Cincinnati Financial (CINF) 10-Q 26 Apr 17 2017 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2017	Apr. 21, 2017
Document Documentand Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Mar. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q1
Trading Symbol	CINF
Entity Registrant Name	CINCINNATI FINANCIAL CORP
Entity Central Index Key	20,286
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		164,688,145

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Investments
Fixed maturities, at fair value (amortized cost: 2017—$9,981; 2016—$9,799)	$ 10,301	$ 10,085
Equity securities, at fair value (cost: 2017—$3,240; 2016—$2,995)	5,676	5,334
Other invested assets	90	81
Total investments	16,067	15,500
Cash and cash equivalents	543	777
Investment income receivable	123	134
Finance receivable	50	51
Premiums receivable	1,588	1,533
Reinsurance recoverable	544	545
Prepaid reinsurance premiums	52	62
Deferred policy acquisition costs	660	637
Land, building and equipment, net, for company use (accumulated depreciation: 2017—$242; 2016—$237)	181	183
Other assets	170	198
Separate accounts	775	766
Total assets	20,753	20,386
Insurance reserves
Loss and loss expense reserves	5,177	5,085
Life policy and investment contract reserves	2,689	2,671
Unearned premiums	2,377	2,307
Other liabilities	691	786
Deferred income tax	946	865
Note payable	17	20
Long-term debt and capital lease obligations	825	826
Separate accounts	775	766
Total liabilities	13,497	13,326
Commitments and contingent liabilities (Note 12)
Shareholders' Equity
Common stock, par value—$2 per share; (authorized: 2017 and 2016—500 million shares; issued: 2017 and 2016—198.3 million shares)	397	397
Paid-in capital	1,243	1,252
Retained earnings	5,156	5,037
Accumulated other comprehensive income	1,780	1,693
Treasury stock at cost (2017—33.7 million shares and 2016—33.9 million shares)	(1,320)	(1,319)
Total shareholders' equity	7,256	7,060
Total liabilities and shareholders' equity	$ 20,753	$ 20,386

Condensed Consolidated Balance3

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) shares in Millions, $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Fixed maturities, amortized cost	$ 9,981	$ 9,799
Equity securities, cost	3,240	2,995
Land, building and equipment, accumulated depreciation	$ 242	$ 237
Common stock, par value	$ 2	$ 2
Common stock, authorized	500	500
Common stock, issued	198.3	198.3
Common stock, outstanding	198.3	198.3
Treasury stock, shares	33.7	33.9

Condensed Consolidated Statemen

Condensed Consolidated Statements of Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenues [Abstract]
Earned premiums	$ 1,208	$ 1,154
Investment income, net of expenses	149	145
Realized investment gains, net	160	61
Fee revenues	5	3
Other revenues	1	1
Total revenues	1,523	1,364
Benefits and Expenses
Insurance losses and contract holders' benefits	853	724
Underwriting, acquisition and insurance expenses	377	360
Interest expense	13	13
Other operating expenses	4	2
Total benefits and expenses	1,247	1,099
Income Before Income Taxes	276	265
Provision for Income Taxes
Current	40	65
Deferred	35	12
Total provision for income taxes	75	77
Net Income	$ 201	$ 188
Per Common Share
Net income-basic (in USD per share)	$ 1.22	$ 1.14
Net income-diluted (in USD per share)	$ 1.21	$ 1.13

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Net Income	$ 201	$ 188
Change in unrealized gains and losses on investments, net of tax of $46 and $100, respectively	85	190
Amortization of pension actuarial gains and losses and prior service cost, net of tax of $0 and $1, respectively	1	0
Change in life deferred acquisition costs, life policy reserves and other, net of tax of $1 and $(1), respectively	1	(3)
Other comprehensive income	87	187
Comprehensive Income	$ 288	$ 375

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Statement of Comprehensive Income [Abstract]
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	$ 46	$ 100
Other Comprehensive Income Loss, Pension And Other Postretirement Benefit Plans, Net Actuarial Loss And Prior Service Cost Arising During Period, Tax	0	1
Other Comprehensive Income, Change in Life Deferred Acquisition Costs, Life Policy Reserves and Other, Tax	$ 1	$ (1)

Condensed Consolidated Stateme7

Condensed Consolidated Statements of Shareholders' Equity - USD ($) shares in Millions, $ in Millions	Total	Common equities	Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Income	Treasury Stock
Beginning Balance at Dec. 31, 2015		$ 397	$ 1,232	$ 4,762	$ 1,344	$ (1,308)
Share-based awards		0	(10)			18
Share-based compensation			7
Other			1			1
Net Income	$ 188			188
Dividends declared				(79)
Other comprehensive income	187				187
Shares acquired - share repurchase authorization						0
Shares acquired - share-based compensation plans						(5)
Ending Balance at Mar. 31, 2016	6,735	$ 397	1,230	4,871	1,531	(1,294)
Beginning Balance (in shares) at Dec. 31, 2015		163.9
Share-based awards (in shares)		0.5
Shares acquired - share repurchase authorization (in shares)		0
Shares acquired - share-based compensation plans (in shares)		0
Other (in shares)		0
Ending Balance (in shares) at Mar. 31, 2016		164.4
Beginning Balance at Dec. 31, 2016	7,060	$ 397	1,252	5,037	1,693	(1,319)
Share-based awards		0	(18)			17
Share-based compensation			8
Other			1			1
Net Income	201			201
Dividends declared				(82)
Other comprehensive income	87				87
Shares acquired - share repurchase authorization						(15)
Shares acquired - share-based compensation plans						(4)
Ending Balance at Mar. 31, 2017	$ 7,256	$ 397	$ 1,243	$ 5,156	$ 1,780	$ (1,320)
Beginning Balance (in shares) at Dec. 31, 2016	198.3	164.4
Share-based awards (in shares)		0.5
Shares acquired - share repurchase authorization (in shares)		(0.2)
Shares acquired - share-based compensation plans (in shares)		(0.1)
Other (in shares)		0
Ending Balance (in shares) at Mar. 31, 2017	198.3	164.6

Condensed Consolidated Stateme8

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Cash Flows From Operating Activities
Net Income	$ 201	$ 188
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	14	12
Realized investment gains, net	(160)	(61)
Share-based compensation	8	7
Interest credited to contract holders'	13	13
Deferred income tax expense	35	12
Changes in:
Investment income receivable	11	8
Premiums and reinsurance receivable	(44)	(23)
Deferred policy acquisition costs	(25)	(9)
Other assets	(5)	(12)
Loss and loss expense reserves	92	86
Life policy reserves	25	22
Unearned premiums	70	47
Other liabilities	(139)	(90)
Current income tax receivable/payable	40	65
Net cash provided by operating activities	136	265
Cash Flows From Investing Activities
Sale of fixed maturities	12	14
Call or maturity of fixed maturities	249	368
Sale of equity securities	216	132
Purchase of fixed maturities	(403)	(496)
Purchase of equity securities	(313)	(129)
Investment in finance receivables	(5)	(6)
Collection of finance receivables	6	8
Investment in buildings and equipment, net	(2)	(3)
Change in other invested assets, net	(6)	4
Net cash used in investing activities	(246)	(108)
Cash Flows From Financing Activities
Payment of cash dividends to shareholders	(77)	(74)
Payments for Repurchase of Common Stock	(15)	0
Repayments of Notes Payable	(3)	0
Proceeds from stock options exercised	6	9
Contract holders' funds deposited	23	26
Contract holders' funds withdrawn	(43)	(39)
Excess tax benefits on stock-based compensation	0	2
Other	(15)	(12)
Net cash used in financing activities	(124)	(88)
Net change in cash and cash equivalents	(234)	69
Cash and cash equivalents at beginning of year	777	544
Cash and cash equivalents at end of period	543	613
Supplemental Disclosures of Cash Flow Information:
Income taxes paid (refunded)	0	(1)
Noncash Activities
Conversion of securities	4	3
Equipment acquired under capital lease obligations	3	9
Cashless exercise of stock options	4	5
Other assets and other liabilities	$ 73	$ 0

Accounting Policies

Accounting Policies	3 Months Ended
	Mar. 31, 2017
Accounting Policies [Abstract]
Accounting Policies	NOTE 1 — Accounting Policies The condensed consolidated financial statements include the accounts of Cincinnati Financial Corporation and its consolidated subsidiaries, each of which is wholly owned. These statements are presented in conformity with accounting principles generally accepted in the United States of America (GAAP). All intercompany balances and transactions have been eliminated in consolidation. The preparation of financial statements in conformity with GAAP requires us to make estimates and assumptions that affect amounts reported in the financial statements and accompanying notes. Our actual results could differ from those estimates. Our December 31, 2016 , condensed consolidated balance sheet amounts are derived from the audited financial statements but do not include all disclosures required by GAAP. Our March 31, 2017 , condensed consolidated financial statements are unaudited. Certain financial information that is included in annual financial statements prepared in accordance with GAAP is not required for interim reporting and has been condensed or omitted. We believe that we have made all adjustments, consisting only of normal recurring accruals, that are necessary for fair presentation. These condensed consolidated financial statements should be read in conjunction with our consolidated financial statements included in our 2016 Annual Report on Form 10-K. The results of operations for interim periods do not necessarily indicate results to be expected for the full year. Adopted Accounting Updates ASU 2016-07, Investments - Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting In March 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2016-07, Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting. ASU 2016-07 eliminates the requirement to retroactively adjust an investment, results of operations, and retained earnings once an investment qualifies for use of the equity method. It requires the equity method investor to add the cost of acquiring the additional interest in the investee to the current basis of the investor's previously held interest and adopt the equity method of accounting as of the date the investment becomes qualified for equity method accounting without retroactive adjustment. The effective date of ASU 2016-07 was for interim and annual reporting periods beginning after December 15, 2016, and was applied prospectively. The company adopted this ASU effective January 1, 2017 and it did not have a material impact on our company's consolidated financial position, cash flows or results of operations. ASU 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting In March 2016, the FASB issued ASU 2016-09, Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. ASU 2016-09 simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The effective date of ASU 2016-09 was for interim and annual reporting periods beginning after December 15, 2016. The recognition and classification of the excess tax benefit provisions were applied prospectively in the results of operations and statement of cash flows. This adoption resulted in excess tax benefits of $6 million which reduced our current provision for income taxes in our results of operations. The statutory tax withholding classification, which are cash payments made to taxing authorities for shares withheld, were applied retrospectively and reclassified the statutory tax withholding requirements in the statement of cash flows from Other liabilities in operating activities to Other in financing activities. This statutory tax withholding reclassification resulted in $11 million and $8 million being included in financing activities for the three months ended March 31, 2017 and 2016, respectively. There were no cumulative effect adjustments upon adoption of this ASU. Pending Accounting Updates ASU 2014-09 Revenue from Contracts with Customers In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers . ASU 2014-09 requires an entity to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. Insurance contracts do not fall within the scope of this ASU. The effective date of ASU 2014-09 is for interim and annual reporting periods beginning after December 15, 2017. The ASU has not yet been adopted and will not have a material impact on our company’s financial position, cash flows or results of operations. ASU 2016-01, Financial Instruments - Overall (Subtopic 825-10) - Recognition and Measurement of Financial Assets and Financial Liabilities In January 2016, the FASB issued ASU 2016-01, Financial Instruments - Overall (Subtopic 825-10) - Recognition and Measurement of Financial Assets and Financial Liabilities. ASU 2016-01 revises the accounting related to the classification and measurement of investments in equity securities and the presentation of certain fair value changes for financial liabilities measured at fair value. The effective date of ASU 2016-01 is for interim and annual reporting periods beginning after December 15, 2017. The ASU has not yet been adopted. Our results of operations will be impacted as changes in fair value of equity securities will be reported in net income instead of reported in accumulated other comprehensive income. ASU 2016-02, Leases (Topic 842) In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). The main provision of ASU 2016-02 requires the recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases under previous GAAP. The effective date of ASU 2016-02 is for interim and annual reporting periods beginning after December 15, 2018. The ASU has not yet been adopted. Management is currently evaluating the impact on our company’s consolidated financial position, cash flows and results of operations. ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments . ASU 2016-13 amends 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 complexity of credit impairment models and result in a more timely recognition of expected credit losses. The effective date of ASU 2016-13 is for interim and annual reporting periods beginning after December 15, 2019. The ASU has not yet been adopted. Management is currently evaluating the impact on our company's consolidated financial position, cash flows or results of operations. ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments . ASU 2016-15 addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice. The effective date of ASU 2016-15 is for interim and annual reporting periods beginning after December 15, 2017. The ASU has not yet been adopted; however, it is not expected to have a material impact on our company's consolidated financial position, cash flows or results of operations. ASU 2017-07, Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost In March 2017, the FASB issued ASU 2017-07, Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Postretirement Benefit Costs . ASU 2017-07 provides guidance on how to present the components of net periodic benefit costs in the income statement for pension plans and other post-retirement benefit plans. The effective date of ASU 2017-07 is for interim and annual reporting periods beginning after December 15, 2017. The ASU has not yet been adopted; however, it is not expected to have a material impact on our company's consolidated financial position, cash flows or results of operations. ASU 2017-08, Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities In March 2017, the FASB issued ASU 2017-08, Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities. ASU 2017-08 amends guidance on the amortization period of premiums on certain purchased callable debt securities. The amendments shorten the amortization period of premiums on certain purchased callable debt securities to the earliest call date. The amendments should be applied on a modified retrospective basis through a cumulative-effect adjustment to beginning retained earnings. The effective date of ASU 2017-08 is for interim and annual reporting periods beginning after December 15, 2018. The ASU has not yet been adopted. Management is currently evaluating the impact on our company's consolidated financial position, cash flows or results of operations.

Investments

Investments	3 Months Ended
	Mar. 31, 2017
Investments [Abstract]
Investments	Investments The following table provides cost or amortized cost, gross unrealized gains, gross unrealized losses and fair value for our fixed-maturity and equity securities: (Dollars in millions) Cost or amortized cost Gross unrealized Fair value At March 31, 2017 gains losses Fixed maturity securities: Corporate $ 5,570 $ 262 $ 17 $ 5,815 States, municipalities and political subdivisions 3,879 110 37 3,952 Commercial mortgage-backed 282 6 1 287 Government-sponsored enterprises 219 — 3 216 United States government 16 — — 16 Foreign government 10 — — 10 Convertibles and bonds with warrants attached 5 — — 5 Subtotal 9,981 378 58 10,301 Equity securities: Common equities 3,051 2,411 9 5,453 Nonredeemable preferred equities 189 34 — 223 Subtotal 3,240 2,445 9 5,676 Total $ 13,221 $ 2,823 $ 67 $ 15,977 At December 31, 2016 Fixed maturity securities: Corporate $ 5,555 $ 252 $ 26 $ 5,781 States, municipalities and political subdivisions 3,770 100 42 3,828 Commercial mortgage-backed 282 7 2 287 Government-sponsored enterprises 167 — 3 164 United States government 10 — — 10 Foreign government 10 — — 10 Convertibles and bonds with warrants attached 5 — — 5 Subtotal 9,799 359 73 10,085 Equity securities: Common equities 2,812 2,320 9 5,123 Nonredeemable preferred equities 183 28 — 211 Subtotal 2,995 2,348 9 5,334 Total $ 12,794 $ 2,707 $ 82 $ 15,419 The net unrealized investment gains in our fixed-maturity portfolio at March 31, 2017 , 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 March 31, 2017 , and December 31, 2016 . The seven largest unrealized investment gains in our common stock portfolio are from JP Morgan Chase & Co. (NYSE:JPM), Honeywell International Incorporated (NYSE:HON), Apple Inc. (Nasdaq:AAPL), Hasbro Inc. (Nasdaq:HAS), Microsoft Corporation (Nasdaq: MSFT), Exxon Mobil Corporation (NYSE:XOM), and Johnson & Johnson (NYSE:JNJ), which had a combined gross unrealized gain of $760 million . At March 31, 2017 , Apple Inc. was our largest single equity holding with a fair value of $201 million , which was 3.7 percent of our publicly traded common equities portfolio and 1.3 percent of the total investment portfolio. The table below provides fair values and gross 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 Fair value Unrealized losses Fair value Unrealized losses Fair value Unrealized losses At March 31, 2017 Fixed maturity securities: Corporate $ 381 $ 10 $ 136 $ 7 $ 517 $ 17 States, municipalities and political subdivisions 883 37 — — 883 37 Commercial mortgage-backed securities 75 1 2 — 77 1 Government-sponsored enterprises 165 3 — — 165 3 United States government 6 — — — 6 — Subtotal 1,510 51 138 7 1,648 58 Equity securities: Common equities 236 9 4 — 240 9 Subtotal 236 9 4 — 240 9 Total $ 1,746 $ 60 $ 142 $ 7 $ 1,888 $ 67 At December 31, 2016 Fixed maturity securities: Corporate $ 733 $ 15 $ 189 $ 11 $ 922 $ 26 States, municipalities and political subdivisions 989 42 — — 989 42 Commercial mortgage-backed 89 2 2 — 91 2 Government-sponsored enterprises 155 3 — — 155 3 United States government 6 — — — 6 — Subtotal 1,972 62 191 11 2,163 73 Equity securities: Common equities 103 9 — — 103 9 Nonredeemable preferred equities 4 — — — 4 — Subtotal 107 9 — — 107 9 Total $ 2,079 $ 71 $ 191 $ 11 $ 2,270 $ 82 Contractual maturity dates for fixed-maturity investments were: (Dollars in millions) Amortized cost Fair value % of fair value At March 31, 2017 Maturity dates: Due in one year or less $ 655 $ 669 6.5 % Due after one year through five years 2,764 2,911 28.3 Due after five years through ten years 3,862 3,981 38.6 Due after ten years 2,700 2,740 26.6 Total $ 9,981 $ 10,301 100.0 % Actual maturities may differ from contractual maturities when there is a right to call or prepay obligations with or without call or prepayment penalties. The following table provides investment income, realized investment gains and losses, the change in unrealized investment gains and losses: (Dollars in millions) Three months ended March 31, 2017 2016 Investment income: Interest $ 111 $ 109 Dividends 39 37 Other 1 1 Total 151 147 Less investment expenses 2 2 Total $ 149 $ 145 Realized investment gains and losses: Fixed maturities: Gross realized gains $ 10 $ 3 Gross realized losses — (1 ) Other-than-temporary impairments — (2 ) Equity securities: Gross realized gains 153 62 Gross realized losses (4 ) (1 ) Other-than-temporary impairments — — Other 1 — Total $ 160 $ 61 Change in unrealized investment gains and losses: Fixed maturities $ 34 $ 116 Equity securities 97 174 Income tax (provision) benefit (46 ) (100 ) Total $ 85 $ 190 During the three months ended March 31, 2017 , there were no equity securities and no fixed-maturity securities other-than-temporarily impaired. During the three months ended March 31, 2016, there were no equity securities and two fixed-maturity securities other-than-temporarily impaired. There were no credit losses on fixed-maturity securities for which a portion of other-than-temporary impairment (OTTI) has been recognized in other comprehensive income for the three months ended March 31, 2017 and 2016 . At March 31, 2017 , 22 fixed-maturity investments with a total unrealized loss of $7 million had been in an unrealized loss position for 12 months or more. Of that total, no fixed-maturity investment had a fair value below 70 percent of amortized cost. At March 31, 2017 , one equity investment with a total unrealized loss of less than $1 million had been in an unrealized loss position for 12 months or more. There were no equity investments with a fair value below 70 percent of amortized cost. At December 31, 2016 , 32 fixed-maturity investments with a total unrealized loss of $11 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 percent of amortized cost. There were no equity security investments in an unrealized loss position for 12 months or more as of December 31, 2016 .

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements In accordance with accounting guidance for fair value measurements and disclosures, we categorized our financial instruments, based on the priority of the observable and market-based data for the valuation technique used, into a three-level 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, 2016 , and ultimately management determines fair value. See our 2016 Annual Report on Form 10-K, Item 8, Note 3, Fair Value Measurements, Page 132, for information on characteristics and valuation techniques used in determining fair value. Fair Value Disclosures for Assets The following tables illustrate the fair value hierarchy for those assets measured at fair value on a recurring basis at March 31, 2017 , and December 31, 2016 . We do not have any material liabilities carried at fair value. There were no transfers between Level 1 and Level 2. (Dollars in millions) Quoted prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) Total At March 31, 2017 Fixed maturities, available for sale: Corporate $ — $ 5,814 $ 1 $ 5,815 States, municipalities and political subdivisions — 3,952 — 3,952 Commercial mortgage-backed — 287 — 287 Government-sponsored enterprises — 216 — 216 United States government 16 — — 16 Foreign government — 10 — 10 Convertibles and bonds with warrants attached — 5 — 5 Subtotal 16 10,284 1 10,301 Common equities, available for sale 5,453 — — 5,453 Nonredeemable preferred equities, available for sale — 223 — 223 Separate accounts taxable fixed maturities — 764 — 764 Top Hat savings plan mutual funds and common 27 — — 27 Total $ 5,496 $ 11,271 $ 1 $ 16,768 At December 31, 2016 Fixed maturities, available for sale: Corporate $ — $ 5,703 $ 78 $ 5,781 States, municipalities and political subdivisions — 3,828 — 3,828 Commercial mortgage-backed — 287 — 287 Government-sponsored enterprises — 164 — 164 United States government 10 — — 10 Foreign government — 10 — 10 Convertibles and bonds with warrants attached — 5 — 5 Subtotal 10 9,997 78 10,085 Common equities, available for sale 5,123 — — 5,123 Nonredeemable preferred equities, available for sale — 211 — 211 Separate accounts taxable fixed maturities — 750 — 750 Top Hat savings plan mutual funds and common equity (included in Other assets) 24 — — 24 Total $ 5,157 $ 10,958 $ 78 $ 16,193 Each financial instrument that was deemed to have significant unobservable inputs when determining valuation is identified in the following tables by security type with a summary of changes in fair value as of March 31, 2017 . Total Level 3 assets continue to be less than 1 percent of financial assets measured at fair value in the condensed consolidated balance sheets. Assets presented in the table below were valued based primarily on broker/dealer quotes for which there is a lack of transparency as to inputs used to develop the valuations. Transfers out of Level 3 included situations where a broker quote was used without observable inputs or data that could be corroborated by our pricing vendors in the prior period and significant other observable inputs were identified in the current period. The quantitative detail of these unobservable inputs is neither provided nor reasonably available to us. The following table provides the change in Level 3 assets for the three months ended March 31 : (Dollars in millions) Asset fair value measurements using significant unobservable inputs Corporate fixed maturities Taxable fixed maturities - separate accounts Nonredeemable preferred equities Total Beginning balance, January 1, 2017 $ 78 $ — $ — $ 78 Total gains or losses (realized/unrealized): Included in net income — — — — Included in other comprehensive income — — — — Purchases — — — — Sales — — — — Transfers into Level 3 — — — — Transfers out of Level 3 (77 ) — — (77 ) Ending balance, March 31, 2017 $ 1 $ — $ — $ 1 Beginning balance, January 1, 2016 $ 51 $ 1 $ 3 $ 55 Total gains or losses (realized/unrealized): Included in net income — — — — Included in other comprehensive income — — (1 ) (1 ) Purchases 5 — — 5 Sales — — — — Transfers into Level 3 — — — — Transfers out of Level 3 (5 ) — — (5 ) Ending balance, March 31, 2016 $ 51 $ 1 $ 2 $ 54 Additional disclosures for the Level 3 category are not material. Fair Value Disclosures 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 condensed consolidated financial statements. This table summarizes the book value and principal amounts of our long-term debt: (Dollars in millions) Book value Principal amount Interest rate Year of issue March 31, December 31, March 31, December 31, 2017 2016 2017 2016 6.900 % 1998 Senior debentures, due 2028 $ 26 $ 26 $ 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 $ 787 $ 787 $ 793 $ 793 The following table shows fair values of our note payable and long-term debt: (Dollars in millions) Quoted prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) Total At March 31, 2017 Note payable $ — $ 17 $ — $ 17 6.900% senior debentures, due 2028 — 33 — 33 6.920% senior debentures, due 2028 — 497 — 497 6.125% senior notes, due 2034 — 450 — 450 Total $ — $ 997 $ — $ 997 At December 31, 2016 Note payable $ — $ 20 $ — $ 20 6.900% senior debentures, due 2028 — 33 — 33 6.920% senior debentures, due 2028 — 488 — 488 6.125% senior notes, due 2034 — 435 — 435 Total $ — $ 976 $ — $ 976 The following table shows the fair value of our life policy loans included in other invested assets: (Dollars in millions) Quoted prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) Total At March 31, 2017 Life policy loans $ — $ — $ 40 $ 40 At December 31, 2016 Life policy loans $ — $ — $ 40 $ 40 Outstanding principal and interest for these life policy loans totaled $30 million and $31 million at March 31, 2017 , and December 31, 2016 , respectively. The following table shows fair values of our deferred annuities and structured settlements included in life policy and investment contract reserves: (Dollars in millions) Quoted prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) Total At March 31, 2017 Deferred annuities $ — $ — $ 844 $ 844 Structured settlements — 203 — 203 Total $ — $ 203 $ 844 $ 1,047 At December 31, 2016 Deferred annuities $ — $ — $ 839 $ 839 Structured settlements — 206 — 206 Total $ — $ 206 $ 839 $ 1,045 Recorded reserves for the deferred annuities were $858 million and $861 million at March 31, 2017 , and December 31, 2016, respectively. Recorded reserves for the structured settlements were $166 million and $170 million at March 31, 2017 , and December 31, 2016 , respectively.

Property Casualty Loss and Loss

Property Casualty Loss and Loss Expenses	3 Months Ended
	Mar. 31, 2017
Premiums Written, Net [Abstract]
Property Casualty Loss And Loss Expenses	Property Casualty Loss and Loss Expenses This table summarizes activity for our consolidated property casualty loss and loss expense reserves: (Dollars in millions) Three months ended March 31, 2017 2016 Gross loss and loss expense reserves, beginning of period $ 5,035 $ 4,660 Less reinsurance recoverable 298 281 Net loss and loss expense reserves, beginning of period 4,737 4,379 Net incurred loss and loss expenses related to: Current accident year 826 723 Prior accident years (38 ) (62 ) Total incurred 788 661 Net paid loss and loss expenses related to: Current accident year 185 146 Prior accident years 509 416 Total paid 694 562 Net loss and loss expense reserves, end of period 4,831 4,478 Plus reinsurance recoverable 297 272 Gross loss and loss expense reserves, end of period $ 5,128 $ 4,750 We use actuarial methods, models 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 incurred but not reported (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 accounting 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. The reserve for loss and loss expenses in the condensed consolidated balance sheets also included $49 million at March 31, 2017 , and $54 million at March 31, 2016 , for certain life and health loss and loss expense reserves. For the three months ended March 31, 2017 , we experienced $38 million of favorable development on prior accident years, including $11 million of favorable development in commercial lines, $10 million of favorable development in personal lines, $13 million of favorable development in excess and surplus lines and $4 million of favorable development in our reinsurance assumed operations. This included $11 million from favorable development of catastrophe losses for the three months ended March 31, 2017 . For the three months ended March 31, 2017, we recognized favorable reserve development of $18 million for the workers' compensation line, $10 million for the commercial property line and $8 million for the other commercial lines due to reduced uncertainty of prior accident year loss and loss adjustment expense for these lines. For the three months ended March 31, 2017, we recognized unfavorable reserve development of $15 million for the commercial casualty line and $10 million for the commercial auto line. The unfavorable reserve development for commercial casualty reflected higher than usual large loss activity. Commercial auto developed unfavorably due to higher loss cost effects in recent accident years, resulting in an increase of our reserve estimate for claims that have not yet been settled. For the three months ended March 31, 2016 , we experienced $62 million of favorable development on prior accident years, including $29 million of favorable development in commercial lines, $18 million of favorable development in personal lines, $14 million of favorable development in excess and surplus lines, and $1 million of favorable development in our reinsurance assumed operations. This included $7 million from favorable development of catastrophe losses for the three months ended March 31, 2016 . We recognized favorable reserve development during the three months ended March 31, 2016 , of $13 million for the workers' compensation line, $8 million for the commercial property line, $13 million for the other commercial lines and $8 million for the homeowner line due to reduced uncertainty of prior accident year loss and loss adjustment expenses for these lines. Our commercial auto line developed unfavorably by $8 million for the three months ended March 31, 2016 , due to higher loss cost effects in recent accident years, resulting in an increase of our reserve estimate for claims that have not yet been settled.

Life Policy and Investment Cont

Life Policy and Investment Contract Reserves	3 Months Ended
	Mar. 31, 2017
Liability for Future Policy Benefits [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 economic conditions. We establish reserves for the company’s deferred annuity, universal life 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) March 31, December 31, 2016 Life policy reserves: Ordinary/traditional life $ 1,026 $ 1,011 Other 45 45 Subtotal 1,071 1,056 Investment contract reserves: Deferred annuities 858 861 Universal life 588 578 Structured settlements 166 170 Other 6 6 Subtotal 1,618 1,615 Total life policy and investment contract reserves $ 2,689 $ 2,671

Deferred Acquisition Costs

Deferred Acquisition Costs	3 Months Ended
	Mar. 31, 2017
Deferred Costs [Abstract]
Deferred 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) Three months ended March 31, 2017 2016 Property casualty: Deferred policy acquisition costs asset, beginning of period $ 408 $ 388 Capitalized deferred policy acquisition costs 226 210 Amortized deferred policy acquisition costs (206 ) (201 ) Deferred policy acquisition costs asset, end of period $ 428 $ 397 Life: Deferred policy acquisition costs asset, beginning of period $ 229 $ 228 Capitalized deferred policy acquisition costs 13 12 Amortized deferred policy acquisition costs (8 ) (11 ) Amortized shadow deferred policy acquisition costs (2 ) (8 ) Deferred policy acquisition costs asset, end of period $ 232 $ 221 Consolidated: Deferred policy acquisition costs asset, beginning of period $ 637 $ 616 Capitalized deferred policy acquisition costs 239 222 Amortized deferred policy acquisition costs (214 ) (212 ) Amortized shadow deferred policy acquisition costs (2 ) (8 ) Deferred policy acquisition costs asset, end of period $ 660 $ 618 No premium deficiencies were recorded in the condensed consolidated statements of income, 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.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income	3 Months Ended
	Mar. 31, 2017
Accumulated Other Comprehensive Income [Abstract]
Comprehensive Income (Loss) Note	Accumulated Other Comprehensive Income Accumulated other comprehensive income (AOCI) includes changes in unrealized gains and losses on investments, changes in pension obligations and changes in life deferred acquisition costs, life policy reserves and other as follows: (Dollars in millions) Three months ended March 31, 2017 2016 Before tax Income tax Net Before tax Income tax Net Investments: AOCI, beginning of period $ 2,625 $ 908 $ 1,717 $ 2,094 $ 722 $ 1,372 OCI before realized gains recognized in net income 290 102 188 351 121 230 Realized gains recognized in net income (159 ) (56 ) (103 ) (61 ) (21 ) (40 ) OCI 131 46 85 290 100 190 AOCI, end of period $ 2,756 $ 954 $ 1,802 $ 2,384 $ 822 $ 1,562 Pension obligations: AOCI, beginning of period $ (26 ) $ (8 ) $ (18 ) $ (42 ) $ (14 ) $ (28 ) OCI excluding amortization recognized in net income — — — — — — Amortization recognized in net income 1 — 1 1 1 — OCI 1 — 1 1 1 — AOCI, end of period $ (25 ) $ (8 ) $ (17 ) $ (41 ) $ (13 ) $ (28 ) Life deferred acquisition costs, life policy reserves and other: AOCI, beginning of period $ (9 ) $ (3 ) $ (6 ) $ 1 $ 1 $ — OCI before realized gains recognized in net income 3 2 1 (4 ) (1 ) (3 ) Realized gains recognized in net income (1 ) (1 ) — — — — OCI 2 1 1 (4 ) (1 ) (3 ) AOCI, end of period $ (7 ) $ (2 ) $ (5 ) $ (3 ) $ — $ (3 ) Summary of AOCI: AOCI, beginning of period $ 2,590 $ 897 $ 1,693 $ 2,053 $ 709 $ 1,344 Investments OCI 131 46 85 290 100 190 Pension obligations OCI 1 — 1 1 1 — Life deferred acquisition costs, life policy reserves and other OCI 2 1 1 (4 ) (1 ) (3 ) Total OCI 134 47 87 287 100 187 AOCI, end of period $ 2,724 $ 944 $ 1,780 $ 2,340 $ 809 $ 1,531 Investments realized gains and life deferred acquisition costs, life policy reserves and other realized gains are recorded in the realized investment gains, net, line item in the condensed consolidated statements of income. Amortization on pension obligations is recorded in the insurance losses and contract holders' benefits and underwriting, acquisition and insurance expenses in the condensed consolidated statements of income.

Reinsurance

Reinsurance	3 Months Ended
	Mar. 31, 2017
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 includes our net written consolidated property casualty insurance premiums on assumed and ceded business: (Dollars in millions) Three months ended March 31, 2017 2016 Direct written premiums $ 1,226 $ 1,161 Assumed written premiums 33 21 Ceded written premiums (28 ) (35 ) Net written premiums $ 1,231 $ 1,147 Our condensed consolidated statements of income include earned consolidated property casualty insurance premiums on assumed and ceded business: (Dollars in millions) Three months ended March 31, 2017 2016 Direct earned premiums $ 1,163 $ 1,119 Assumed earned premiums 27 15 Ceded earned premiums (39 ) (38 ) Earned premiums $ 1,151 $ 1,096 Our condensed consolidated statements of income include incurred consolidated property casualty insurance loss and loss expenses on assumed and ceded business: (Dollars in millions) Three months ended March 31, 2017 2016 Direct incurred loss and loss expenses $ 788 $ 648 Assumed incurred loss and loss expenses 15 10 Ceded incurred loss and loss expenses (15 ) 3 Incurred loss and loss expenses $ 788 $ 661 Our change in ceded incurred compared to prior years resulted from an increase in current accident year losses. Our life insurance company purchases reinsurance for protection of a portion of the 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. Our condensed consolidated statements of income include earned life insurance premiums on ceded business: (Dollars in millions) Three months ended March 31, 2017 2016 Direct earned premiums $ 74 $ 71 Ceded earned premiums (17 ) (13 ) Earned premiums $ 57 $ 58 Our condensed consolidated statements of income include life insurance contract holders' benefits incurred on ceded business: (Dollars in millions) Three months ended March 31, 2017 2016 Direct contract holders' benefits incurred $ 76 $ 76 Ceded contract holders' benefits incurred (11 ) (13 ) Contract holders' benefits incurred $ 65 $ 63 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	3 Months Ended
	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes As of March 31, 2017 , and December 31, 2016 , we had no liability for unrecognized tax benefits. The differences between the 35 percent statutory federal income tax rate and our effective income tax rate were as follows: (Dollars in millions) Three months ended March 31, 2017 2016 Tax at statutory rate: $ 97 35.0 % $ 93 35.0 % Increase (decrease) resulting from: Tax-exempt income from municipal bonds (9 ) (3.3 ) (9 ) (3.4 ) Dividend received exclusion (8 ) (2.9 ) (8 ) (3.0 ) Other (5 ) (1.6 ) 1 0.5 Provision for income taxes $ 75 27.2 % $ 77 29.1 % The provision for federal income taxes is based upon filing a consolidated income tax return for the company and its subsidiaries. Included in Other above is the adoption of ASU 2016-09, Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting , which decreased both the provision for income taxes and the effective income tax rate by $6 million and 2.2 percent , respectively. As of March 31, 2017 , we had no operating or capital loss carry forwards.

Net Income Per Common Share

Net Income Per Common Share	3 Months Ended
	Mar. 31, 2017
Earnings Per Share [Abstract]
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) Three months ended March 31, 2017 2016 Numerator: Net income—basic and diluted $ 201 $ 188 Denominator: Basic weighted-average common shares outstanding 164.6 164.2 Effect of share-based awards: Stock options 1.1 1.0 Nonvested shares 0.8 0.8 Diluted weighted-average shares 166.5 166.0 Earnings per share: Basic $ 1.22 $ 1.14 Diluted 1.21 1.13 Number of anti-dilutive share-based awards 0.7 0.4 The sources of dilution of our common shares are certain equity-based awards. See our 2016 Annual Report on Form 10-K, Item 8, Note 17, Share-Based Associate Compensation Plans, Page 160, for information about equity-based awards. The above table shows the number of anti-dilutive share-based awards for the three months ended March 31, 2017 and 2016 . We did not include these share-based awards in the computation of net income per common share (diluted) because their exercise would have anti-dilutive effects.

Employee Retirement Benefits

Employee Retirement Benefits	3 Months Ended
	Mar. 31, 2017
Compensation and Retirement Disclosure [Abstract]
Employee Retirement Benefits	Employee Retirement Benefits The following summarizes the components of net periodic benefit cost for our qualified and supplemental pension plans: (Dollars in millions) Three months ended March 31, 2017 2016 Service cost $ 3 $ 3 Interest cost 3 3 Expected return on plan assets (5 ) (5 ) Amortization of actuarial loss and prior service cost 1 1 Net periodic benefit cost $ 2 $ 2 See our 2016 Annual Report on Form 10-K, Item 8, Note 13, Employee Retirement Benefits, Page 155, for information on our retirement benefits. We made matching contributions totaling $6 million and $4 million to our 401(k) and Top Hat savings plans during the first quarter of 2017 and 2016, respectively. We contributed $5 million to our qualified pension plan during the first three months of 2017.

Commitments and Contingent Liab

Commitments and Contingent Liabilities	3 Months Ended
	Mar. 31, 2017
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. 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 state or 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. On a quarterly basis, we review these outstanding matters. Under current accounting guidance, we establish accruals when it is probable that a loss has been incurred and we can reasonably estimate its potential exposure. The company accounts for such probable and estimable losses, if any, through the establishment of legal expense reserves. Based on our quarterly review, we believe that our accruals for probable and estimable losses are reasonable and that the amounts accrued do not have a material effect on our consolidated financial condition or results of operations. However, if any one or more of these matters results in a judgment against us or settlement for an amount that is significantly greater than the amount accrued, the resulting liability could have a material effect on the company's consolidated results of operations or cash flows. Based on our most recent review, our estimate of losses for any other matters for which the risk of loss is not probable, but more than remote, is immaterial.

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2017
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 and Cincinnati Re, our reinsurance assumed operations. See our 2016 Annual Report on Form 10-K, Item 8, Note 18, Segment Information, Page 163, for a description of revenue, income or loss before income taxes and identifiable assets for each of the five segments. Segment information is summarized in the following table: (Dollars in millions) Three months ended March 31, 2017 2016 Revenues: Commercial lines insurance Commercial casualty $ 265 $ 257 Commercial property 223 214 Commercial auto 155 144 Workers' compensation 84 89 Other commercial 54 56 Commercial lines insurance premiums 781 760 Fee revenues 1 1 Total commercial lines insurance 782 761 Personal lines insurance Personal auto 141 131 Homeowner 125 119 Other personal 34 33 Personal lines insurance premiums 300 283 Fee revenues 2 1 Total personal lines insurance 302 284 Excess and surplus lines insurance 48 43 Life insurance premiums 57 58 Fee revenues 2 1 Total life insurance 59 59 Investments Investment income, net of expenses 149 145 Realized investment gains, net 160 61 Total investment revenue 309 206 Other Cincinnati Re insurance premiums 22 10 Other 1 1 Total other revenues 23 11 Total revenues $ 1,523 $ 1,364 Income (loss) before income taxes: Insurance underwriting results Commercial lines insurance $ (2 ) $ 50 Personal lines insurance (15 ) 28 Excess and surplus lines insurance 18 17 Life insurance — (1 ) Investments 286 184 Other (11 ) (13 ) Total income before income taxes $ 276 $ 265 Identifiable assets: March 31, December 31, 2016 Property casualty insurance $ 2,886 $ 2,967 Life insurance 1,359 1,366 Investments 16,123 15,569 Other 385 484 Total $ 20,753 $ 20,386

Accounting Policies Pending Acc

Accounting Policies Pending Accounting Updates (Policies)	3 Months Ended
	Mar. 31, 2017
Accounting Policies [Abstract]
Adopted Accounting Updates and Pending Accounting Updates	Adopted Accounting Updates ASU 2016-07, Investments - Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting In March 2016, the Financial Accounting Standards Board (FASB) issued Accounting Standards Update (ASU) 2016-07, Equity Method and Joint Ventures (Topic 323): Simplifying the Transition to the Equity Method of Accounting. ASU 2016-07 eliminates the requirement to retroactively adjust an investment, results of operations, and retained earnings once an investment qualifies for use of the equity method. It requires the equity method investor to add the cost of acquiring the additional interest in the investee to the current basis of the investor's previously held interest and adopt the equity method of accounting as of the date the investment becomes qualified for equity method accounting without retroactive adjustment. The effective date of ASU 2016-07 was for interim and annual reporting periods beginning after December 15, 2016, and was applied prospectively. The company adopted this ASU effective January 1, 2017 and it did not have a material impact on our company's consolidated financial position, cash flows or results of operations. ASU 2016-09, Compensation - Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting In March 2016, the FASB issued ASU 2016-09, Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting. ASU 2016-09 simplifies several aspects of the accounting for share-based payment transactions, including the income tax consequences, classification of awards as either equity or liabilities, and classification on the statement of cash flows. The effective date of ASU 2016-09 was for interim and annual reporting periods beginning after December 15, 2016. The recognition and classification of the excess tax benefit provisions were applied prospectively in the results of operations and statement of cash flows. This adoption resulted in excess tax benefits of $6 million which reduced our current provision for income taxes in our results of operations. The statutory tax withholding classification, which are cash payments made to taxing authorities for shares withheld, were applied retrospectively and reclassified the statutory tax withholding requirements in the statement of cash flows from Other liabilities in operating activities to Other in financing activities. This statutory tax withholding reclassification resulted in $11 million and $8 million being included in financing activities for the three months ended March 31, 2017 and 2016, respectively. There were no cumulative effect adjustments upon adoption of this ASU. Pending Accounting Updates ASU 2014-09 Revenue from Contracts with Customers In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers . ASU 2014-09 requires an entity to recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods and services. Insurance contracts do not fall within the scope of this ASU. The effective date of ASU 2014-09 is for interim and annual reporting periods beginning after December 15, 2017. The ASU has not yet been adopted and will not have a material impact on our company’s financial position, cash flows or results of operations. ASU 2016-01, Financial Instruments - Overall (Subtopic 825-10) - Recognition and Measurement of Financial Assets and Financial Liabilities In January 2016, the FASB issued ASU 2016-01, Financial Instruments - Overall (Subtopic 825-10) - Recognition and Measurement of Financial Assets and Financial Liabilities. ASU 2016-01 revises the accounting related to the classification and measurement of investments in equity securities and the presentation of certain fair value changes for financial liabilities measured at fair value. The effective date of ASU 2016-01 is for interim and annual reporting periods beginning after December 15, 2017. The ASU has not yet been adopted. Our results of operations will be impacted as changes in fair value of equity securities will be reported in net income instead of reported in accumulated other comprehensive income. ASU 2016-02, Leases (Topic 842) In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842). The main provision of ASU 2016-02 requires the recognition of lease assets and lease liabilities by lessees for those leases classified as operating leases under previous GAAP. The effective date of ASU 2016-02 is for interim and annual reporting periods beginning after December 15, 2018. The ASU has not yet been adopted. Management is currently evaluating the impact on our company’s consolidated financial position, cash flows and results of operations. ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments In June 2016, the FASB issued ASU 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments . ASU 2016-13 amends 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 complexity of credit impairment models and result in a more timely recognition of expected credit losses. The effective date of ASU 2016-13 is for interim and annual reporting periods beginning after December 15, 2019. The ASU has not yet been adopted. Management is currently evaluating the impact on our company's consolidated financial position, cash flows or results of operations. ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments . ASU 2016-15 addresses eight specific cash flow issues with the objective of reducing the existing diversity in practice. The effective date of ASU 2016-15 is for interim and annual reporting periods beginning after December 15, 2017. The ASU has not yet been adopted; however, it is not expected to have a material impact on our company's consolidated financial position, cash flows or results of operations. ASU 2017-07, Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost In March 2017, the FASB issued ASU 2017-07, Compensation - Retirement Benefits (Topic 715): Improving the Presentation of Net Periodic Postretirement Benefit Costs . ASU 2017-07 provides guidance on how to present the components of net periodic benefit costs in the income statement for pension plans and other post-retirement benefit plans. The effective date of ASU 2017-07 is for interim and annual reporting periods beginning after December 15, 2017. The ASU has not yet been adopted; however, it is not expected to have a material impact on our company's consolidated financial position, cash flows or results of operations. ASU 2017-08, Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities In March 2017, the FASB issued ASU 2017-08, Receivables - Nonrefundable Fees and Other Costs (Subtopic 310-20): Premium Amortization on Purchased Callable Debt Securities. ASU 2017-08 amends guidance on the amortization period of premiums on certain purchased callable debt securities. The amendments shorten the amortization period of premiums on certain purchased callable debt securities to the earliest call date. The amendments should be applied on a modified retrospective basis through a cumulative-effect adjustment to beginning retained earnings. The effective date of ASU 2017-08 is for interim and annual reporting periods beginning after December 15, 2018. The ASU has not yet been adopted. Management is currently evaluating the impact on our company's consolidated financial position, cash flows or results of operations.

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2017
Investments [Abstract]
Analysis Of Cost Or Amortized Cost, Gross Unrealized Gains And Losses And Fair Value for Investments	The following table provides cost or amortized cost, gross unrealized gains, gross unrealized losses and fair value for our fixed-maturity and equity securities: (Dollars in millions) Cost or amortized cost Gross unrealized Fair value At March 31, 2017 gains losses Fixed maturity securities: Corporate $ 5,570 $ 262 $ 17 $ 5,815 States, municipalities and political subdivisions 3,879 110 37 3,952 Commercial mortgage-backed 282 6 1 287 Government-sponsored enterprises 219 — 3 216 United States government 16 — — 16 Foreign government 10 — — 10 Convertibles and bonds with warrants attached 5 — — 5 Subtotal 9,981 378 58 10,301 Equity securities: Common equities 3,051 2,411 9 5,453 Nonredeemable preferred equities 189 34 — 223 Subtotal 3,240 2,445 9 5,676 Total $ 13,221 $ 2,823 $ 67 $ 15,977 At December 31, 2016 Fixed maturity securities: Corporate $ 5,555 $ 252 $ 26 $ 5,781 States, municipalities and political subdivisions 3,770 100 42 3,828 Commercial mortgage-backed 282 7 2 287 Government-sponsored enterprises 167 — 3 164 United States government 10 — — 10 Foreign government 10 — — 10 Convertibles and bonds with warrants attached 5 — — 5 Subtotal 9,799 359 73 10,085 Equity securities: Common equities 2,812 2,320 9 5,123 Nonredeemable preferred equities 183 28 — 211 Subtotal 2,995 2,348 9 5,334 Total $ 12,794 $ 2,707 $ 82 $ 15,419
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 gross 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 Fair value Unrealized losses Fair value Unrealized losses Fair value Unrealized losses At March 31, 2017 Fixed maturity securities: Corporate $ 381 $ 10 $ 136 $ 7 $ 517 $ 17 States, municipalities and political subdivisions 883 37 — — 883 37 Commercial mortgage-backed securities 75 1 2 — 77 1 Government-sponsored enterprises 165 3 — — 165 3 United States government 6 — — — 6 — Subtotal 1,510 51 138 7 1,648 58 Equity securities: Common equities 236 9 4 — 240 9 Subtotal 236 9 4 — 240 9 Total $ 1,746 $ 60 $ 142 $ 7 $ 1,888 $ 67 At December 31, 2016 Fixed maturity securities: Corporate $ 733 $ 15 $ 189 $ 11 $ 922 $ 26 States, municipalities and political subdivisions 989 42 — — 989 42 Commercial mortgage-backed 89 2 2 — 91 2 Government-sponsored enterprises 155 3 — — 155 3 United States government 6 — — — 6 — Subtotal 1,972 62 191 11 2,163 73 Equity securities: Common equities 103 9 — — 103 9 Nonredeemable preferred equities 4 — — — 4 — Subtotal 107 9 — — 107 9 Total $ 2,079 $ 71 $ 191 $ 11 $ 2,270 $ 82
Investments Classified by Contractual Maturity Date [Table Text Block]	Contractual maturity dates for fixed-maturity investments were: (Dollars in millions) Amortized cost Fair value % of fair value At March 31, 2017 Maturity dates: Due in one year or less $ 655 $ 669 6.5 % Due after one year through five years 2,764 2,911 28.3 Due after five years through ten years 3,862 3,981 38.6 Due after ten years 2,700 2,740 26.6 Total $ 9,981 $ 10,301 100.0 %
Investment Income, Realized Investment Gains And Losses And Change In Unrealized Investment Gains And Losses	The following table provides investment income, realized investment gains and losses, the change in unrealized investment gains and losses: (Dollars in millions) Three months ended March 31, 2017 2016 Investment income: Interest $ 111 $ 109 Dividends 39 37 Other 1 1 Total 151 147 Less investment expenses 2 2 Total $ 149 $ 145 Realized investment gains and losses: Fixed maturities: Gross realized gains $ 10 $ 3 Gross realized losses — (1 ) Other-than-temporary impairments — (2 ) Equity securities: Gross realized gains 153 62 Gross realized losses (4 ) (1 ) Other-than-temporary impairments — — Other 1 — Total $ 160 $ 61 Change in unrealized investment gains and losses: Fixed maturities $ 34 $ 116 Equity securities 97 174 Income tax (provision) benefit (46 ) (100 ) Total $ 85 $ 190

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
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 March 31, 2017 , and December 31, 2016 . We do not have any material liabilities carried at fair value. There were no transfers between Level 1 and Level 2. (Dollars in millions) Quoted prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) Total At March 31, 2017 Fixed maturities, available for sale: Corporate $ — $ 5,814 $ 1 $ 5,815 States, municipalities and political subdivisions — 3,952 — 3,952 Commercial mortgage-backed — 287 — 287 Government-sponsored enterprises — 216 — 216 United States government 16 — — 16 Foreign government — 10 — 10 Convertibles and bonds with warrants attached — 5 — 5 Subtotal 16 10,284 1 10,301 Common equities, available for sale 5,453 — — 5,453 Nonredeemable preferred equities, available for sale — 223 — 223 Separate accounts taxable fixed maturities — 764 — 764 Top Hat savings plan mutual funds and common 27 — — 27 Total $ 5,496 $ 11,271 $ 1 $ 16,768 At December 31, 2016 Fixed maturities, available for sale: Corporate $ — $ 5,703 $ 78 $ 5,781 States, municipalities and political subdivisions — 3,828 — 3,828 Commercial mortgage-backed — 287 — 287 Government-sponsored enterprises — 164 — 164 United States government 10 — — 10 Foreign government — 10 — 10 Convertibles and bonds with warrants attached — 5 — 5 Subtotal 10 9,997 78 10,085 Common equities, available for sale 5,123 — — 5,123 Nonredeemable preferred equities, available for sale — 211 — 211 Separate accounts taxable fixed maturities — 750 — 750 Top Hat savings plan mutual funds and common equity (included in Other assets) 24 — — 24 Total $ 5,157 $ 10,958 $ 78 $ 16,193
Asset Fair Value Measurements Using Significant Unobservable Inputs (Level 3)	The following table provides the change in Level 3 assets for the three months ended March 31 : (Dollars in millions) Asset fair value measurements using significant unobservable inputs Corporate fixed maturities Taxable fixed maturities - separate accounts Nonredeemable preferred equities Total Beginning balance, January 1, 2017 $ 78 $ — $ — $ 78 Total gains or losses (realized/unrealized): Included in net income — — — — Included in other comprehensive income — — — — Purchases — — — — Sales — — — — Transfers into Level 3 — — — — Transfers out of Level 3 (77 ) — — (77 ) Ending balance, March 31, 2017 $ 1 $ — $ — $ 1 Beginning balance, January 1, 2016 $ 51 $ 1 $ 3 $ 55 Total gains or losses (realized/unrealized): Included in net income — — — — Included in other comprehensive income — — (1 ) (1 ) Purchases 5 — — 5 Sales — — — — Transfers into Level 3 — — — — Transfers out of Level 3 (5 ) — — (5 ) Ending balance, March 31, 2016 $ 51 $ 1 $ 2 $ 54
Schedule of Carrying Values and Estimated Fair Values of Debt Instruments [Table Text Block]	This table summarizes the book value and principal amounts of our long-term debt: (Dollars in millions) Book value Principal amount Interest rate Year of issue March 31, December 31, March 31, December 31, 2017 2016 2017 2016 6.900 % 1998 Senior debentures, due 2028 $ 26 $ 26 $ 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 $ 787 $ 787 $ 793 $ 793
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 active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) Total At March 31, 2017 Life policy loans $ — $ — $ 40 $ 40 At December 31, 2016 Life policy loans $ — $ — $ 40 $ 40
Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
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 active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) Total At March 31, 2017 Note payable $ — $ 17 $ — $ 17 6.900% senior debentures, due 2028 — 33 — 33 6.920% senior debentures, due 2028 — 497 — 497 6.125% senior notes, due 2034 — 450 — 450 Total $ — $ 997 $ — $ 997 At December 31, 2016 Note payable $ — $ 20 $ — $ 20 6.900% senior debentures, due 2028 — 33 — 33 6.920% senior debentures, due 2028 — 488 — 488 6.125% senior notes, due 2034 — 435 — 435 Total $ — $ 976 $ — $ 976
Deferred Annuities, Structured Settlements, And Other
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair Values of Deferred Annuities, Structured Settlements and Other Items	The following table shows fair values of our deferred annuities and structured settlements included in life policy and investment contract reserves: (Dollars in millions) Quoted prices in active markets for identical assets (Level 1) Significant other observable inputs (Level 2) Significant unobservable inputs (Level 3) Total At March 31, 2017 Deferred annuities $ — $ — $ 844 $ 844 Structured settlements — 203 — 203 Total $ — $ 203 $ 844 $ 1,047 At December 31, 2016 Deferred annuities $ — $ — $ 839 $ 839 Structured settlements — 206 — 206 Total $ — $ 206 $ 839 $ 1,045

Property Casualty Loss and Lo25

Property Casualty Loss and Loss Expenses (Tables)	3 Months Ended
	Mar. 31, 2017
Premiums Written, Net [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) Three months ended March 31, 2017 2016 Gross loss and loss expense reserves, beginning of period $ 5,035 $ 4,660 Less reinsurance recoverable 298 281 Net loss and loss expense reserves, beginning of period 4,737 4,379 Net incurred loss and loss expenses related to: Current accident year 826 723 Prior accident years (38 ) (62 ) Total incurred 788 661 Net paid loss and loss expenses related to: Current accident year 185 146 Prior accident years 509 416 Total paid 694 562 Net loss and loss expense reserves, end of period 4,831 4,478 Plus reinsurance recoverable 297 272 Gross loss and loss expense reserves, end of period $ 5,128 $ 4,750

Life Policy and Investment Co26

Life Policy and Investment Contract Reserves (Tables)	3 Months Ended
	Mar. 31, 2017
Liability for Future Policy Benefits [Abstract]
Reserve For Losses Loss Adjustment Expenses Table [Text Block]	This table summarizes our life policy and investment contract reserves: (Dollars in millions) March 31, December 31, 2016 Life policy reserves: Ordinary/traditional life $ 1,026 $ 1,011 Other 45 45 Subtotal 1,071 1,056 Investment contract reserves: Deferred annuities 858 861 Universal life 588 578 Structured settlements 166 170 Other 6 6 Subtotal 1,618 1,615 Total life policy and investment contract reserves $ 2,689 $ 2,671

Deferred Acquisition Costs (Ta

Deferred Acquisition Costs (Tables)	3 Months Ended
	Mar. 31, 2017
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) Three months ended March 31, 2017 2016 Property casualty: Deferred policy acquisition costs asset, beginning of period $ 408 $ 388 Capitalized deferred policy acquisition costs 226 210 Amortized deferred policy acquisition costs (206 ) (201 ) Deferred policy acquisition costs asset, end of period $ 428 $ 397 Life: Deferred policy acquisition costs asset, beginning of period $ 229 $ 228 Capitalized deferred policy acquisition costs 13 12 Amortized deferred policy acquisition costs (8 ) (11 ) Amortized shadow deferred policy acquisition costs (2 ) (8 ) Deferred policy acquisition costs asset, end of period $ 232 $ 221 Consolidated: Deferred policy acquisition costs asset, beginning of period $ 637 $ 616 Capitalized deferred policy acquisition costs 239 222 Amortized deferred policy acquisition costs (214 ) (212 ) Amortized shadow deferred policy acquisition costs (2 ) (8 ) Deferred policy acquisition costs asset, end of period $ 660 $ 618

Accumulated Other Comprehensi28

Accumulated Other Comprehensive Income (Tables)	3 Months Ended
	Mar. 31, 2017
Accumulated Other Comprehensive Income [Abstract]
Schedule of Accumulated Other Comprehensive Income (Loss)	(Dollars in millions) Three months ended March 31, 2017 2016 Before tax Income tax Net Before tax Income tax Net Investments: AOCI, beginning of period $ 2,625 $ 908 $ 1,717 $ 2,094 $ 722 $ 1,372 OCI before realized gains recognized in net income 290 102 188 351 121 230 Realized gains recognized in net income (159 ) (56 ) (103 ) (61 ) (21 ) (40 ) OCI 131 46 85 290 100 190 AOCI, end of period $ 2,756 $ 954 $ 1,802 $ 2,384 $ 822 $ 1,562 Pension obligations: AOCI, beginning of period $ (26 ) $ (8 ) $ (18 ) $ (42 ) $ (14 ) $ (28 ) OCI excluding amortization recognized in net income — — — — — — Amortization recognized in net income 1 — 1 1 1 — OCI 1 — 1 1 1 — AOCI, end of period $ (25 ) $ (8 ) $ (17 ) $ (41 ) $ (13 ) $ (28 ) Life deferred acquisition costs, life policy reserves and other: AOCI, beginning of period $ (9 ) $ (3 ) $ (6 ) $ 1 $ 1 $ — OCI before realized gains recognized in net income 3 2 1 (4 ) (1 ) (3 ) Realized gains recognized in net income (1 ) (1 ) — — — — OCI 2 1 1 (4 ) (1 ) (3 ) AOCI, end of period $ (7 ) $ (2 ) $ (5 ) $ (3 ) $ — $ (3 ) Summary of AOCI: AOCI, beginning of period $ 2,590 $ 897 $ 1,693 $ 2,053 $ 709 $ 1,344 Investments OCI 131 46 85 290 100 190 Pension obligations OCI 1 — 1 1 1 — Life deferred acquisition costs, life policy reserves and other OCI 2 1 1 (4 ) (1 ) (3 ) Total OCI 134 47 87 287 100 187 AOCI, end of period $ 2,724 $ 944 $ 1,780 $ 2,340 $ 809 $ 1,531

Reinsurance (Tables)

Reinsurance (Tables)	3 Months Ended
	Mar. 31, 2017
Reinsurance Disclosures [Abstract]
Property Casualty Insurance Premiums Written On Assumed And Ceded Business	The table below includes our net written consolidated property casualty insurance premiums on assumed and ceded business: (Dollars in millions) Three months ended March 31, 2017 2016 Direct written premiums $ 1,226 $ 1,161 Assumed written premiums 33 21 Ceded written premiums (28 ) (35 ) Net written premiums $ 1,231 $ 1,147
Earned Consolidated Property Casualty Insurance Premiums On Assumed And Ceded Business	Our condensed consolidated statements of income include earned consolidated property casualty insurance premiums on assumed and ceded business: (Dollars in millions) Three months ended March 31, 2017 2016 Direct earned premiums $ 1,163 $ 1,119 Assumed earned premiums 27 15 Ceded earned premiums (39 ) (38 ) Earned premiums $ 1,151 $ 1,096
Incurred Consolidated Property Casualty Insurance Loss And Loss Expenses On Assumed And Ceded Business	Our condensed consolidated statements of income include incurred consolidated property casualty insurance loss and loss expenses on assumed and ceded business: (Dollars in millions) Three months ended March 31, 2017 2016 Direct incurred loss and loss expenses $ 788 $ 648 Assumed incurred loss and loss expenses 15 10 Ceded incurred loss and loss expenses (15 ) 3 Incurred loss and loss expenses $ 788 $ 661
Earned Life Insurance Premiums On Ceded Business	Our condensed consolidated statements of income include earned life insurance premiums on ceded business: (Dollars in millions) Three months ended March 31, 2017 2016 Direct earned premiums $ 74 $ 71 Ceded earned premiums (17 ) (13 ) Earned premiums $ 57 $ 58
Life Insurance Contract Holders' Benefits Incurred On Ceded Business	Our condensed consolidated statements of income include life insurance contract holders' benefits incurred on ceded business: (Dollars in millions) Three months ended March 31, 2017 2016 Direct contract holders' benefits incurred $ 76 $ 76 Ceded contract holders' benefits incurred (11 ) (13 ) Contract holders' benefits incurred $ 65 $ 63

Income Taxes (Tables)

Income Taxes (Tables)	3 Months Ended
	Mar. 31, 2017
Income Tax Disclosure [Abstract]
Differences Between The 35 Percent Statutory Income Tax Rate And Effective Income Tax Rate	The differences between the 35 percent statutory federal income tax rate and our effective income tax rate were as follows: (Dollars in millions) Three months ended March 31, 2017 2016 Tax at statutory rate: $ 97 35.0 % $ 93 35.0 % Increase (decrease) resulting from: Tax-exempt income from municipal bonds (9 ) (3.3 ) (9 ) (3.4 ) Dividend received exclusion (8 ) (2.9 ) (8 ) (3.0 ) Other (5 ) (1.6 ) 1 0.5 Provision for income taxes $ 75 27.2 % $ 77 29.1 %

Net Income Per Common Share (Ta

Net Income Per Common Share (Tables)	3 Months Ended
	Mar. 31, 2017
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) Three months ended March 31, 2017 2016 Numerator: Net income—basic and diluted $ 201 $ 188 Denominator: Basic weighted-average common shares outstanding 164.6 164.2 Effect of share-based awards: Stock options 1.1 1.0 Nonvested shares 0.8 0.8 Diluted weighted-average shares 166.5 166.0 Earnings per share: Basic $ 1.22 $ 1.14 Diluted 1.21 1.13 Number of anti-dilutive share-based awards 0.7 0.4

Employee Retirement Benefits (T

Employee Retirement Benefits (Tables)	3 Months Ended
	Mar. 31, 2017
Compensation and Retirement Disclosure [Abstract]
Schedule of Defined Benefit Plans Disclosures	The following summarizes the components of net periodic benefit cost for our qualified and supplemental pension plans: (Dollars in millions) Three months ended March 31, 2017 2016 Service cost $ 3 $ 3 Interest cost 3 3 Expected return on plan assets (5 ) (5 ) Amortization of actuarial loss and prior service cost 1 1 Net periodic benefit cost $ 2 $ 2

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2017
Segment Reporting [Abstract]
Segment Information	Segment information is summarized in the following table: (Dollars in millions) Three months ended March 31, 2017 2016 Revenues: Commercial lines insurance Commercial casualty $ 265 $ 257 Commercial property 223 214 Commercial auto 155 144 Workers' compensation 84 89 Other commercial 54 56 Commercial lines insurance premiums 781 760 Fee revenues 1 1 Total commercial lines insurance 782 761 Personal lines insurance Personal auto 141 131 Homeowner 125 119 Other personal 34 33 Personal lines insurance premiums 300 283 Fee revenues 2 1 Total personal lines insurance 302 284 Excess and surplus lines insurance 48 43 Life insurance premiums 57 58 Fee revenues 2 1 Total life insurance 59 59 Investments Investment income, net of expenses 149 145 Realized investment gains, net 160 61 Total investment revenue 309 206 Other Cincinnati Re insurance premiums 22 10 Other 1 1 Total other revenues 23 11 Total revenues $ 1,523 $ 1,364 Income (loss) before income taxes: Insurance underwriting results Commercial lines insurance $ (2 ) $ 50 Personal lines insurance (15 ) 28 Excess and surplus lines insurance 18 17 Life insurance — (1 ) Investments 286 184 Other (11 ) (13 ) Total income before income taxes $ 276 $ 265 Identifiable assets: March 31, December 31, 2016 Property casualty insurance $ 2,886 $ 2,967 Life insurance 1,359 1,366 Investments 16,123 15,569 Other 385 484 Total $ 20,753 $ 20,386

Accounting Policies (Details)

Accounting Policies (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification included in financing activities	$ (124)	$ (88)
Excess tax benefit	6
Accounting Standards Update 2016-09, Excess Tax Benefit Component [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification included in financing activities	11	$ 8
Cumulative effect adjustment	$ 0

Investments - Analysis of Cost

Investments - Analysis of Cost or Amortized Cost, Gross Unrealized Gains and Losses and Fair Value for Investments (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	$ 9,981	$ 9,799
Gross Unrealized Gains	378	359
Gross Unrealized Losses	58	73
Fair Value	10,301	10,085
Debt Securities | Corporate
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	5,570	5,555
Gross Unrealized Gains	262	252
Gross Unrealized Losses	17	26
Fair Value	5,815	5,781
Debt Securities | States, municipalities and political subdivisions
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	3,879	3,770
Gross Unrealized Gains	110	100
Gross Unrealized Losses	37	42
Fair Value	3,952	3,828
Debt Securities | Commercial mortgage-backed
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	282	282
Gross Unrealized Gains	6	7
Gross Unrealized Losses	1	2
Fair Value	287	287
Debt Securities | Government-sponsored enterprises
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	219	167
Gross Unrealized Gains	0	0
Gross Unrealized Losses	3	3
Fair Value	216	164
Debt Securities | United States government
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	16	10
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	16	10
Debt Securities | Foreign government
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	10	10
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	10	10
Debt Securities | Convertibles and bonds with warrants attached
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	5	5
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Fair Value	5	5
Equity Securities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	3,240	2,995
Gross Unrealized Gains	2,445	2,348
Gross Unrealized Losses	9	9
Fair Value	5,676	5,334
Equity Securities | Common equities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	3,051	2,812
Gross Unrealized Gains	2,411	2,320
Gross Unrealized Losses	9	9
Fair Value	5,453	5,123
Equity Securities | Nonredeemable preferred equities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	189	183
Gross Unrealized Gains	34	28
Gross Unrealized Losses	0	0
Fair Value	223	211
Fixed Maturities And Equity Securities
Schedule of Available-for-sale Securities [Line Items]
Cost or Amortized Cost	13,221	12,794
Gross Unrealized Gains	2,823	2,707
Gross Unrealized Losses	67	82
Fair Value	$ 15,977	$ 15,419

Investments - Fair Values and U

Investments - Fair Values and Unrealized Losses by Investment Category and by Duration of Securities' Continuous Unrealized Loss Position (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	$ 1,746	$ 2,079
Less than 12 months Unrealized Losses	60	71
12 months or more Fair Value	142	191
12 months or more Unrealized Losses	7	11
Total Fair Value	1,888	2,270
Total Unrealized Losses	67	82
Fixed Maturities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	1,510	1,972
Less than 12 months Unrealized Losses	51	62
12 months or more Fair Value	138	191
12 months or more Unrealized Losses	7	11
Total Fair Value	1,648	2,163
Total Unrealized Losses	58	73
Fixed Maturities | Corporate
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	381	733
Less than 12 months Unrealized Losses	10	15
12 months or more Fair Value	136	189
12 months or more Unrealized Losses	7	11
Total Fair Value	517	922
Total Unrealized Losses	17	26
Fixed Maturities | States, municipalities and political subdivisions
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	883	989
Less than 12 months Unrealized Losses	37	42
12 months or more Fair Value	0	0
12 months or more Unrealized Losses	0	0
Total Fair Value	883	989
Total Unrealized Losses	37	42
Fixed Maturities | Commercial mortgage-backed
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	75	89
Less than 12 months Unrealized Losses	1	2
12 months or more Fair Value	2	2
12 months or more Unrealized Losses	0	0
Total Fair Value	77	91
Total Unrealized Losses	1	2
Fixed Maturities | Government-sponsored enterprises
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	165	155
Less than 12 months Unrealized Losses	3	3
12 months or more Fair Value	0	0
12 months or more Unrealized Losses	0	0
Total Fair Value	165	155
Total Unrealized Losses	3	3
Fixed Maturities | United States government
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	6	6
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	6	6
Total Unrealized Losses	0	0
Equity Securities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	236	107
Less than 12 months Unrealized Losses	9	9
12 months or more Fair Value	4	0
12 months or more Unrealized Losses	0	0
Total Fair Value	240	107
Total Unrealized Losses	9	9
Equity Securities | Common equities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value	236	103
Less than 12 months Unrealized Losses	9	9
12 months or more Fair Value	4	0
12 months or more Unrealized Losses	0	0
Total Fair Value	240	103
Total Unrealized Losses	$ 9	9
Equity Securities | Nonredeemable preferred equities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Fair Value		4
Less than 12 months Unrealized Losses		0
12 months or more Fair Value		0
12 months or more Unrealized Losses		0
Total Fair Value		4
Total Unrealized Losses		$ 0

Investments - Schedule of Contr

Investments - Schedule of Contractual Maturities of Investments (Details) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Amortized cost
Due in one year or less	$ 655
Due after one year through five years	2,764
Due after five years through ten years	3,862
Due after ten years	2,700
Total	9,981	$ 9,799
Fair value
Due in one year or less	669
Due after one year through five years	2,911
Due after five years through ten years	3,981
Due after ten years	2,740
Total	$ 10,301	$ 10,085
% of fair value
Due in one year or less	6.50%
Due after one year through five years	28.30%
Due after five years through ten years	38.60%
Due after ten years	26.60%
Total	100.00%

Investments - Realized Investme

Investments - Realized Investment Gains and Losses and Change in Unrealized Investment Gains and Losses and Other Items (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Investment income summary:
Interest	$ 111	$ 109
Dividends	39	37
Other	1	1
Total	151	147
Less investment expenses	2	2
Total	149	145
Realized investment gains and losses summary:
Realized investment gains, net	160	61
Change in unrealized gains and losses summary:
Fixed maturities	85	190
Income tax (provision) benefit	(46)	(100)
Fixed Maturities
Realized investment gains and losses summary:
Gross realized gains	10	3
Gross realized losses	0	(1)
Other-than-temporary impairments	0	(2)
Change in unrealized gains and losses summary:
Fixed maturities	34	116
Equity Securities
Realized investment gains and losses summary:
Gross realized gains	153	62
Gross realized losses	(4)	(1)
Other-than-temporary impairments	0	0
Other	1	0
Change in unrealized gains and losses summary:
Fixed maturities	$ 97	$ 174

Investments - Additional Inform

Investments - Additional Information (Detail)	3 Months Ended		12 Months Ended
	Mar. 31, 2017USD ($)security	Mar. 31, 2016security	Dec. 31, 2016USD ($)security
Gain (Loss) on Investments [Line Items]
Largest Single Common Stock Holding	$ 201,000,000
Largest equity holdings to total equity portfolio	3.70%
Largest equity holdings to total portfolio	1.30%
Unrealized losses 12 months or more (equity investment less than $500,000)	$ (7,000,000)		$ (11,000,000)
Fixed maturity investments, Percentage of amortized costs	70.00%		70.00%
Fixed Maturities
Gain (Loss) on Investments [Line Items]
Unrealized investment gains due to a net gain position	$ 378,000,000		$ 359,000,000
Number Of Securities Other Than Temporary Impairment Losses1 | security	0	2
Provision for Other Credit Losses	$ 0
Number Of Securities Continuous Unrealized Loss Position More Than Twelve Months | security	22		32
Unrealized losses 12 months or more (equity investment less than $500,000)	$ (7,000,000)		$ (11,000,000)
Number Of Securities Continuous Unrealized Loss Position More Than Twelve Months and Below 70 Percent of Amortized Cost	0		0
Equity Securities
Gain (Loss) on Investments [Line Items]
Unrealized investment gains due to a net gain position	$ 2,445,000,000		$ 2,348,000,000
Number Of Securities Other Than Temporary Impairment Losses1 | security	0	0
Number Of Securities Continuous Unrealized Loss Position More Than Twelve Months	1		0
Unrealized losses 12 months or more (equity investment less than $500,000)	$ 0		$ 0
Number Of Securities Continuous Unrealized Loss Position More Than Twelve Months and Below 70 Percent of Amortized Cost	0
Largest unrealized investment gains in common stock portfolio [Member]
Gain (Loss) on Investments [Line Items]
Unrealized investment gains due to a net gain position	$ 760,000,000
Common equities
Gain (Loss) on Investments [Line Items]
Number of securities	7

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Hierarchy for Assets Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	$ 10,301	$ 10,085
Equity securities, at fair value	5,676	5,334
Separate accounts	775	766
Top Hat savings plan mutual funds and common equity (included in Other assets)	27	24
Fair value of asset	16,768	16,193
Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	10,301	10,085
Debt Securities | Corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	5,815	5,781
Debt Securities | States, municipalities and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	3,952	3,828
Debt Securities | Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	287	287
Debt Securities | Government-sponsored enterprises
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	216	164
Debt Securities | United States government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	16	10
Debt Securities | Foreign government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	10	10
Debt Securities | Convertibles and bonds with warrants attached
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	5	5
Equity Securities | Common equities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, at fair value	5,453	5,123
Equity Securities | Nonredeemable preferred equities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, at fair value	223	211
Taxable Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Separate accounts	764	750
Quoted prices in active markets for identical assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Top Hat savings plan mutual funds and common equity (included in Other assets)	27	24
Fair value of asset	5,496	5,157
Quoted prices in active markets for identical assets (Level 1) | Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	16	10
Quoted prices in active markets for identical assets (Level 1) | Debt Securities | Corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Quoted prices in active markets for identical assets (Level 1) | Debt Securities | States, municipalities and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Quoted prices in active markets for identical assets (Level 1) | Debt Securities | Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Quoted prices in active markets for identical assets (Level 1) | Debt Securities | Government-sponsored enterprises
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Quoted prices in active markets for identical assets (Level 1) | Debt Securities | United States government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	16	10
Quoted prices in active markets for identical assets (Level 1) | Debt Securities | Foreign government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Quoted prices in active markets for identical assets (Level 1) | Debt Securities | Convertibles and bonds with warrants attached
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Quoted prices in active markets for identical assets (Level 1) | Equity Securities | Common equities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, at fair value	5,453	5,123
Quoted prices in active markets for identical assets (Level 1) | Equity Securities | Nonredeemable preferred equities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, at fair value	0	0
Quoted prices in active markets for identical assets (Level 1) | Taxable Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Separate accounts	0	0
Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Top Hat savings plan mutual funds and common equity (included in Other assets)	0	0
Fair value of asset	11,271	10,958
Significant other observable inputs (Level 2) | Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	10,284	9,997
Significant other observable inputs (Level 2) | Debt Securities | Corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	5,814	5,703
Significant other observable inputs (Level 2) | Debt Securities | States, municipalities and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	3,952	3,828
Significant other observable inputs (Level 2) | Debt Securities | Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	287	287
Significant other observable inputs (Level 2) | Debt Securities | Government-sponsored enterprises
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	216	164
Significant other observable inputs (Level 2) | Debt Securities | United States government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Significant other observable inputs (Level 2) | Debt Securities | Foreign government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	10	10
Significant other observable inputs (Level 2) | Debt Securities | Convertibles and bonds with warrants attached
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	5	5
Significant other observable inputs (Level 2) | Equity Securities | Common equities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, at fair value	0	0
Significant other observable inputs (Level 2) | Equity Securities | Nonredeemable preferred equities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, at fair value	223	211
Significant other observable inputs (Level 2) | Taxable Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Separate accounts	764	750
Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Top Hat savings plan mutual funds and common equity (included in Other assets)	0	0
Fair value of asset	1	78
Significant unobservable inputs (Level 3) | Debt Securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	1	78
Significant unobservable inputs (Level 3) | Debt Securities | Corporate
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	1	78
Significant unobservable inputs (Level 3) | Debt Securities | States, municipalities and political subdivisions
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Significant unobservable inputs (Level 3) | Debt Securities | Commercial mortgage-backed
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Significant unobservable inputs (Level 3) | Debt Securities | Government-sponsored enterprises
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Significant unobservable inputs (Level 3) | Debt Securities | United States government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Significant unobservable inputs (Level 3) | Debt Securities | Foreign government
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Significant unobservable inputs (Level 3) | Debt Securities | Convertibles and bonds with warrants attached
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed maturities, at fair value	0	0
Significant unobservable inputs (Level 3) | Equity Securities | Common equities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, at fair value	0	0
Significant unobservable inputs (Level 3) | Equity Securities | Nonredeemable preferred equities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Equity securities, at fair value	0	0
Significant unobservable inputs (Level 3) | Taxable Fixed Maturities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Separate accounts	$ 0	$ 0

Fair Value Measurements - Chang

Fair Value Measurements - Change in Level 3 Assets (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 78	$ 55
Total gains or losses (realized/unrealized):
Included in net income	0	0
Included in other comprehensive income	0	(1)
Purchases	0	5
Sales	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	(77)	(5)
Ending balance	1	54
Corporate Fixed Maturities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	78	51
Total gains or losses (realized/unrealized):
Included in net income	0	0
Included in other comprehensive income	0	0
Purchases	0	5
Sales	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	(77)	(5)
Ending balance	1	51
Taxable Fixed Maturities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	0	1
Total gains or losses (realized/unrealized):
Included in net income	0	0
Included in other comprehensive income	0	0
Purchases	0	0
Sales	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Ending balance	0	1
Preferred Equities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	0	3
Total gains or losses (realized/unrealized):
Included in net income	0	0
Included in other comprehensive income	0	(1)
Purchases	0	0
Sales	0	0
Transfers into Level 3	0	0
Transfers out of Level 3	0	0
Ending balance	$ 0	$ 2

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Book Value and Principal Amounts of Long-Term Debt (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Book value	$ 787	$ 787
Principal amount of debt	$ 793	$ 793
Senior Debentures 6.900% Due 2028
Debt Instrument [Line Items]
Interest rate	6.90%	6.90%
Debt issuance year	1,998	1,998
Book value	$ 26	$ 26
Principal amount of debt	$ 28	$ 28
Senior Debentures 6.920% Due 2028
Debt Instrument [Line Items]
Interest rate	6.92%	6.92%
Debt issuance year	2,005	2,005
Book value	$ 391	$ 391
Principal amount of debt	$ 391	$ 391
Senior Notes 6.152% Due 2034
Debt Instrument [Line Items]
Interest rate	6.125%	6.125%
Debt issuance year	2,004	2,004
Book value	$ 370	$ 370
Principal amount of debt	$ 374	$ 374

Fair Value Measurements - Fai43

Fair Value Measurements - Fair Values of Note Payable and Long-Term Debt (Detail) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of note payable	$ 17	$ 20
Total	997	976
Finance receivable	$ 50	$ 51
Senior Debentures 6.900 % Due 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate	6.90%	6.90%
Debt instrument, year of maturity	2,028	2,028
Fair value of senior debt	$ 33	$ 33
Senior Debentures 6.920 % Due 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate	6.92%	6.92%
Debt instrument, year of maturity	2,028	2,028
Fair value of senior debt	$ 497	$ 488
Senior Notes 6.125 % Due 2034
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest rate	6.125%	6.125%
Debt instrument, year of maturity	2,034	2,034
Fair value of senior debt	$ 450	$ 435
Quoted prices in active markets for identical assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of note payable	0	0
Total	0	0
Quoted prices in active markets for identical assets (Level 1) | Senior Debentures 6.900 % Due 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of senior debt	0	0
Quoted prices in active markets for identical assets (Level 1) | Senior Debentures 6.920 % Due 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of senior debt	0	0
Quoted prices in active markets for identical assets (Level 1) | Senior Notes 6.125 % Due 2034
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of senior debt	0	0
Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of note payable	17	20
Total	997	976
Significant other observable inputs (Level 2) | Senior Debentures 6.900 % Due 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of senior debt	33	33
Significant other observable inputs (Level 2) | Senior Debentures 6.920 % Due 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of senior debt	497	488
Significant other observable inputs (Level 2) | Senior Notes 6.125 % Due 2034
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of senior debt	450	435
Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of note payable	0	0
Total	0	0
Significant unobservable inputs (Level 3) | Senior Debentures 6.900 % Due 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of senior debt	0	0
Significant unobservable inputs (Level 3) | Senior Debentures 6.920 % Due 2028
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of senior debt	0	0
Significant unobservable inputs (Level 3) | Senior Notes 6.125 % Due 2034
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of senior debt	0	0
Deferred Annuities And Structured Settlements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liability for Future Policy Benefits, Individual and Group Annuities and Supplementary Contracts	858	861
Policy Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivable	$ 30	$ 31

Fair Value Measurements - Fai44

Fair Value Measurements - Fair Value of Life Policy Loans (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivable	$ 50	$ 51
Fair value of life policy loans	40	40
Quoted prices in active markets for identical assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of life policy loans	0	0
Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of life policy loans	0	0
Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of life policy loans	40	40
Policy Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivable	$ 30	$ 31

Fair Value Measurements - Fai45

Fair Value Measurements - Fair Values of Deferred Annuities, Structured Settlements and Other Items (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	$ 1,047	$ 1,045
Deferred annuities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	844	839
Structured Settlements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	203	206
Quoted prices in active markets for identical assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	0	0
Quoted prices in active markets for identical assets (Level 1) | Deferred annuities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	0	0
Quoted prices in active markets for identical assets (Level 1) | Structured Settlements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	0	0
Significant other observable inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	203	206
Significant other observable inputs (Level 2) | Deferred annuities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	0	0
Significant other observable inputs (Level 2) | Structured Settlements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	203	206
Significant unobservable inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	844	839
Significant unobservable inputs (Level 3) | Deferred annuities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	844	839
Significant unobservable inputs (Level 3) | Structured Settlements
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value of life insurance liabilities	$ 0	$ 0

Fair Value Measurements - Addit

Fair Value Measurements - Additional Information (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivable	$ 50	$ 51
Loss and loss expense reserves	5,177	5,085
Life Policy Loans
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Finance receivable	30	31
Deferred Annuities And Structured Settlements [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liability for Future Policy Benefits, Individual and Group Annuities and Supplementary Contracts	858	861
Loss and loss expense reserves	$ 166	$ 170
Maximum
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Percentage Of Level 3 Assets To Total Financial Instruments Measured At Fair Value	1.00%

Property Casualty Loss and Lo47

Property Casualty Loss and Loss Expenses - Consolidated Property Casualty Loss and Loss Expense Reserves (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Summary of Consolidated Property Casualty Loss and Loss Expense Reserves [Roll Forward]
Gross loss and loss expense reserves, beginning of period	$ 5,035	$ 4,660
Less reinsurance recoverable	298	281
Net loss and loss expense reserves, beginning of period	4,737	4,379
Current accident year	826	723
Prior accident years	(38)	(62)
Total incurred	788	661
Current accident year	185	146
Prior accident years	509	416
Total paid	694	562
Net loss and loss expense reserves, end of period	4,831	4,478
Plus reinsurance recoverable	297	272
Gross loss and loss expense reserves, end of period	$ 5,128	$ 4,750

Property Casualty Loss and Lo48

Property Casualty Loss and Loss Expenses - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Reserve for loss and loss expenses	$ 5,128	$ 4,750	$ 5,035	$ 4,660
Prior accident years	(38)	(62)
Life and Health Loss Reserves
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Reserve for loss and loss expenses	49	54
Commercial Lines
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Prior accident years	(11)	(29)
Commercial Lines | Workers' Compensation
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Prior accident years	(18)	(13)
Commercial Lines | Commercial Casualty Segment [Member]
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Prior accident years	15
Commercial Lines | Other Commercial Lines [Member]
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Prior accident years	(8)	(13)
Commercial Lines | Commercial Auto
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Prior accident years	10	8
Commercial Lines | Commercial Property Segment [Member]
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Prior accident years	(10)	(8)
Personal Lines
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Prior accident years	(10)	(18)
Personal Lines | Homeowner [Member]
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Prior accident years		(8)
Excess and Surplus Lines Insurance
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Prior accident years	(13)	(14)
Reinsurance assumed and other non segment [Member]
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Prior accident years	(4)	(1)
Consolidated Property and Casualty Insurance Entity | Catastrophe Development
Supplemental Information for Property, Casualty Insurance Underwriters [Line Items]
Prior accident years	$ (11)	$ (7)

Reserves in Addition to Account

Reserves in Addition to Account Balance, Based on Expected No-Lapse Guarantee Benefits and Expected Policy Assessments (Detail) - USD ($) $ in Millions	Mar. 31, 2017	Dec. 31, 2016
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	$ 2,689	$ 2,671
Life policy reserves:
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	1,071	1,056
Life policy reserves: | Ordinary/traditional life
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	1,026	1,011
Life policy reserves: | Other
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	45	45
Investment contract reserves:
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	1,618	1,615
Investment contract reserves: | Deferred annuities
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	858	861
Investment contract reserves: | Universal life
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	588	578
Investment contract reserves: | Structured settlements
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	166	170
Investment contract reserves: | Other
Liability for Future Policy Benefit, by Product Segment [Line Items]
Life policy and investment contract reserves	$ 6	$ 6

Deferred Acquisition Costs - De

Deferred Acquisition Costs - Deferred Policy Acquisition Costs and Asset Reconciliation (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs asset, beginning of period	$ 637	$ 616
Capitalized deferred policy acquisition costs	239	222
Deferred Policy Acquisition Cost, Amortization Expense	(214)	(212)
Deferred Policy Acquisition Cost, Amortization Expense, Other	(2)	(8)
Deferred policy acquisition costs asset, end of period	660	618
Life Insurance Product Line [Member]
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs asset, beginning of period	229	228
Capitalized deferred policy acquisition costs	13	12
Deferred Policy Acquisition Cost, Amortization Expense	(8)	(11)
Deferred Policy Acquisition Cost, Amortization Expense, Other	(2)	(8)
Deferred policy acquisition costs asset, end of period	232	221
Consolidated Property and Casualty Insurance Entity
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Deferred policy acquisition costs asset, beginning of period	408	388
Capitalized deferred policy acquisition costs	226	210
Deferred Policy Acquisition Cost, Amortization Expense	(206)	(201)
Deferred policy acquisition costs asset, end of period	$ 428	$ 397

Accumulated Other Comprehensi51

Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	$ 1,780		$ 1,693
Accumulated other comprehensive income, net of tax, end of period	1,780
Accumulated Net Unrealized Investment Gain (Loss)
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before tax, beginning of period	2,625	$ 2,094
Other comprehensive income before reclassification, before tax	290	351
Reclassification adjustment, before tax	(159)	(61)
Effect on other comprehensive income, before tax	131	290
Accumulated other comprehensive income, before tax, end of period	2,756	2,384
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	908	722
Other comprehensive income before reclassification, tax	102	121
Reclassification adjustment, tax	(56)	(21)
Effect on other comprehensive income, tax	46	100
Accumulated other comprehensive income, tax, end of period	954	822
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	1,802	1,562	1,717	$ 1,372
Other comprehensive income before reclassification, net of tax	188	230
Reclassification adjustment, net of tax	(103)	(40)
Effect on other comprehensive income, net of tax	85	190
Accumulated other comprehensive income, net of tax, end of period	1,802	1,562
Accumulated Defined Benefit Plans Adjustment
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before tax, beginning of period	(26)	(42)
Other comprehensive income before reclassification, before tax	0	0
Reclassification adjustment, before tax	1	1
Effect on other comprehensive income, before tax	1	1
Accumulated other comprehensive income, before tax, end of period	(25)	(41)
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	(8)	(14)
Other comprehensive income before reclassification, tax	0	0
Reclassification adjustment, tax	0	1
Effect on other comprehensive income, tax	0	1
Accumulated other comprehensive income, tax, end of period	(8)	(13)
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	(17)	(28)	(18)	(28)
Other comprehensive income before reclassification, net of tax	0	0
Reclassification adjustment, net of tax	1	0
Effect on other comprehensive income, net of tax	1	0
Accumulated other comprehensive income, net of tax, end of period	(17)	(28)
Accumulated Net Unrealized Gain (Loss) on Deferred Costs, Reserves And Other
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before tax, beginning of period	(9)	1
Other comprehensive income before reclassification, before tax	3	(4)
Reclassification adjustment, before tax	(1)	0
Effect on other comprehensive income, before tax	2	(4)
Accumulated other comprehensive income, before tax, end of period	(7)	(3)
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	(3)	1
Other comprehensive income before reclassification, tax	2	(1)
Reclassification adjustment, tax	(1)	0
Effect on other comprehensive income, tax	1	(1)
Accumulated other comprehensive income, tax, end of period	(2)	0
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	(5)	(3)	(6)	0
Other comprehensive income before reclassification, net of tax	1	(3)
Reclassification adjustment, net of tax	0	0
Effect on other comprehensive income, net of tax	1	(3)
Accumulated other comprehensive income, net of tax, end of period	(5)	(3)
Accumulated Other Comprehensive Income (Loss)
Accumulated Other Comprehensive Income Loss Before Tax [Abstract]
Accumulated other comprehensive income, before tax, beginning of period	2,590	2,053
Change in unrealized gains, net, on investments available for sale, before tax	131	290
Change in pension obligations, before tax	1	1
Change in life deferred acquisition costs, life policy reserves and other, before tax	2	(4)
Effect on other comprehensive income, before tax	134	287
Accumulated other comprehensive income, before tax, end of period	2,724	2,340
Accumulated Other Comprehensive Income (Loss), Tax [Abstract]
Accumulated other comprehensive income, tax, beginning of period	897	709
Change in unrealized gains, net, on investments available for sale, tax	46	100
Change in pension obligations, tax	0	1
Change in life deferred acquisition costs, life policy reserves and other, tax	1	(1)
Effect on other comprehensive income, tax	47	100
Accumulated other comprehensive income, tax, end of period	944	809
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income, net of tax, beginning of period	1,780	1,531	$ 1,693	$ 1,344
Change in unrealized gains, net, on investments available for sale, net of tax	85	190
Change in pension obligations, net of tax	1	0
Change in life deferred acquisition costs, life policy reserves and other, net of tax	1	(3)
Effect on other comprehensive income, net of tax	87	187
Accumulated other comprehensive income, net of tax, end of period	$ 1,780	$ 1,531

Reinsurance - Written Consolida

Reinsurance - Written Consolidated Property Casualty Insurance Premium on Assumed and Ceded Business (Details) - Consolidated Property and Casualty Insurance Entity - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Property Casualty Insurance Premiums Written On Assumed And Ceded Business [Line Items]
Direct written premiums	$ 1,226	$ 1,161
Assumed written premiums	33	21
Ceded written premiums	(28)	(35)
Net written premiums	$ 1,231	$ 1,147

Reinsurance - Earned Consolidat

Reinsurance - Earned Consolidated Property Casualty Insurance Premiums on Assumed and Ceded Business (Detail) - Consolidated Property and Casualty Insurance Entity - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct earned premiums	$ 1,163	$ 1,119
Assumed earned premiums	27	15
Ceded earned premiums	(39)	(38)
Earned premiums	$ 1,151	$ 1,096

Reinsurance - Incurred Consolid

Reinsurance - Incurred Consolidated Property Casualty Insurance Loss and Loss Expenses on Assumed and Ceded Business (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Incurred loss and loss expenses	$ 853	$ 724
Consolidated Property and Casualty Insurance Entity
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct incurred loss and loss expenses	788	648
Assumed incurred loss and loss expenses	15	10
Ceded incurred loss and loss expenses	(15)	3
Incurred loss and loss expenses	$ 788	$ 661

Reinsurance - Earned Life Insur

Reinsurance - Earned Life Insurance Premiums on Ceded Business (Detail) - Life Insurance Segment - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct earned premiums	$ 74	$ 71
Ceded earned premiums	(17)	(13)
Earned premiums	$ 57	$ 58

Reinsurance - Life Insurance Co

Reinsurance - Life Insurance Contract Holders' Benefits Incurred on Ceded Business (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Insurance losses and contract holders' benefits	$ 853	$ 724
Life Insurance Segment
Reinsurance Premiums for Insurance Companies, by Product Segment [Line Items]
Direct contract holders' benefits incurred	76	76
Ceded contract holders' benefits incurred	(11)	(13)
Insurance losses and contract holders' benefits	$ 65	$ 63

Income Taxes - Differences Betw

Income Taxes - Differences Between 35 Percent Statutory Income Tax Rate and Effective Income Tax Rate (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Tax Disclosure [Abstract]
Tax at statutory rate	$ 97	$ 93
Increase (decrease) resulting from:
Tax-exempt income from municipal bonds	(9)	(9)
Dividend received exclusion	(8)	(8)
Other	(5)	1
Total provision for income taxes	$ 75	$ 77
Tax at statutory rate	35.00%	35.00%
Increase (decrease) resulting from:
Tax-exempt income from municipal bonds	(3.30%)	(3.40%)
Dividend received exclusion	(2.90%)	(3.00%)
Other	(1.60%)	0.50%
Provision for income taxes	27.20%	29.10%

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Income Tax Disclosure [Abstract]
Tax at statutory rate, percentage	35.00%	35.00%
Excess tax benefit, ASU 2016-09	$ 6
Effect of excess tax benefit, ASU 2016-09, percent	2.20%

Net Income Per Common Share - C

Net Income Per Common Share - Calculations for Basic and Diluted Earnings Per Share (Detail) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Numerator:
Net income-basic and diluted	$ 201	$ 188
Denominator:
Basic weighted-average common shares outstanding (in shares)	164.6	164.2
Diluted weighted-average shares	166.5	166
Earnings per share:
Basic (in USD per share)	$ 1.22	$ 1.14
Diluted (in USD per share)	$ 1.21	$ 1.13
Number of anti-dilutive stock-based awards (in shares)	0.7	0.4
Stock Options
Denominator:
Effect of stock-based awards (in shares)	1.1	1
Nonvested shares
Denominator:
Effect of stock-based awards (in shares)	0.8	0.8

Employee Retirement Benefits -

Employee Retirement Benefits - Components of Net Periodic Costs for Qualified and Supplemental Pension Plans (Detail) - Qualified Pension Plans [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 3	$ 3
Interest cost	3	3
Expected return on plan assets	(5)	(5)
Amortization of actuarial loss and prior service cost	1	1
Net periodic benefit cost	$ 2	$ 2

Employee Retirement Benefits 61

Employee Retirement Benefits - Defined Contribution Plan (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Matching contributions to 401(k) and Top Hat plans	$ 6	$ 4
Qualified Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Expected contributions by employer in the remainder of year	0
Pension contributions	$ 5

Segment Information (Detail)

Segment Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Earned premiums	$ 1,208	$ 1,154
Fee revenues	5	3
Investment income, net of expenses	149	145
Realized investment gains, net	160	61
Other	1	1
Total revenues	1,523	1,364
Income (loss) before income taxes	276	265
Identifiable assets	20,753		$ 20,386
Consolidated Property and Casualty Insurance Entity
Segment Reporting Information [Line Items]
Identifiable assets	2,886		2,967
Life Insurance Segment
Segment Reporting Information [Line Items]
Identifiable assets	1,359		1,366
Investments Segment
Segment Reporting Information [Line Items]
Identifiable assets	16,123		15,569
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Other	1	1
Total revenues	23	11
Income (loss) before income taxes	(11)	(13)
Identifiable assets	385		$ 484
Corporate, Non-Segment [Member] | Reinsurance assumed and other non segment [Member]
Segment Reporting Information [Line Items]
Earned premiums	22	10
Operating Segments | Commercial Lines
Segment Reporting Information [Line Items]
Earned premiums	781	760
Fee revenues	1	1
Total revenues	782	761
Income (loss) before income taxes	(2)	50
Operating Segments | Personal Lines
Segment Reporting Information [Line Items]
Earned premiums	300	283
Fee revenues	2	1
Total revenues	302	284
Income (loss) before income taxes	(15)	28
Operating Segments | Excess and Surplus Lines Insurance
Segment Reporting Information [Line Items]
Earned premiums	48	43
Income (loss) before income taxes	18	17
Operating Segments | Life Insurance Segment
Segment Reporting Information [Line Items]
Earned premiums	57	58
Fee revenues	2	1
Total revenues	59	59
Income (loss) before income taxes	0	(1)
Operating Segments | Investments Segment
Segment Reporting Information [Line Items]
Investment income, net of expenses	149	145
Realized investment gains, net	160	61
Total revenues	309	206
Income (loss) before income taxes	286	184
Commercial Casualty | Operating Segments | Commercial Lines
Segment Reporting Information [Line Items]
Earned premiums	265	257
Commercial Property | Operating Segments | Commercial Lines
Segment Reporting Information [Line Items]
Earned premiums	223	214
Commercial Auto | Operating Segments | Commercial Lines
Segment Reporting Information [Line Items]
Earned premiums	155	144
Workers' Compensation | Operating Segments | Commercial Lines
Segment Reporting Information [Line Items]
Earned premiums	84	89
Other Commercial Lines | Operating Segments | Commercial Lines
Segment Reporting Information [Line Items]
Earned premiums	54	56
Personal Auto | Operating Segments | Personal Lines
Segment Reporting Information [Line Items]
Earned premiums	141	131
Home Owner Segment | Operating Segments | Personal Lines
Segment Reporting Information [Line Items]
Earned premiums	125	119
Other Personal Lines | Operating Segments | Personal Lines
Segment Reporting Information [Line Items]
Earned premiums	$ 34	$ 33

Segment Information - Narrative

Segment Information - Narrative (Details)	3 Months Ended
	Mar. 31, 2017segmentindustry
Segment Reporting [Abstract]
Number of Industries Operating In | industry	2
Number of Reportable Segments | segment	5