	$ 15.45	$ 11.73	$ 9.87
Stock Options | Minimum
Weighted-average expected term	7 years	7 years	7 years
Expected volatility	16.89%	14.49%	15.04%
Dividend yield	2.15%	2.61%	2.98%
Risk-free rates	1.40%	2.62%	2.77%
Stock Options | Maximum
Weighted-average expected term	8 years	8 years	8 years
Expected volatility	17.13%	15.39%	15.10%
Dividend yield	2.15%	2.61%	2.98%
Risk-free rates	1.41%	2.64%	2.83%
Performance Based Shares
Weighted-average expected term	2 years 10 months 9 days	2 years 10 months 9 days	2 years 10 months 20 days
Dividend yield	2.15%	2.61%	2.81%
Risk-free rates	1.30%	2.48%	2.22%
Performance Based Shares | Minimum
Expected volatility	15.88%	15.10%	16.01%
Performance Based Shares | Maximum
Expected volatility	25.13%	25.00%	26.32%

Share-Based Associate Compens_5

Share-Based Associate Compensation Plans (Stock Option Information) (Details) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2020USD ($)$ / sharesshares
Shares
Outstanding at beginning of year (in shares) | shares	3,437
Granted (in shares) | shares	508
Exercised (in shares) | shares	(274)
Forfeited or expired (in shares) | shares	(70)
Outstanding at end of year (in shares) | shares	3,601
Options exercisable at end of period (in shares) | shares	2,509
Weighted-average exercise price
Outstanding at beginning of year (in dollars per share) | $ / shares	$ 63.99
Granted (in dollars per share) | $ / shares	111.53
Exercised (in dollars per share) | $ / shares	41.86
Forfeited or expired (in dollars per share) | $ / shares	55.60
Outstanding at end of year (in dollars per share) | $ / shares	72.55
Options exercisable at end of period (in dollars per share) | $ / shares	$ 63.11
Aggregate intrinsic value
Outstanding at end of year | $	$ 66
Options exercisable at end of period | $	$ 61
Weighted-average remaining contractual life
Outstanding option shares at December 31, 2020	6 years 3 days
Options exercisable at end of period	4 years 11 months 19 days

Share-Based Associate Compens_6

Share-Based Associate Compensation Plans (Restricted Stock Unit Information) (Details) - Restricted Stock Units (RSUs) shares in Thousands	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Service Based Shares
Nonvested shares
Beginning balance (in shares) | shares	783
Granted (in shares) | shares	204
Vested (in shares) | shares	(269)
Forfeited or canceled (in shares) | shares	(22)
Ending balance (in shares) | shares	696
Weighted-average grant-date fair value
Beginning balance (in dollars per share) | $ / shares	$ 70.27
Granted (in dollars per share) | $ / shares	104.81
Vested (in dollars per share) | $ / shares	66.53
Forfeited or canceled (in dollars per share) | $ / shares	78.96
Ending balance (in dollars per share) | $ / shares	$ 81.56
Performance Based Shares
Nonvested shares
Beginning balance (in shares) | shares	165
Granted (in shares) | shares	38
Vested (in shares) | shares	(56)
Forfeited or canceled (in shares) | shares	0
Ending balance (in shares) | shares	147
Weighted-average grant-date fair value
Beginning balance (in dollars per share) | $ / shares	$ 64.23
Granted (in dollars per share) | $ / shares	111.77
Vested (in dollars per share) | $ / shares	43.26
Forfeited or canceled (in dollars per share) | $ / shares	0
Ending balance (in dollars per share) | $ / shares	$ 84.64

Segment Information (Details)

Segment Information (Details) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020USD ($)	Sep. 30, 2020USD ($)	Jun. 30, 2020USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2019USD ($)	Sep. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Mar. 31, 2019USD ($)	Dec. 31, 2020USD ($)segmentindustry	Dec. 31, 2019USD ($)	Dec. 31, 2018USD ($)
Segment Reporting Information
Earned premiums									$ 5,980	$ 5,604	$ 5,170
Fee revenues									11	15	15
Other Income									10	9	5
Total revenues	$ 2,694	$ 2,227	$ 2,714	$ (99)	$ 2,152	$ 1,700	$ 1,913	$ 2,159	7,536	7,924	5,407
Net Investment Income									670	646	619
Investment gains and losses, net									865	1,650	(402)
Income (loss) before income taxes	1,316	$ 614	$ 1,145	$ (1,576)	781	$ 294	$ 530	$ 867	1,499	2,472	251
Identifiable assets	27,542				25,408				$ 27,542	25,408
Number of Industries Operated In | industry									2
Number of Insurance Segments | segment									4
Consolidated Property And Casualty Insurance Entity
Segment Reporting Information
Identifiable assets	3,838				3,437				$ 3,838	3,437
Life Insurance Segment
Segment Reporting Information
Earned premiums									289	270	250
Identifiable assets	1,661				1,516				1,661	1,516
Investments Segment
Segment Reporting Information
Identifiable assets	21,332				19,583				21,332	19,583
Corporate and Other [Member]
Segment Reporting Information
Identifiable assets	$ 711				$ 872				711	872
Operating Segments | Commercial Insurance
Segment Reporting Information
Earned premiums									3,476	3,319	3,218
Fee revenues									3	5	5
Total revenues									3,479	3,324	3,223
Income (loss) before income taxes									64	241	151
Operating Segments | Commercial Insurance | Commercial Casualty Line
Segment Reporting Information
Earned premiums									1,165	1,102	1,075
Operating Segments | Commercial Insurance | Commercial Property Line
Segment Reporting Information
Earned premiums									1,010	958	920
Operating Segments | Commercial Insurance | Commercial Auto Line
Segment Reporting Information
Earned premiums									755	707	664
Operating Segments | Commercial Insurance | Workers' Compensation Line
Segment Reporting Information
Earned premiums									271	300	324
Operating Segments | Commercial Insurance | Other Commercial Lines
Segment Reporting Information
Earned premiums									275	252	235
Operating Segments | Personal Insurance
Segment Reporting Information
Earned premiums									1,463	1,404	1,336
Fee revenues									4	4	5
Total revenues									1,467	1,408	1,341
Income (loss) before income taxes									47	8	(20)
Operating Segments | Personal Insurance | Personal Auto
Segment Reporting Information
Earned premiums									615	621	614
Operating Segments | Personal Insurance | Home Owner Line
Segment Reporting Information
Earned premiums									658	607	563
Operating Segments | Personal Insurance | Other Personal Lines
Segment Reporting Information
Earned premiums									190	176	159
Operating Segments | Excess and Surplus Lines Insurance
Segment Reporting Information
Earned premiums									325	278	234
Fee revenues									2	2	1
Total revenues									327	280	235
Income (loss) before income taxes									34	53	63
Operating Segments | Life Insurance Segment
Segment Reporting Information
Earned premiums									289	270	250
Fee revenues									2	4	4
Total revenues									291	274	254
Income (loss) before income taxes									11	1	8
Operating Segments | Investments Segment
Segment Reporting Information
Total revenues									1,535	2,296	217
Net Investment Income									670	646	619
Investment gains and losses, net									865	1,650	(402)
Income (loss) before income taxes									1,433	2,197	121
Corporate, Non-Segment
Segment Reporting Information
Total revenues									437	342	137
Corporate, Non-Segment | Reinsurance assumed and other non segment
Segment Reporting Information
Earned premiums									427	333	132
Corporate, Non-Segment | Corporate and Other [Member]
Segment Reporting Information
Other Income									10	9	5
Income (loss) before income taxes									$ (90)	$ (28)	$ (72)

Quarterly Supplementary Data (D

Quarterly Supplementary Data (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 2,694	$ 2,227	$ 2,714	$ (99)	$ 2,152	$ 1,700	$ 1,913	$ 2,159	$ 7,536	$ 7,924	$ 5,407
Income (loss) before income taxes	1,316	614	1,145	(1,576)	781	294	530	867	1,499	2,472	251
Net Income (Loss) Attributable to Parent	$ 1,049	$ 484	$ 909	$ (1,226)	$ 626	$ 248	$ 428	$ 695	$ 1,216	$ 1,997	$ 287
Basic (in usd per share)	$ 6.52	$ 3.01	$ 5.65	$ (7.56)	$ 3.84	$ 1.51	$ 2.62	$ 4.27	$ 7.55	$ 12.24	$ 1.76
Diluted (in usd per share)	$ 6.47	$ 2.99	$ 5.63	$ (7.56)	$ 3.79	$ 1.49	$ 2.59	$ 4.22	$ 7.49	$ 12.10	$ 1.75

Summary of Investments Other _2

Summary of Investments Other Than Investments In Related Parties (Details) $ in Millions	Dec. 31, 2020USD ($)
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	$ 15,587
Fair value	0
Balance sheet	21,542
Fixed Maturities
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	11,312
Fair value	12,338
Balance sheet	12,338
Equity Securities
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	3,927
Fair value	8,856
Balance sheet	8,856
Other than Securities Investment
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	348
Fair value	0
Balance sheet	348
States, Municipalities and Political Subdivisions | Fixed Maturities
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	4,604
Fair value	4,997
Balance sheet	4,997
States, Municipalities and Political Subdivisions | Fixed Maturities | Cincinnati Financial Corporation
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	53
Fair value	52
Balance sheet	52
States, Municipalities and Political Subdivisions | Fixed Maturities | The Cincinnati Insurance Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	3,346
Fair value	3,638
Balance sheet	3,638
States, Municipalities and Political Subdivisions | Fixed Maturities | The Cincinnati Casualty Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	219
Fair value	238
Balance sheet	238
States, Municipalities and Political Subdivisions | Fixed Maturities | The Cincinnati Indemnity Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	48
Fair value	52
Balance sheet	52
States, Municipalities and Political Subdivisions | Fixed Maturities | The Cincinnati Life Insurance Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	357
Fair value	387
Balance sheet	387
States, Municipalities and Political Subdivisions | Fixed Maturities | The Cincinnati Specialty Underwriters Insurance Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	580
Fair value	629
Balance sheet	629
States, Municipalities and Political Subdivisions | Fixed Maturities | CSU Producers Resources Inc.
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	1
Fair value	1
Balance sheet	1
United States Government | Fixed Maturities
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	115
Fair value	120
Balance sheet	120
United States Government | Fixed Maturities | The Cincinnati Insurance Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	65
Fair value	70
Balance sheet	70
United States Government | Fixed Maturities | The Cincinnati Casualty Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	1
Fair value	1
Balance sheet	1
United States Government | Fixed Maturities | The Cincinnati Indemnity Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	1
Fair value	1
Balance sheet	1
United States Government | Fixed Maturities | Cincinnati Global
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	48
Fair value	48
Balance sheet	48
Foreign Government | Fixed Maturities
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	29
Fair value	29
Balance sheet	29
Foreign Government | Fixed Maturities | The Cincinnati Insurance Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	10
Fair value	10
Balance sheet	10
Foreign Government | Fixed Maturities | Cincinnati Global
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	19
Fair value	19
Balance sheet	19
Government-Sponsored Enterprises | Fixed Maturities
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	12
Fair value	12
Balance sheet	12
Government-Sponsored Enterprises | Fixed Maturities | Cincinnati Financial Corporation
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	11
Fair value	11
Balance sheet	11
Government-Sponsored Enterprises | Fixed Maturities | Cincinnati Global
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	1
Fair value	1
Balance sheet	1
All Other Corporate Bonds | Fixed Maturities
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	6,552
Fair value	7,180
Balance sheet	7,180
All Other Corporate Bonds | Fixed Maturities | Cincinnati Financial Corporation
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	5
Fair value	5
Balance sheet	5
All Other Corporate Bonds | Fixed Maturities | The Cincinnati Insurance Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	2,964
Fair value	3,211
Balance sheet	3,211
All Other Corporate Bonds | Fixed Maturities | The Cincinnati Casualty Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	103
Fair value	110
Balance sheet	110
All Other Corporate Bonds | Fixed Maturities | The Cincinnati Indemnity Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	30
Fair value	33
Balance sheet	33
All Other Corporate Bonds | Fixed Maturities | The Cincinnati Life Insurance Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	3,192
Fair value	3,540
Balance sheet	3,540
All Other Corporate Bonds | Fixed Maturities | The Cincinnati Specialty Underwriters Insurance Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	189
Fair value	211
Balance sheet	211
All Other Corporate Bonds | Fixed Maturities | Cincinnati Global
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	68
Fair value	69
Balance sheet	69
All Other Corporate Bonds | Fixed Maturities | CSU Producers Resources Inc.
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	1
Fair value	1
Balance sheet	1
Common Stock | Equity Securities
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	3,640
Fair value	8,541
Balance sheet	8,541
Common Stock | Equity Securities | Cincinnati Financial Corporation
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	1,606
Fair value	3,686
Balance sheet	3,686
Common Stock | Equity Securities | The Cincinnati Insurance Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	1,846
Fair value	4,423
Balance sheet	4,423
Common Stock | Equity Securities | The Cincinnati Casualty Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	56
Fair value	146
Balance sheet	146
Common Stock | Equity Securities | The Cincinnati Indemnity Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	17
Fair value	36
Balance sheet	36
Common Stock | Equity Securities | The Cincinnati Specialty Underwriters Insurance Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	96
Fair value	217
Balance sheet	217
Common Stock | Equity Securities | CSU Producers Resources Inc.
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	19
Fair value	33
Balance sheet	33
Nonredeemable Preferred Stock | Equity Securities
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	287
Fair value	315
Balance sheet	315
Nonredeemable Preferred Stock | Equity Securities | Cincinnati Financial Corporation
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	1
Fair value	1
Balance sheet	1
Nonredeemable Preferred Stock | Equity Securities | The Cincinnati Insurance Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	274
Fair value	299
Balance sheet	299
Nonredeemable Preferred Stock | Equity Securities | The Cincinnati Life Insurance Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	12
Fair value	15
Balance sheet	15
Policy Loans | Other than Securities Investment | The Cincinnati Life Insurance Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	33
Fair value	0
Balance sheet	33
Lloyd's and other deposits | Other than Securities Investment | Cincinnati Financial Corporation
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	109
Fair value	0
Balance sheet	109
Lloyd's and other deposits | Other than Securities Investment | Cincinnati Global
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	53
Fair value	0
Balance sheet	53
Limited Partnership | Other than Securities Investment | Cincinnati Financial Corporation
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	31
Fair value	0
Balance sheet	31
Limited Partnership | Other than Securities Investment | The Cincinnati Insurance Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	94
Balance sheet	94
Limited Partnership | Other than Securities Investment | The Cincinnati Life Insurance Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	3
Balance sheet	3
Real Estate | Other than Securities Investment | Cincinnati Financial Corporation
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	5
Balance sheet	5
Real Estate | Other than Securities Investment | The Cincinnati Insurance Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	11
Balance sheet	11
Real Estate | Other than Securities Investment | The Cincinnati Life Insurance Company
Summary Of Investments Other Than Investments In Related Parties Reportable Data
Cost or amortized cost	9
Balance sheet	$ 9

Condensed Financial Statement_2

Condensed Financial Statements Of Parent Company Condensed Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Investments
Fixed maturities, at fair value (amortized cost: 2020—$69; 2019—$49)	$ 12,338	$ 11,698
Equity securities, at fair value (cost: 2020—$1,607; 2019—$1,427)	8,856	7,752
Other invested assets	348	296
Total investments	21,542	19,746
Cash and cash equivalents	900	767	$ 784	$ 657
Investment income receivable	136	133
Land, building and equipment, net, for company use (accumulated depreciation: 2020—$138; 2019—$129)	213	207
Other assets	438	381
Total assets	27,542	25,408
Liabilities
Deferred federal income tax	1,555	1,311
Long-term debt	788	788
Other liabilities	982	928
Total liabilities	16,753	15,544
Shareholders' Equity
Common stock	397	397
Paid-in capital	1,328	1,306
Retained earnings	10,085	9,257
Accumulated other comprehensive income	769	448
Treasury stock at cost	(1,790)	(1,544)
Total shareholders' equity	10,789	9,864	7,833
Total liabilities and shareholders' equity	27,542	25,408
Cincinnati Financial Corporation
Investments
Fixed maturities, at fair value (amortized cost: 2020—$69; 2019—$49)	68	49
Equity securities, at fair value (cost: 2020—$1,607; 2019—$1,427)	3,687	3,069
Other invested assets	145	103
Total investments	3,900	3,221
Cash and cash equivalents	16	197	$ 209	$ 199
Equity in net assets of subsidiaries	7,982	7,424
Investment income receivable	8	7
Land, building and equipment, net, for company use (accumulated depreciation: 2020—$138; 2019—$129)	143	141
Income tax receivable	5	2
Other assets	53	61
Due from subsidiaries	110	107
Total assets	12,217	11,160
Liabilities
Dividends declared but unpaid	97	91
Deferred federal income tax	429	345
Long-term debt	788	788
Other liabilities	114	72
Total liabilities	1,428	1,296
Shareholders' Equity
Common stock	397	397
Paid-in capital	1,328	1,306
Retained earnings	10,085	9,257
Accumulated other comprehensive income	769	448
Treasury stock at cost	(1,790)	(1,544)
Total shareholders' equity	10,789	9,864
Total liabilities and shareholders' equity	$ 12,217	$ 11,160

Condensed Financial Statement_3

Condensed Financial Statements Of Parent Company Condensed Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Condensed Financial Statements, Captions
Fixed maturities, amortized cost	$ 11,312	$ 11,108
Equity securities, cost	3,927	3,581
Land, building and equipment, accumulated depreciation	285	276
Cincinnati Financial Corporation
Condensed Financial Statements, Captions
Fixed maturities, amortized cost	69	49
Equity securities, cost	1,607	1,427
Land, building and equipment, accumulated depreciation	$ 138	$ 129

Condensed Financial Statement_4

Condensed Financial Statements Of Parent Company Condensed Statements Of Income (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Revenues
Investment income, net of expenses									$ 670	$ 646	$ 619
Investment gains and losses, net									865	1,650	(402)
Other revenues									10	9	5
Total revenues	$ 2,694	$ 2,227	$ 2,714	$ (99)	$ 2,152	$ 1,700	$ 1,913	$ 2,159	7,536	7,924	5,407
Expenses
Interest expense									54	53	53
Other expenses									20	23	16
Total expenses									6,037	5,452	5,156
Income (Loss) Before Income Taxes and Earnings of Subsidiaries	1,316	614	1,145	(1,576)	781	294	530	867	1,499	2,472	251
Provision (Benefit) for Income Taxes									283	475	(36)
Net Income	$ 1,049	$ 484	$ 909	$ (1,226)	$ 626	$ 248	$ 428	$ 695	1,216	1,997	287
Amortization of pension actuarial gains and losses and prior service costs									(25)	5	(3)
Other comprehensive income (loss)									321	426	(263)
Comprehensive Income									1,537	2,423	24
Cincinnati Financial Corporation
Revenues
Investment income, net of expenses									81	75	65
Investment gains and losses, net									556	728	(108)
Other revenues									15	15	15
Total revenues									652	818	(28)
Expenses
Interest expense									54	52	52
Other expenses									34	37	31
Total expenses									88	89	83
Income (Loss) Before Income Taxes and Earnings of Subsidiaries									564	729	(111)
Provision (Benefit) for Income Taxes									111	146	(31)
Net Income (Loss) Before Earnings of Subsidiaries									453	583	(80)
Increase in equity of subsidiaries									763	1,414	367
Net Income									1,216	1,997	287
Change in unrealized gain (loss) on securities									0	0	(2)
Amortization of pension actuarial gains and losses and prior service costs									(25)	5	(3)
Other Comprehensive Income (Loss) Before Other Comprehensive Income (Loss) from Subsidiaries									(25)	5	(5)
Other Comprehensive Income (Loss) of subsidiaries									346	421	(258)
Other comprehensive income (loss)									321	426	(263)
Comprehensive Income									$ 1,537	$ 2,423	$ 24

Condensed Financial Statement_5

Condensed Financial Statements Of Parent Company Condensed Statements Of Cash Flows (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash Flows From Operating Activities
Net Income	$ 1,049	$ 484	$ 909	$ (1,226)	$ 626	$ 248	$ 428	$ 695	$ 1,216	$ 1,997	$ 287
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization									81	72	63
Gain (Loss) on Sale of Investments									(851)	(1,640)	408
Changes in:
Investment income receivable									(3)	(1)	2
Current income tax receivable/payable									44	92	(91)
Other assets									(26)	(22)	(1)
Net cash provided by operating activities									1,491	1,208	1,181
Cash Flows From Investing Activities
Sale of fixed maturities									179	102	36
Call or maturity of fixed maturities									912	1,241	1,127
Sale of equity securities									515	203	403
Purchase of fixed maturities									(1,382)	(1,742)	(1,510)
Purchase of equity securities									(699)	(382)	(441)
Investment in buildings and equipment									(20)	(24)	(20)
Change in other invested assets, net									(50)	(72)	(38)
Net cash used in investing activities									(560)	(679)	(451)
Cash Flows From Financing Activities
Payment of cash dividends to shareholders									(375)	(355)	(336)
Shares acquired - share repurchase authorization									(261)	(67)	(125)
Proceeds from stock options exercised										11	9
Other									(110)	(54)	(60)
Net cash used in financing activities									(798)	(546)	(603)
Cash and cash equivalents at beginning of year				767				784	767	784	657
Cash and cash equivalents at end of year	900				767				900	767	784
Cincinnati Financial Corporation
Cash Flows From Operating Activities
Net Income									1,216	1,997	287
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization									12	10	7
Gain (Loss) on Sale of Investments									(552)	(720)	114
Dividends from subsidiaries									550	625	500
Changes in:
Increase in equity of subsidiaries									(763)	(1,414)	(367)
Investment income receivable									(1)	(1)	2
Current federal income taxes									(3)	(1)	14
Current income tax receivable/payable									91	146	(35)
Other assets									0	4	(17)
Other liabilities									1	4	3
Intercompany receivable for operations									34	20	19
Net cash provided by operating activities									585	670	527
Cash Flows From Investing Activities
Sale of fixed maturities									0	3	1
Call or maturity of fixed maturities									1	21	19
Sale of equity securities									307	122	131
Purchase of fixed maturities									(23)	(39)	(17)
Purchase of equity securities									(372)	(237)	(177)
Investment in buildings and equipment									(11)	(13)	(12)
Cash paid for acquisition									0
Change in other invested assets, net									(42)	(67)	(11)
Net cash used in investing activities									(140)	(273)	(66)
Cash Flows From Financing Activities
Payment of cash dividends to shareholders									(375)	(355)	(336)
Shares acquired - share repurchase authorization									(261)	(67)	(125)
Proceeds from stock options exercised									7	11	9
Other									3	2	1
Net cash used in financing activities									(626)	(409)	(451)
Net change in cash and cash equivalents									(181)	(12)	10
Cash and cash equivalents at beginning of year				$ 197				$ 209	197	209	199
Cash and cash equivalents at end of year	$ 16				$ 197				$ 16	$ 197	$ 209

Supplementary Insurance Infor_2

Supplementary Insurance Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Supplementary Insurance Information, by Segment
Deferred policy acquisition costs	$ 805	$ 774	$ 738
Gross future policy benefits, losses, claims and expense losses	9,615	8,947	8,448
Gross unearned premium	2,960	2,788	2,516
Other policy claims and benefits payable	46	35	38
Earned premiums	5,980	5,604	5,170
Investment income, net of expenses	589	571	554
Benefits, claims losses and settlement expense	4,134	3,638	3,490
Amortization of deferred policy acquisition costs	1,106	1,034	946
Underwriting, acquisition and insurance expenses	723	704	651
Net written premiums	5,866	5,518	5,033
Commercial Insurance
Supplementary Insurance Information, by Segment
Deferred policy acquisition costs	317	311	291
Gross future policy benefits, losses, claims and expense losses	4,881	4,569	4,466
Gross unearned premium	1,714	1,665	1,576
Earned premiums	3,476	3,319	3,218
Benefits, claims losses and settlement expense	2,336	2,030	2,049
Amortization of deferred policy acquisition costs	664	631	608
Underwriting, acquisition and insurance expenses	415	422	415
Net written premiums	3,534	3,410	3,245
Personal Insurance
Supplementary Insurance Information, by Segment
Deferred policy acquisition costs	136	130	126
Gross future policy benefits, losses, claims and expense losses	739	687	679
Gross unearned premium	797	757	725
Earned premiums	1,463	1,404	1,336
Benefits, claims losses and settlement expense	977	985	972
Amortization of deferred policy acquisition costs	256	251	242
Underwriting, acquisition and insurance expenses	187	164	147
Net written premiums	1,503	1,435	1,378
Excess and Surplus Lines Insurance
Supplementary Insurance Information, by Segment
Deferred policy acquisition costs	28	25	21
Gross future policy benefits, losses, claims and expense losses	446	351	298
Gross unearned premium	175	152	123
Earned premiums	325	278	234
Benefits, claims losses and settlement expense	199	142	104
Amortization of deferred policy acquisition costs	51	47	39
Underwriting, acquisition and insurance expenses	43	38	29
Net written premiums	348	303	249
Reinsurance assumed and other non segment
Supplementary Insurance Information, by Segment
Deferred policy acquisition costs	61	46	26
Gross future policy benefits, losses, claims and expense losses	611	481	203
Gross unearned premium	273	213	91
Earned premiums	427	333	132
Benefits, claims losses and settlement expense	325	195	98
Amortization of deferred policy acquisition costs	86	57	18
Underwriting, acquisition and insurance expenses	42	42	24
Net written premiums	479	368	158
Property, Liability and Casualty Insurance
Supplementary Insurance Information, by Segment
Deferred policy acquisition costs	542	512	464
Gross future policy benefits, losses, claims and expense losses	6,677	6,088	5,646
Gross unearned premium	2,959	2,787	2,515
Earned premiums	5,691	5,334	4,920
Investment income, net of expenses	431	419	401
Benefits, claims losses and settlement expense	3,837	3,352	3,223
Amortization of deferred policy acquisition costs	1,057	986	907
Underwriting, acquisition and insurance expenses	687	666	615
Net written premiums	5,864	5,516	5,030
Accident and Health Insurance
Supplementary Insurance Information, by Segment
Net written premiums	2	2	3
Life Insurance Segment
Supplementary Insurance Information, by Segment
Deferred policy acquisition costs	263	262	274
Gross future policy benefits, losses, claims and expense losses	2,938	2,859	2,802
Gross unearned premium	1	1	1
Other policy claims and benefits payable	46	35	38
Earned premiums	289	270	250
Investment income, net of expenses	158	152	153
Benefits, claims losses and settlement expense	297	286	267
Amortization of deferred policy acquisition costs	49	48	39
Underwriting, acquisition and insurance expenses	$ 36	$ 38	$ 36

Reinsurance (Details)

Reinsurance (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
SEC Schedule, 12-17, Insurance Companies, Reinsurance
Gross amounts, life insurance in force	$ 111,756	$ 108,130	$ 104,726
Gross amounts	5,985	5,681	5,251
Ceded amounts to other companies, life insurance in force	38,281	38,146	38,584
Ceded premiums earned	290	276	230
Assumed amounts from other companies, life insurance in force	0	0	0
Assumed amounts from other companies	285	199	149
Net amounts, life insurance in force	73,475	69,984	66,142
Premiums Earned, Net	$ 5,980	$ 5,604	$ 5,170
Percentage of amounts assumed to net, life insurance in force	0.00%	0.00%	0.00%
Percentage of amounts assumed to net	4.80%	3.60%	2.90%
Commercial Insurance
SEC Schedule, 12-17, Insurance Companies, Reinsurance
Gross amounts	$ 3,578	$ 3,421	$ 3,314
Ceded premiums earned	109	109	104
Assumed amounts from other companies	7	7	8
Premiums Earned, Net	$ 3,476	$ 3,319	$ 3,218
Percentage of amounts assumed to net	0.20%	0.20%	0.30%
Personal Insurance
SEC Schedule, 12-17, Insurance Companies, Reinsurance
Gross amounts	$ 1,503	$ 1,446	$ 1,372
Ceded premiums earned	41	43	37
Assumed amounts from other companies	1	1	1
Premiums Earned, Net	$ 1,463	$ 1,404	$ 1,336
Percentage of amounts assumed to net	0.10%	0.10%	0.10%
Excess and Surplus Lines Insurance
SEC Schedule, 12-17, Insurance Companies, Reinsurance
Gross amounts	$ 341	$ 292	$ 245
Ceded premiums earned	16	14	11
Assumed amounts from other companies	0	0	0
Premiums Earned, Net	$ 325	$ 278	$ 234
Percentage of amounts assumed to net	0.00%	0.00%	0.00%
Reinsurance assumed and other non segment
SEC Schedule, 12-17, Insurance Companies, Reinsurance
Gross amounts	$ 201	$ 181	$ 0
Ceded premiums earned	51	39	8
Assumed amounts from other companies	277	191	140
Premiums Earned, Net	$ 427	$ 333	$ 132
Percentage of amounts assumed to net	64.90%	57.40%	106.10%
Property, Liability and Casualty Insurance
SEC Schedule, 12-17, Insurance Companies, Reinsurance
Gross amounts	$ 5,623	$ 5,340	$ 4,931
Ceded premiums earned	217	205	160
Assumed amounts from other companies	285	199	149
Premiums Earned, Net	$ 5,691	$ 5,334	$ 4,920
Percentage of amounts assumed to net	5.00%	3.70%	3.00%
Life Insurance Segment
SEC Schedule, 12-17, Insurance Companies, Reinsurance
Gross amounts	$ 362	$ 341	$ 320
Ceded premiums earned	73	71	70
Assumed amounts from other companies	0	0	0
Premiums Earned, Net	$ 289	$ 270	$ 250
Percentage of amounts assumed to net	0.00%	0.00%	0.00%

Valuation And Qualifying Acco_2

Valuation And Qualifying Accounts (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Valuation and allowance roll forward
Beginning balance, January 1	$ 49	$ 6
Ending balance, December 31	78	49	$ 6
Increase to allowance through retained earnings for ASU 2016-13, pretax		3	0	$ 0
Allowance for doubtful receivables
Valuation and allowance roll forward
Beginning balance, January 1	8	6	6
Additions charged to costs and expenses	19	8	6
Deductions	(8)	(6)	(6)
Ending balance, December 31	22	8	6
Deferred tax valuation allowance
Valuation and allowance roll forward
Beginning balance, January 1	41	0	0
Additions charged to costs and expenses	15	55	0
Deductions	0	(14)	0
Ending balance, December 31	$ 56	$ 41	$ 0

Supplementary Information Con_2

Supplementary Information Concerning Property Casualty Insurance Operations (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property Casualty Insurance Underwriters
Deferred policy acquisition costs	$ 542	$ 512	$ 464
Reserves for unpaid claims and claim adjustment expenses	6,677	6,088	5,646
Unearned premiums	2,959	2,787	2,515
Earned premiums	5,691	5,334	4,920
Investment income	431	419	401
Loss and loss expenses incurred related to current accident year	3,968	3,600	3,390
Prior year claims and claims adjustments expense, (favorable) and unfavorable	(131)	(248)	(167)
Amortization of deferred policy acquisition cost	1,057	986	907
Paid loss and loss expenses	3,183	3,260	2,847
Net written premiums	5,864	5,516	5,030
Commercial Insurance
Property Casualty Insurance Underwriters
Deferred policy acquisition costs	317	311	291
Reserves for unpaid claims and claim adjustment expenses	4,881	4,569	4,466
Unearned premiums	1,714	1,665	1,576
Earned premiums	3,476	3,319	3,218
Investment income	0	0	0
Loss and loss expenses incurred related to current accident year	2,431	2,222	2,206
Prior year claims and claims adjustments expense, (favorable) and unfavorable	(95)	(192)	(157)
Amortization of deferred policy acquisition cost	664	631	608
Paid loss and loss expenses	1,969	2,023	1,816
Net written premiums	3,534	3,410	3,245
Personal Insurance
Property Casualty Insurance Underwriters
Deferred policy acquisition costs	136	130	126
Reserves for unpaid claims and claim adjustment expenses	739	687	679
Unearned premiums	797	757	725
Earned premiums	1,463	1,404	1,336
Investment income	0	0	0
Loss and loss expenses incurred related to current accident year	995	1,012	960
Prior year claims and claims adjustments expense, (favorable) and unfavorable	(18)	(27)	13
Amortization of deferred policy acquisition cost	256	251	242
Paid loss and loss expenses	921	966	913
Net written premiums	1,503	1,435	1,378
Excess and Surplus Lines Insurance
Property Casualty Insurance Underwriters
Deferred policy acquisition costs	28	25	21
Reserves for unpaid claims and claim adjustment expenses	446	351	298
Unearned premiums	175	152	123
Earned premiums	325	278	234
Investment income	0	0	0
Loss and loss expenses incurred related to current accident year	192	153	128
Prior year claims and claims adjustments expense, (favorable) and unfavorable	7	(11)	(24)
Amortization of deferred policy acquisition cost	51	47	39
Paid loss and loss expenses	112	90	74
Net written premiums	348	303	249
Reinsurance assumed and other non segment
Property Casualty Insurance Underwriters
Deferred policy acquisition costs	61	46	26
Reserves for unpaid claims and claim adjustment expenses	611	481	203
Unearned premiums	273	213	91
Earned premiums	427	333	132
Investment income	0	0	0
Loss and loss expenses incurred related to current accident year	350	213	96
Prior year claims and claims adjustments expense, (favorable) and unfavorable	(25)	(18)	1
Amortization of deferred policy acquisition cost	86	57	18
Paid loss and loss expenses	181	181	44
Net written premiums	$ 479	$ 368	$ 158