The Travelers Companies, Inc. (TRV) 10-Q 24 Apr 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2018	Apr. 19, 2018
Document and Entity Information
Registrant name	Travelers Companies, Inc.
Central index key	86,312
Document type	10-Q
Document period end date	Mar. 31, 2018
Amendment flag	false
Current fiscal year end date	--12-31
Filer category	Large Accelerated Filer
Common stock shares outstanding		270,261,296
Document fiscal year focus	2,018
Document fiscal period focus	Q1

Consolidated Statement of Incom

Consolidated Statement of Income (Unaudited) - USD ($) shares in Millions, $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Revenues
Premiums		$ 6,537	$ 6,183
Net investment income		603	610
Fee income		103	113
Net realized investment gains (losses)	[1]	(11)	5
Other revenues		54	31
Total revenues		7,286	6,942
Claims and expenses
Claims and claim adjustment expenses		4,296	4,094
Amortization of deferred acquisition costs		1,061	1,003
General and administrative expenses		1,062	996
Interest expense		89	89
Total claims and expenses		6,508	6,182
Income before income taxes		778	760
Income tax expense		109	143
Net income		$ 669	$ 617
Net income per share
Basic (in dollars per share)		$ 2.45	$ 2.19
Diluted (in dollars per share)		$ 2.42	$ 2.17
Weighted average number of common shares outstanding
Basic (in shares)		271	279.7
Diluted (in shares)		273.9	282.4
Cash dividends declared per common share (in dollars per share)		$ 0.72	$ 0.67
[1]	Total other-than-temporary impairment (OTTI) gains (losses) were $0 and $(1) million for the three months ended March 31, 2018 and 2017, respectively. Of total OTTI, credit losses of $0 and $(2) million for the three months ended March 31, 2018 and 2017, respectively, were recognized in net realized investment gains (losses). In addition, unrealized gains from other changes in total OTTI of $0 and $1 million for the three months ended March 31, 2018 and 2017, respectively, were recognized in other comprehensive income (loss) as part of changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income.

Consolidated Statement of Inco3

Consolidated Statement of Income Parentheticals (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Statement [Abstract]
Total other-than-temporary impairment losses	$ 0	$ (1)
Other-than-temporary impairment, credit losses recognized in net realized investment gains	0	(2)
Unrealized gains from other changes in total other-than-temporary impairments recognized in other comprehensive income (loss) as part of changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	$ 0	$ 1

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 669	$ 617
Other comprehensive income (loss):
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	(1,203)	144
Changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	(2)
Net changes in benefit plan assets and obligations	22	17
Net changes in unrealized foreign currency translation	6	41
Other comprehensive income (loss) before income taxes	(1,177)	202
Income tax expense (benefit)	(244)	62
Other comprehensive income (loss), net of taxes	(933)	140
Comprehensive income (loss)	$ (264)	$ 757

Consolidated Balance Sheet (Una

Consolidated Balance Sheet (Unaudited at March 31, 2018) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Assets
Fixed maturities, available for sale, at fair value (amortized cost $62,093 and $61,316)	$ 62,266	$ 62,694
Equity securities, at fair value (cost $431)	430
Equity securities, available for sale, at fair value (cost $440)		453
Real estate investments	954	932
Short-term securities	4,486	4,895
Other investments	3,588	3,528
Total investments	71,724	72,502
Cash	397	344	$ 249	$ 307
Investment income accrued	567	606
Premiums receivable	7,536	7,144
Reinsurance recoverables	8,298	8,309
Ceded unearned premiums	777	551
Deferred acquisition costs	2,086	2,025
Deferred taxes	368	70
Contractholder receivables	4,835	4,775
Goodwill	3,959	3,951
Other intangible assets	341	342
Other assets	2,788	2,864
Total assets	103,676	103,483
Liabilities
Claims and claim adjustment expense reserves	49,810	49,650
Unearned premium reserves	13,424	12,915
Contractholder payables	4,835	4,775
Payables for reinsurance premiums	498	274
Debt	6,963	6,571
Other liabilities	5,167	5,567
Total liabilities	80,697	79,752
Shareholders’ equity
Common stock (1,750.0 shares authorized; 270.3 and 271.5 shares issued, 270.2 and 271.4 shares outstanding)	22,995	22,886
Retained earnings	33,981	33,462
Accumulated other comprehensive loss	(1,322)	(343)
Treasury stock, at cost (503.7 and 500.9 shares)	(32,675)	(32,274)
Total shareholders’ equity	22,979	23,731	$ 23,612
Total liabilities and shareholders’ equity	$ 103,676	$ 103,483

Consolidated Balance Sheet Pare

Consolidated Balance Sheet Parentheticals (Unaudited at March 31, 2018) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Fixed maturities, available for sale, amortized cost	$ 62,093	$ 61,316
Equity securities, cost	$ 431
Equity securities, available for sale, cost		$ 440
Common stock, shares authorized (in shares)	1,750,000,000	1,750,000,000
Common stock, shares issued (in shares)	270,300,000	271,500,000
Common stock, shares outstanding (in shares)	270,200,000	271,400,000
Treasury stock, at cost (in shares)	503,700,000	500,900,000

Consolidated Statement of Chang

Consolidated Statement of Changes in Shareholders' Equity (Unaudited) - USD ($) shares in Millions, $ in Millions	Total	Common stock [Member]	Retained earnings [Member]	Accumulated other comprehensive income (loss), net of tax [Member]	Treasury stock, at cost [Member]	Common shares outstanding [Member]
Balance, beginning of year at Dec. 31, 2016		$ 22,614	$ 32,196	$ (755)	$ (30,834)
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Employee share-based compensation		68
Compensation amortization under share-based plans		42
Net income	$ 617		617
Dividends			(190)
Other comprehensive income (loss)	140			140
Treasury stock acquired — share repurchase authorization					(225)
Net shares acquired related to employee share-based compensation plans					(61)
Balance, end of period at Mar. 31, 2017	23,612	22,724	32,623	(615)	(31,120)
Balance, beginning of year (in shares) at Dec. 31, 2016						279.6
Common shares outstanding
Treasury stock acquired - share repurchase authorization (in shares)						(1.9)
Net shares issued under employee share-based compensation plans (in shares)						1.7
Balance, end of period (in shares) at Mar. 31, 2017						279.4
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Cumulative effect of adoption of updated accounting guidance for equity financial instruments			22	(22)
Balance, beginning of year at Dec. 31, 2017	23,731	22,886	33,462	(343)	(32,274)
Increase (Decrease) in Shareholders' Equity [Roll Forward]
Employee share-based compensation		65
Compensation amortization under share-based plans		44
Reclassification of certain tax effects from adoption of updated accounting guidance			24	(24)
Net income	669		669
Dividends			(197)
Other			1
Other comprehensive income (loss)	(933)			(933)
Treasury stock acquired — share repurchase authorization	(350)				(350)
Net shares acquired related to employee share-based compensation plans	(51)				(51)
Balance, end of period at Mar. 31, 2018	$ 22,979	$ 22,995	$ 33,981	$ (1,322)	$ (32,675)
Balance, beginning of year (in shares) at Dec. 31, 2017	271.4					271.4
Common shares outstanding
Treasury stock acquired - share repurchase authorization (in shares)	(2.5)					(2.5)
Net shares issued under employee share-based compensation plans (in shares)						1.3
Balance, end of period (in shares) at Mar. 31, 2018	270.2					270.2

Consolidated Statement of Cash

Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities
Net income		$ 669	$ 617
Adjustments to reconcile net income to net cash provided by operating activities:
Net realized investment (gains) losses	[1]	11	(5)
Depreciation and amortization		212	211
Deferred federal income tax expense (benefit)		(56)	151
Amortization of deferred acquisition costs		1,061	1,003
Equity in income from other investments		(95)	(109)
Premiums receivable		(397)	(286)
Reinsurance recoverables		5	94
Deferred acquisition costs		(1,124)	(1,065)
Claims and claim adjustment expense reserves		180	334
Unearned premium reserves		518	475
Other operating activities		(430)	(572)
Net cash provided by operating activities		554	848
Cash flows from investing activities
Proceeds from maturities of fixed maturities		1,950	2,218
Proceeds from sales of investments:
Fixed maturities		1,085	188
Equity securities		26
Equity securities			21
Real estate investments			11
Other investments		114	122
Purchases of investments:
Fixed maturities		(3,920)	(3,056)
Equity securities		(20)
Equity securities			(22)
Real estate investments		(33)	(16)
Other investments		(142)	(124)
Net sales of short-term securities		410	49
Securities transactions in course of settlement		202	157
Other investing activities		(53)	(63)
Net cash used in investing activities		(381)	(515)
Cash flows from financing activities
Treasury stock acquired — share repurchase authorization		(350)	(225)
Treasury stock acquired — net employee share-based compensation		(51)	(61)
Dividends paid to shareholders		(197)	(190)
Payment of debt		(100)
Issuance of debt		491
Issuance of common stock — employee share options		85	83
Net cash used in financing activities		(122)	(393)
Effect of exchange rate changes on cash		2	2
Net increase (decrease) in cash		53	(58)
Cash at beginning of year		344	307
Cash at end of period		397	249
Supplemental disclosure of cash flow information
Income taxes paid		56	2
Interest paid		$ 39	$ 43
[1]	Total other-than-temporary impairment (OTTI) gains (losses) were $0 and $(1) million for the three months ended March 31, 2018 and 2017, respectively. Of total OTTI, credit losses of $0 and $(2) million for the three months ended March 31, 2018 and 2017, respectively, were recognized in net realized investment gains (losses). In addition, unrealized gains from other changes in total OTTI of $0 and $1 million for the three months ended March 31, 2018 and 2017, respectively, were recognized in other comprehensive income (loss) as part of changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income.

Basis of Presentation and Accou

Basis of Presentation and Accounting Policies	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation and Accounting Policies	BASIS OF PRESENTATION AND ACCOUNTING POLICIES Basis of Presentation The interim consolidated financial statements include the accounts of The Travelers Companies, Inc. (together with its subsidiaries, the Company). These financial statements are prepared in conformity with U.S. generally accepted accounting principles (GAAP) and are unaudited. In the opinion of the Company’s management, all adjustments necessary for a fair presentation have been reflected. Certain financial information that is normally included in annual financial statements prepared in accordance with GAAP, but that is not required for interim reporting purposes, has been omitted. All material intercompany transactions and balances have been eliminated. The accompanying interim consolidated financial statements and related notes should be read in conjunction with the Company’s consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 (the Company’s 2017 Annual Report). The preparation of the interim consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the interim consolidated financial statements and the reported amounts of revenues and claims and expenses during the reporting period. Actual results could differ from those estimates. Certain reclassifications have been made to the 2017 financial statements to conform to the 2018 presentation. Adoption of Accounting Standards Financial Instruments: Recognition and Measurement of Financial Assets and Financial Liabilities In January 2016, the Financial Accounting Standards Board (FASB) issued updated guidance to address the recognition, measurement, presentation and disclosure of certain financial instruments. The updated guidance requires equity investments, except those accounted for under the equity method of accounting, that have readily determinable fair value to be measured at fair value with any changes in fair value recognized in net income. Equity securities that do not have readily determinable fair values may be measured at estimated fair value or cost less impairment, if any, adjusted for subsequent observable price changes, with changes in the carrying value recognized in net income. A qualitative assessment for impairment is required for equity investments without readily determinable fair values. The updated guidance also eliminates the requirement to disclose the method and significant assumptions used to estimate the fair value of financial instruments measured at amortized cost on the balance sheet. The updated guidance was effective for the quarter ended March 31, 2018. The adoption of this guidance resulted in the recognition of $22 million of net after-tax unrealized gains on equity investments as a cumulative effect adjustment that increased retained earnings as of January 1, 2018 and decreased accumulated other comprehensive income (AOCI) by the same amount. The Company elected to report changes in the fair value of equity investments in net realized investment gains (losses). At December 31, 2017, equity investments were classified as available-for-sale on the Company's balance sheet. However, upon adoption, the updated guidance eliminated the available-for-sale balance sheet classification for equity investments. Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income On February 14, 2018, the FASB issued updated guidance that allows a reclassification from AOCI to retained earnings of the stranded tax effects that occurred due to the enactment of the Tax Cuts and Jobs Act of 2017 (TCJA). The updated guidance is effective for reporting periods beginning after December 15, 2018 and is to be applied retrospectively to each period in which there are items impacted by the TCJA remaining in AOCI or at the beginning of the period of adoption. Early adoption is permitted. The Company adopted the updated guidance effective January 1, 2018 and elected to reclassify the income tax effects of the TCJA from AOCI to retained earnings as of January 1, 2018. This reclassification resulted in an increase in retained earnings of $24 million as of January 1, 2018 and a decrease in AOCI by the same amount. Revenue from Contracts with Customers In May 2014, the FASB issued updated guidance to clarify the principles for recognizing revenue. The updated guidance was effective for reporting periods beginning after December 15, 2017, and requires an entity to recognize revenue as performance obligations are met, in order to reflect the transfer of goods or services to customers in an amount that reflects the consideration the entity is entitled to receive for those goods or services. For the three months ended March 31, 2018, approximately $40 million , or less than 1% of the Company's total revenues, were within the scope of this updated guidance and were generated from the services described below. While insurance contracts are not within the scope of this updated guidance, the Company’s revenue related to certain services with no underlying insurance risk is subject to the updated guidance. These services include the following: (i) insurance-related services, such as risk management services, claims administration, loss control and risk management information services on behalf of non-insureds; (ii) servicing carrier fees for various residual market pools and associations; and (iii) administrative fees related to servicing third-party insurers’ obligations to participate in the Workers' Compensation Residual Market Plans in certain states. The revenues earned from these service contracts were not impacted by the adoption of the updated guidance. These revenues are earned on a pro rata basis over the contract service period and reported in fee income in the Company’s consolidated statement of income. Commissions earned from on-line insurance brokerage services are also subject to this updated guidance and were also not impacted by the adoption of the updated guidance. Commissions are earned upon collection of the gross premium in accordance with the contracts and an accrual is made to recognize policy cancellations, either at the policyholder’s direction or for non-payment. Commissions are reported in other revenues in the Company's consolidated statement of income. The Company does not capitalize the costs to obtain or fulfill the contracts for which revenues are reported in fee income and other income, and has not recognized any impairment losses on the receivables related to these contracts during the three months ended March 31, 2018. The Company adopted the updated guidance effective January 1, 2018. The adoption did not have an effect on the Company’s results of operations, financial position or liquidity. Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments In August 2016, the FASB issued updated guidance on the classification of cash flows related to certain activities in the statement of cash flows to reduce diversity in practice. The updated guidance was effective for reporting periods beginning after December 15, 2017 and was applied retrospectively to all periods presented. Under the new guidance, distributions received on equity method investments that are considered to be a return on investment are reported as cash flows from operating activities. These distributions were previously reported as cash flows from investing activities. The adoption of this guidance had no effect on the Company’s results of operations, financial position or liquidity. For information regarding accounting standards that the Company adopted during the years presented, see the “Adoption of Accounting Standards ” section of note 1 of notes to the consolidated financial statements in the Company’s 2017 Annual Report. Accounting Standards Not Yet Adopted For information regarding accounting standards that the Company has not yet adopted, see the “Other Accounting Standards Not Yet Adopted ” section of note 1 of notes to the consolidated financial statements in the Company’s 2017 Annual Report. Nature of Operations The Company’s results are reported in the following three business segments — Business Insurance, Bond & Specialty Insurance and Personal Insurance. These segments reflect the manner in which the Company’s businesses are currently managed and represent an aggregation of products and services based on the type of customer, how the business is marketed and the manner in which risks are underwritten. For more information regarding the Company’s nature of operations, see the “Nature of Operations ” section of note 1 of notes to the consolidated financial statements in the Company’s 2017 Annual Report.

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Segment Information	SEGMENT INFORMATION The following tables summarize the components of the Company’s revenues, income and total assets by reportable business segments: (For the three months ended March 31, in millions) Business Insurance Bond & Specialty Insurance Personal Insurance Total Reportable Segments 2018 Premiums $ 3,568 $ 582 $ 2,387 $ 6,537 Net investment income 446 58 99 603 Fee income 99 — 4 103 Other revenues 31 6 17 54 Total segment revenues (1) $ 4,144 $ 646 $ 2,507 $ 7,297 Segment income (1) $ 452 $ 173 $ 129 $ 754 2017 Premiums $ 3,429 $ 555 $ 2,199 $ 6,183 Net investment income 453 61 96 610 Fee income 109 — 4 113 Other revenues 9 5 16 30 Total segment revenues (1) $ 4,000 $ 621 $ 2,315 $ 6,936 Segment income (1) $ 442 $ 145 $ 89 $ 676 _________________________________________________________ (1) Segment revenues for reportable business segments exclude net realized investment gains (losses). Segment income for reportable business segments equals net income excluding the after-tax impact of net realized investment gains (losses). Business Segment Reconciliations Three Months Ended (in millions) 2018 2017 Revenue reconciliation Earned premiums Business Insurance: Domestic: Workers’ compensation $ 971 $ 976 Commercial automobile 562 506 Commercial property 438 435 General liability 521 491 Commercial multi-peril 805 774 Other 7 7 Total Domestic 3,304 3,189 International 264 240 Total Business Insurance 3,568 3,429 Bond & Specialty Insurance: Domestic: Fidelity and surety 246 234 General liability 242 235 Other 47 45 Total Domestic 535 514 International 47 41 Total Bond & Specialty Insurance 582 555 Personal Insurance: Domestic: Automobile 1,225 1,094 Homeowners and Other 995 955 Total Domestic 2,220 2,049 International 167 150 Total Personal Insurance 2,387 2,199 Total earned premiums 6,537 6,183 Net investment income 603 610 Fee income 103 113 Other revenues 54 30 Total segment revenues 7,297 6,936 Other revenues — 1 Net realized investment gains (losses) (11 ) 5 Total revenues $ 7,286 $ 6,942 Income reconciliation, net of tax Total segment income $ 754 $ 676 Interest Expense and Other (1) (76 ) (62 ) Core income 678 614 Net realized investment gains (losses) (9 ) 3 Net income $ 669 $ 617 _________________________________________________________ (1) The primary component of Interest Expense and Other was after-tax interest expense of $70 million and $58 million in the three months ended March 31, 2018 and 2017 , respectively. (in millions) March 31, December 31, Asset reconciliation Business Insurance $ 78,747 $ 78,082 Bond & Specialty Insurance 8,787 8,776 Personal Insurance 15,605 15,949 Total segment assets 103,139 102,807 Other assets (1) 537 676 Total consolidated assets $ 103,676 $ 103,483 _________________________________________________________ (1) The primary components of other assets at March 31, 2018 were accrued over-funded benefit plan assets related to the Company’s qualified domestic pension plan and other intangible assets, and the primary components at December 31, 2017 were accrued over-funded benefit plan assets related to the Company’s qualified domestic pension plan, other intangible assets and deferred taxes.

Investments

Investments	3 Months Ended
	Mar. 31, 2018
Investments [Abstract]
Investments	INVESTMENTS Fixed Maturities The amortized cost and fair value of investments in fixed maturities classified as available for sale were as follows: Amortized Gross Unrealized Fair (at March 31, 2018, in millions) Cost Gains Losses Value U.S. Treasury securities and obligations of U.S. government and government agencies and authorities $ 2,051 $ 2 $ 19 $ 2,034 Obligations of states, municipalities and political subdivisions: Local general obligation 13,593 215 127 13,681 Revenue 10,512 177 91 10,598 State general obligation 1,391 21 12 1,400 Pre-refunded 3,638 123 — 3,761 Total obligations of states, municipalities and political subdivisions 29,134 536 230 29,440 Debt securities issued by foreign governments 1,326 9 8 1,327 Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 2,495 76 40 2,531 All other corporate bonds 27,000 231 389 26,842 Redeemable preferred stock 87 5 — 92 Total $ 62,093 $ 859 $ 686 $ 62,266 Amortized Gross Unrealized Fair (at December 31, 2017, in millions) Cost Gains Losses Value U.S. Treasury securities and obligations of U.S. government and government agencies and authorities $ 2,080 $ 4 $ 8 $ 2,076 Obligations of states, municipalities and political subdivisions: Local general obligation 13,488 444 26 13,906 Revenue 11,307 338 19 11,626 State general obligation 1,443 44 3 1,484 Pre-refunded 3,758 142 1 3,899 Total obligations of states, municipalities and political subdivisions 29,996 968 49 30,915 Debt securities issued by foreign governments 1,505 14 10 1,509 Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 2,334 87 11 2,410 All other corporate bonds 25,311 478 100 25,689 Redeemable preferred stock 90 5 — 95 Total $ 61,316 $ 1,556 $ 178 $ 62,694 Pre-refunded bonds of $3.76 billion and $3.90 billion at March 31, 2018 and December 31, 2017 , respectively, were bonds for which states or municipalities have established irrevocable trusts, almost exclusively comprised of U.S. Treasury securities and obligations of U.S. government and government agencies and authorities. These trusts were created to fund the payment of principal and interest due under the bonds. Proceeds from sales of fixed maturities classified as available for sale were $1.09 billion and $188 million during the three months ended March 31, 2018 and 2017 , respectively. Gross gains of $6 million and $7 million and gross losses of $6 million and $2 million were realized on those sales during the three months ended March 31, 2018 and 2017 , respectively. Equity Securities The cost and fair value of investments in equity securities were as follows: Fair (at March 31, 2018, in millions) Cost Gross Gains Gross Losses Value Public common stock $ 330 $ 4 $ 10 $ 324 Non-redeemable preferred stock 101 11 6 106 Total $ 431 $ 15 $ 16 $ 430 Fair (at December 31, 2017, in millions) Cost Gross Gains Gross Losses Value Public common stock $ 332 $ 8 $ 1 $ 339 Non-redeemable preferred stock 108 12 6 114 Total $ 440 $ 20 $ 7 $ 453 For the three months ended March 31, 2018, the Company recognized $13 million of net losses on equity securities still held as of March 31, 2018 . Proceeds from sales of equity securities previously classified as available for sale were $21 million during the three months ended March 31, 2017 . Gross gains of $6 million and gross losses of less than $1 million were realized on those sales during the three months ended March 31, 2017 . Unrealized Investment Losses The following tables summarize, for all investments in an unrealized loss position at March 31, 2018 and December 31, 2017 , the aggregate fair value and gross unrealized loss by length of time those securities have been continuously in an unrealized loss position. The fair value amounts reported in the tables are estimates that are prepared using the process described in note 4 herein and in note 4 of notes to the consolidated financial statements in the Company’s 2017 Annual Report. The Company also relies upon estimates of several factors in its review and evaluation of individual investments, using the process described in note 1 of notes to the consolidated financial statements in the Company’s 2017 Annual Report in determining whether such investments are other-than-temporarily impaired. Less than 12 months 12 months or longer Total (at March 31, 2018, in millions) Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fixed maturities U.S. Treasury securities and obligations of U.S. government and government agencies and authorities $ 1,332 $ 15 $ 549 $ 4 $ 1,881 $ 19 Obligations of states, municipalities and political subdivisions 5,823 94 2,863 136 8,686 230 Debt securities issued by foreign governments 431 7 32 1 463 8 Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 1,474 32 235 8 1,709 40 All other corporate bonds 14,816 294 1,910 95 16,726 389 Total fixed maturities $ 23,876 $ 442 $ 5,589 $ 244 $ 29,465 $ 686 Less than 12 months 12 months or Total (at December 31, 2017, in millions) Fair Gross Fair Gross Fair Gross Unrealized Losses Fixed maturities U.S. Treasury securities and obligations of U.S. government and government agencies and authorities $ 1,150 $ 5 $ 470 $ 3 $ 1,620 $ 8 Obligations of states, municipalities and political subdivisions 505 2 2,959 47 3,464 49 Debt securities issued by foreign governments 394 6 111 4 505 10 Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 1,021 7 250 4 1,271 11 All other corporate bonds 6,062 48 1,990 52 8,052 100 Total fixed maturities 9,132 68 5,780 110 14,912 178 Equity securities Public common stock 18 — 34 1 52 1 Non-redeemable preferred stock 3 — 56 6 59 6 Total equity securities 21 — 90 7 111 7 Total $ 9,153 $ 68 $ 5,870 $ 117 $ 15,023 $ 185 At March 31, 2018 , the Company had no fixed maturity investments reported at fair value for which fair value was less than 80% of amortized cost. Impairment Charges Impairment charges included in net realized investment gains (losses) in the consolidated statement of income were $0 and $2 million for the three months ended March 31, 2018 and 2017 , respectively. The cumulative amount of credit losses on fixed maturities held at March 31, 2018 and 2017 that were recognized in the consolidated statement of income from other-than-temporary impairments (OTTI) and for which a portion of the OTTI was recognized in other comprehensive income (loss) in the consolidated balance sheet was $75 million and $83 million , respectively. These credit losses represent less than 1% of the fixed maturity portfolio on a pre-tax basis and less than 1% of shareholders’ equity on an after-tax basis at both dates. There were no significant changes in the credit component of OTTI during the three months ended March 31, 2018 and 2017 from that disclosed in note 3 of notes to the consolidated financial statements in the Company’s 2017 Annual Report. Derivative Financial Instruments From time to time, the Company enters into U.S. Treasury note futures contracts to modify the effective duration of specific assets within the investment portfolio. U.S. Treasury futures contracts require a daily mark-to-market and settlement with the broker. At March 31, 2018 and December 31, 2017 , the Company had $ 250 million and $400 million notional value of open U.S. Treasury futures contracts, respectively. Net realized investment gains and losses related to U.S. Treasury futures contracts for the three months ended March 31, 2018 and 2017 were not significant.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The Company’s estimates of fair value for financial assets and financial liabilities are based on the framework established in the fair value accounting guidance. The framework is based on the inputs used in valuation, gives the highest priority to quoted prices in active markets and requires that observable inputs be used in the valuations when available. The disclosure of fair value estimates in the fair value accounting guidance hierarchy is based on whether the significant inputs into the valuation are observable. In determining the level of the hierarchy in which the estimate is disclosed, the highest priority is given to unadjusted quoted prices in active markets and the lowest priority to unobservable inputs that reflect the Company’s significant market assumptions. The level in the fair value hierarchy within which the fair value measurement is reported is based on the lowest level input that is significant to the measurement in its entirety. The three levels of the hierarchy are as follows: • Level 1 - Unadjusted quoted market prices for identical assets or liabilities in active markets that the Company has the ability to access. • Level 2 - Quoted prices for similar assets or liabilities in active markets; quoted prices for identical or similar assets or liabilities in inactive markets; or valuations based on models where the significant inputs are observable (e.g., interest rates, yield curves, prepayment speeds, default rates, loss severities, etc.) or can be corroborated by observable market data. • Level 3 - Valuations based on models where significant inputs are not observable. The unobservable inputs reflect the Company’s own assumptions about the inputs that market participants would use. Valuation of Investments Reported at Fair Value in Financial Statements The Company utilized a pricing service to estimate fair value measurements for approximately 98% of its fixed maturities at both March 31, 2018 and December 31, 2017 . While the vast majority of the Company’s fixed maturities are included in Level 2, the Company holds a number of municipal bonds and corporate bonds which are not valued by the pricing service and estimates the fair value of these bonds using an internal pricing matrix with some unobservable inputs that are significant to the valuation. Due to the limited amount of observable market information, the Company includes the fair value estimates for these particular bonds in Level 3. The fair value of the fixed maturities for which the Company used an internal pricing matrix was $146 million and $127 million at March 31, 2018 and December 31, 2017 , respectively. Additionally, the Company holds a small amount of other fixed maturity investments that have characteristics that make them unsuitable for matrix pricing. For these fixed maturities, the Company obtains a quote from a broker (primarily the market maker). The fair value of the fixed maturities for which the Company received a broker quote was $101 million and $77 million at March 31, 2018 and December 31, 2017 , respectively. Due to the disclaimers on the quotes that indicate that the price is indicative only, the Company includes these fair value estimates in Level 3. For more information regarding the valuation of the Company’s fixed maturities, equity securities and other investments, see note 4 of notes to the consolidated financial statements in the Company’s 2017 Annual Report. Fair Value Hierarchy The following tables present the level within the fair value hierarchy at which the Company’s financial assets and financial liabilities are measured on a recurring basis. An investment transferred between levels during a period is transferred at its fair value as of the beginning of that period. (at March 31, 2018, in millions) Total Level 1 Level 2 Level 3 Invested assets: Fixed maturities U.S. Treasury securities and obligations of U.S. government and government agencies and authorities $ 2,034 $ 2,034 $ — $ — Obligations of states, municipalities and political subdivisions 29,440 — 29,428 12 Debt securities issued by foreign governments 1,327 — 1,327 — Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 2,531 — 2,491 40 All other corporate bonds 26,842 1 26,646 195 Redeemable preferred stock 92 3 89 — Total fixed maturities 62,266 2,038 59,981 247 Equity securities Public common stock 324 324 — — Non-redeemable preferred stock 106 42 64 — Total equity securities 430 366 64 — Other investments 55 17 — 38 Total $ 62,751 $ 2,421 $ 60,045 $ 285 (at December 31, 2017, in millions) Total Level 1 Level 2 Level 3 Invested assets: Fixed maturities U.S. Treasury securities and obligations of U.S. government and government agencies and authorities $ 2,076 $ 2,076 $ — $ — Obligations of states, municipalities and political subdivisions 30,915 — 30,910 5 Debt securities issued by foreign governments 1,509 — 1,509 — Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 2,410 — 2,371 39 All other corporate bonds 25,689 11 25,518 160 Redeemable preferred stock 95 3 92 — Total fixed maturities 62,694 2,090 60,400 204 Equity securities Public common stock 339 339 — — Non-redeemable preferred stock 114 45 69 — Total equity securities 453 384 69 — Other investments 57 19 — 38 Total $ 63,204 $ 2,493 $ 60,469 $ 242 During the three months ended March 31, 2018 and the year ended December 31, 2017 , the Company’s transfers between Level 1 and Level 2 were not significant. There was no significant activity in Level 3 of the hierarchy during the three months ended March 31, 2018 or the year ended December 31, 2017 . Financial Instruments Disclosed, But Not Carried, At Fair Value The following tables present the carrying value and fair value of the Company’s financial assets and financial liabilities disclosed, but not carried, at fair value, and the level within the fair value hierarchy at which such assets and liabilities are categorized. (at March 31, 2018, in millions) Carrying Value Fair Value Level 1 Level 2 Level 3 Financial assets: Short-term securities $ 4,486 $ 4,486 $ 835 $ 3,612 $ 39 Financial liabilities: Debt $ 6,963 $ 7,835 $ — $ 7,835 $ — (at December 31, 2017, in millions) Carrying Value Fair Value Level 1 Level 2 Level 3 Financial assets: Short-term securities $ 4,895 $ 4,895 $ 1,238 $ 3,622 $ 35 Financial liabilities: Debt $ 6,471 $ 7,702 $ — $ 7,702 $ — Commercial paper $ 100 $ 100 $ — $ 100 $ — The Company had no material assets or liabilities that were measured at fair value on a non-recurring basis during the three months ended March 31, 2018 or year ended December 31, 2017 .

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	GOODWILL AND OTHER INTANGIBLE ASSETS Goodwill The following table presents the carrying amount of the Company’s goodwill by segment. Each reportable segment includes goodwill associated with the Company’s international business which is subject to the impact of changes in foreign currency exchange rates. (in millions) March 31, December 31, Business Insurance $ 2,597 $ 2,585 Bond & Specialty Insurance 550 550 Personal Insurance 786 790 Other 26 26 Total $ 3,959 $ 3,951 Other Intangible Assets The following tables present a summary of the Company’s other intangible assets by major asset class. (at March 31, 2018, in millions) Gross Carrying Amount Accumulated Amortization Net Subject to amortization Customer-related $ 80 $ 5 $ 75 Contract-based (1) 209 170 39 Total subject to amortization 289 175 114 Not subject to amortization 227 — 227 Total $ 516 $ 175 $ 341 (at December 31, 2017, in millions) Gross Carrying Amount Accumulated Amortization Net Subject to amortization Customer-related $ 77 $ 4 $ 73 Contract-based (1) 209 167 42 Total subject to amortization 286 171 115 Not subject to amortization 227 — 227 Total $ 513 $ 171 $ 342 _________________________________________________________ (1) Contract-based intangible assets subject to amortization are comprised of fair value adjustments on claims and claim adjustment expense reserves, reinsurance recoverables and other contract-related intangible assets. Fair value adjustments recorded in connection with insurance acquisitions were based on management’s estimate of nominal claims and claim adjustment expense reserves and reinsurance recoverables. The method used calculated a risk adjustment to a risk-free discounted reserve that would, if reserves ran off as expected, produce results that yielded the assumed cost-of-capital on the capital supporting the loss reserves. The fair value adjustments are reported as other intangible assets on the consolidated balance sheet, and the amounts measured in accordance with the acquirer’s accounting policies for insurance contracts have been reported as part of the claims and claim adjustment expense reserves and reinsurance recoverables. The intangible assets are being recognized into income over the expected payment pattern. Because the time value of money and the risk adjustment (cost of capital) components of the intangible assets run off at different rates, the amount recognized in income may be a net benefit in some periods and a net expense in other periods. Amortization expense of intangible assets was $4 million and $3 million for the three months ended March 31, 2018 and 2017 , respectively. Intangible asset amortization expense is estimated to be $11 million for the remainder of 2018 , $14 million in 2019 , $13 million in 2020 , $12 million in 2021 and $11 million in 2022 .

Insurance Claim Reserves

Insurance Claim Reserves	3 Months Ended
	Mar. 31, 2018
Insurance Loss Reserves [Abstract]
Insurance Claim Reserves	INSURANCE CLAIM RESERVES Claims and claim adjustment expense reserves were as follows: (in millions) March 31, December 31, Property-casualty $ 49,794 $ 49,633 Accident and health 16 17 Total $ 49,810 $ 49,650 The following table presents a reconciliation of beginning and ending property casualty reserve balances for claims and claim adjustment expenses for the three months ended March 31, 2018 and 2017 : (for the three months ended March 31, in millions) 2018 2017 Claims and claim adjustment expense reserves at beginning of year $ 49,633 $ 47,929 Less reinsurance recoverables on unpaid losses 8,123 7,981 Net reserves at beginning of year 41,510 39,948 Estimated claims and claim adjustment expenses for claims arising in the current year 4,391 4,126 Estimated decrease in claims and claim adjustment expenses for claims arising in prior years (116 ) (50 ) Total increases 4,275 4,076 Claims and claim adjustment expense payments for claims arising in: Current year 1,009 887 Prior years 3,040 2,812 Total payments 4,049 3,699 Unrealized foreign exchange (gain) loss (10 ) 34 Net reserves at end of period 41,726 40,359 Plus reinsurance recoverables on unpaid losses 8,068 7,942 Claims and claim adjustment expense reserves at end of period $ 49,794 $ 48,301 Gross claims and claim adjustment expense reserves at March 31, 2018 increased by $161 million from December 31, 2017 , primarily reflecting the impacts of (i) higher volumes of insured exposures and loss cost trends for the current accident year and (ii) catastrophe losses in the first quarter of 2018, partially offset by the impacts of (iii) payments related to catastrophe losses incurred in 2017, (iv) net favorable prior year reserve development and (v) payments related to operations in runoff. Reinsurance recoverables on unpaid losses at March 31, 2018 decreased by $55 million from December 31, 2017 , primarily reflecting the impacts of cash collections in the first three months of 2018. Prior Year Reserve Development The following disclosures regarding reserve development are on a “net of reinsurance” basis. For the three months ended March 31, 2018 and 2017 , estimated claims and claim adjustment expenses incurred included $116 million and $50 million , respectively, of net favorable development for claims arising in prior years, including $150 million and $81 million , respectively, of net favorable prior year reserve development and $13 million of accretion of discount in each period that impacted the Company's results of operations. Business Insurance. Net favorable prior year reserve development in the first quarter of 2018 totaled $66 million , primarily driven by better than expected loss experience in the segment’s domestic operations in (i) the workers’ compensation product line for recent accident years and (ii) the commercial property product line for accident year 2016, partially offset by (iii) higher than expected loss experience in the commercial automobile product line for recent accident years. Net favorable prior year reserve development in the first quarter of 2017 totaled $61 million , primarily driven by better than expected loss experience in the segment's domestic operations in (i) the workers’ compensation product line for multiple accident years and (ii) the general liability product line for both primary and excess coverages for accident years 2009 and prior as well as accident year 2014, partially offset by (iii) net unfavorable prior year reserve development in the Company’s international operations in Europe due to the U.K. Ministry of Justice’s “Ogden” discount rate adjustment applied to lump sum bodily injury payouts. Bond & Specialty Insurance. Net favorable prior year reserve development in the first quarter of 2018 totaled $35 million , primarily driven by better than expected loss experience in the segment’s domestic operations in the general liability product line for multiple accident years. Net favorable prior year reserve development in the first quarter of 2017 totaled $14 million . Personal Insurance. Net favorable prior year reserve development in the first quarter of 2018 totaled $49 million , primarily driven by better than expected loss experience in the segment's domestic operations in the Homeowners and Other product line for accident years 2016 and 2017 and in the Automobile product line for accident year 2017. Net favorable prior year reserve development in the first quarter of 2017 totaled $6 million .

Other Comprehensive Income and

Other Comprehensive Income and Accumulated Other Comprehensive Income	3 Months Ended
	Mar. 31, 2018
Other Comprehensive Income and Accumulated Other Comprehensive Income disclosure
Other Comprehensive Income and Accumulated Other Comprehensive Income	OTHER COMPREHENSIVE INCOME AND ACCUMULATED OTHER COMPREHENSIVE INCOME The following table presents the changes in the Company’s accumulated other comprehensive income (loss) (AOCI) for the three months ended March 31, 2018 . Changes in Net Unrealized Gains on Investment Securities (in millions) Having No Credit Losses Recognized in the Consolidated Statement of Income Having Credit Losses Recognized in the Consolidated Statement of Income Net Benefit Plan Assets and Obligations Recognized in Shareholders’ Equity Net Unrealized Foreign Currency Translation Total Accumulated Other Comprehensive Income (Loss) Balance, December 31, 2017 $ 747 $ 207 $ (686 ) $ (611 ) $ (343 ) Cumulative effect of adoption of updated accounting guidance for equity financial instruments at January 1, 2018 (34 ) — — — (34 ) Income tax benefit (12 ) — — — (12 ) Net of income taxes (22 ) — — — (22 ) Reclassification of certain tax effects from accumulated other comprehensive income at January 1, 2018 145 7 (141 ) (35 ) (24 ) Total effect of adoption of new guidance at January 1, 2018, net of tax 123 7 (141 ) (35 ) (46 ) Other comprehensive income (loss) (OCI) before reclassifications, net of tax (950 ) (1 ) — 1 (950 ) Amounts reclassified from AOCI, net of tax — — 17 — 17 Net OCI, current period (950 ) (1 ) 17 1 (933 ) Balance, March 31, 2018 $ (80 ) $ 213 $ (810 ) $ (645 ) $ (1,322 ) The following table presents the pre-tax components of the Company’s other comprehensive income (loss) and the related income tax expense (benefit). Three Months Ended (in millions) 2018 2017 Changes in net unrealized gains on investment securities: Having no credit losses recognized in the consolidated statement of income $ (1,203 ) $ 144 Income tax expense (benefit) (253 ) 51 Net of taxes (950 ) 93 Having credit losses recognized in the consolidated statement of income (2 ) — Income tax benefit (1 ) — Net of taxes (1 ) — Net changes in benefit plan assets and obligations 22 17 Income tax expense 5 5 Net of taxes 17 12 Net changes in unrealized foreign currency translation 6 41 Income tax expense 5 6 Net of taxes 1 35 Total other comprehensive income (loss) (1,177 ) 202 Total income tax expense (benefit) (244 ) 62 Total other comprehensive income (loss), net of taxes $ (933 ) $ 140 The following table presents the pre-tax and related income tax (expense) benefit components of the amounts reclassified from the Company’s AOCI to the Company’s consolidated statement of income. Three Months Ended (in millions) 2018 2017 Reclassification adjustments related to unrealized gains on investment securities: Having no credit losses recognized in the consolidated statement of income (1) $ — $ (10 ) Income tax expense (2) — (3 ) Net of taxes — (7 ) Having credit losses recognized in the consolidated statement of income (1) — — Income tax benefit (2) — — Net of taxes — — Reclassification adjustment related to benefit plan assets and obligations: Claims and claim adjustment expenses (3) 9 7 General and administrative expenses (3) 13 10 Total 22 17 Income tax benefit (2) 5 5 Net of taxes 17 12 Reclassification adjustment related to foreign currency translation (1) — — Income tax benefit (2) — — Net of taxes — — Total reclassifications 22 7 Total income tax benefit 5 2 Total reclassifications, net of taxes $ 17 $ 5 _________________________________________________________ (1) (Increases) decreases net realized investment gains (losses) on the consolidated statement of income. (2) (Increases) decreases income tax expense on the consolidated statement of income. (3) Increases (decreases) expenses on the consolidated statement of income.

Debt

Debt	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Debt	DEBT Debt Issuance . On March 7, 2018, the Company issued $500 million aggregate principal amount of 4.05% senior notes that will mature on March 7, 2048. The net proceeds of the issuance, after the deduction of the underwriting discount and expenses payable by the Company, totaled approximately $491 million . Interest on the senior notes is payable semi-annually in arrears on March 7 and September 7, commencing on September 7, 2018. Prior to September 7, 2047, the senior notes may be redeemed, in whole or in part, at the Company’s option, at any time or from time to time, at a redemption price equal to the greater of (a) 100% of the principal amount of any senior notes to be redeemed or (b) the sum of the present values of the remaining scheduled payments of principal and interest to but excluding September 7, 2047 on any senior notes to be redeemed (exclusive of interest accrued to the date of redemption) discounted to the date of redemption on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) at the then current Treasury rate (as defined in the senior notes), plus 15 basis points. On or after September 7, 2047, the senior notes may be redeemed, in whole or in part, at the Company’s option, at any time or from time to time, at a redemption price equal to 100% of the principal amount of any senior notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. Commercial Paper. The Company had $0 and $100 million of commercial paper outstanding at March 31, 2018 and December 31, 2017 , respectively.

Common Share Repurchases

Common Share Repurchases	3 Months Ended
	Mar. 31, 2018
Treasury Stock Transactions, Excluding Value of Shares Reissued [Abstract]
Common Share Repurchases	COMMON SHARE REPURCHASES During the three months ended March 31, 2018 , the Company repurchased 2.5 million shares under its share repurchase authorization, for a total cost of $350 million . The average cost per share repurchased was $141.84 . In addition, the Company acquired 0.3 million shares for a total cost of $51 million during the three months ended March 31, 2018 , that were not part of the publicly announced share repurchase authorization. These shares consisted of shares retained to cover payroll withholding taxes in connection with the vesting of restricted stock unit awards and performance share awards, and shares used by employees to cover the price of certain stock options that were exercised. At March 31, 2018 , the Company had $4.21 billion of capacity remaining under its share repurchase authorization.

Earnings per Share

Earnings per Share	3 Months Ended
	Mar. 31, 2018
Earnings Per Share Reconciliation [Abstract]
Earnings per Share	EARNINGS PER SHARE The following is a reconciliation of the net income and share data used in the basic and diluted earnings per share computations for the periods presented: Three Months Ended (in millions, except per share amounts) 2018 2017 Basic and Diluted Net income, as reported $ 669 $ 617 Participating share-based awards — allocated income (5 ) (4 ) Net income available to common shareholders — basic and diluted $ 664 $ 613 Common Shares Basic Weighted average shares outstanding 271.0 279.7 Diluted Weighted average shares outstanding 271.0 279.7 Weighted average effects of dilutive securities — stock options and performance shares 2.9 2.7 Total 273.9 282.4 Net Income per Common Share Basic $ 2.45 $ 2.19 Diluted $ 2.42 $ 2.17

Share-Based Incentive Compensat

Share-Based Incentive Compensation	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Incentive Compensation	SHARE-BASED INCENTIVE COMPENSATION The following information relates to fully vested stock option awards at March 31, 2018 : Stock Options Number Weighted Average Exercise Price Weighted Average Contractual Life Remaining Aggregate Intrinsic Value ($ in millions) Vested at end of period (1) 6,207,090 $ 98.23 6.6 years $ 253 Exercisable at end of period 3,696,007 $ 84.13 5.2 years $ 202 _________________________________________________________ (1) Represents awards for which the requisite service has been rendered, including those that are retirement eligible. The total compensation cost for all share-based incentive compensation awards recognized in earnings was $44 million and $42 million for the three months ended March 31, 2018 and 2017 , respectively. The related tax benefits recognized in the consolidated statement of income were $8 million and $14 million for the three months ended March 31, 2018 and 2017 , respectively. The total unrecognized compensation cost related to all nonvested share-based incentive compensation awards at March 31, 2018 was $233 million , which is expected to be recognized over a weighted-average period of 2.2 years .

Pension Plans, Retirement Benef

Pension Plans, Retirement Benefits and Savings Plans	3 Months Ended
	Mar. 31, 2018
Retirement Benefits [Abstract]
Pension Plans, Retirement Benefits and Savings Plans	PENSION PLANS, RETIREMENT BENEFITS AND SAVINGS PLANS The following table summarizes the components of net periodic benefit cost for the Company’s pension and postretirement benefit plans recognized in the consolidated statement of income for the three months ended March 31, 2018 and 2017 . Pension Plans Postretirement Benefit Plans (for the three months ended March 31, in millions) 2018 2017 2018 2017 Net Periodic Benefit Cost: Service cost $ 33 $ 30 $ — $ — Non-service cost: Interest cost on benefit obligation 31 31 2 2 Expected return on plan assets (66 ) (60 ) — — Amortization of unrecognized: Prior service benefit — — (1 ) (1 ) Net actuarial loss 23 18 — — Total non-service cost (benefit) (12 ) (11 ) 1 1 Net periodic benefit cost $ 21 $ 19 $ 1 $ 1 The following table indicates the line items in which the respective service costs and non-service benefit costs are presented in the consolidated statement of income for the three months ended March 31, 2018 and 2017 . Pension Plans Postretirement Benefit Plans (for the three months ended March 31, in millions) 2018 2017 2018 2017 Service Cost: Claims and claim adjustment expenses $ 13 $ 12 $ — $ — General and administrative expenses 20 18 — — Total service cost 33 30 — — Non-Service Cost: Claims and claim adjustment expenses (5 ) (4 ) — — General and administrative expenses (7 ) (7 ) 1 1 Total non-service cost (benefit) (12 ) (11 ) 1 1 Net periodic benefit cost $ 21 $ 19 $ 1 $ 1

Contingencies, Commitments and

Contingencies, Commitments and Guarantees	3 Months Ended
	Mar. 31, 2018
Contingencies, Commitments and Guarantees disclosure
Contingencies, Commitments and Guarantees	CONTINGENCIES, COMMITMENTS AND GUARANTEES Contingencies The major pending legal proceedings, other than ordinary routine litigation incidental to the business, to which the Company or any of its subsidiaries is a party or to which any of the Company’s properties is subject are described below. Asbestos and Environmental Claims and Litigation In the ordinary course of its insurance business, the Company has received and continues to receive claims for insurance arising under policies issued by the Company asserting alleged injuries and damages from asbestos- and environmental-related exposures that are the subject of related coverage litigation. The Company is defending asbestos- and environmental-related litigation vigorously and believes that it has meritorious defenses; however, the outcomes of these disputes are uncertain. In this regard, the Company employs dedicated specialists and comprehensive resolution strategies to manage asbestos and environmental loss exposure, including settling litigation under appropriate circumstances. Currently, it is not possible to predict legal outcomes and their impact on the future development of claims and litigation relating to asbestos and environmental claims. Any such development will be affected by future court decisions and interpretations, as well as changes in applicable legislation. Because of these uncertainties, additional liabilities may arise for amounts in excess of the Company’s current insurance reserves. In addition, the Company’s estimate of ultimate claims and claim adjustment expenses may change. These additional liabilities or changes in estimates, or a range of either, cannot now be reasonably estimated and could result in income statement charges that could be material to the Company’s results of operations in future periods. Other Proceedings Not Arising Under Insurance Contracts or Reinsurance Agreements The Company is involved in other lawsuits, including lawsuits alleging extra-contractual damages relating to insurance contracts or reinsurance agreements, that do not arise under insurance contracts or reinsurance agreements. The legal costs associated with such lawsuits are expensed in the period in which the costs are incurred. Based upon currently available information, the Company does not believe it is reasonably possible that any such lawsuit or related lawsuits would be material to the Company’s results of operations or would have a material adverse effect on the Company’s financial position or liquidity. Other Commitments and Guarantees Commitments Investment Commitments — The Company has unfunded commitments to private equity limited partnerships and real estate partnerships in which it invests. These commitments totaled $1.61 billion and $1.56 billion at March 31, 2018 and December 31, 2017 , respectively. Guarantees The maximum amount of the Company’s contingent obligation for indemnifications related to the sale of businesses that are quantifiable was $358 million at March 31, 2018 , of which $1 million was recognized on the balance sheet at that date. The maximum amount of the Company’s obligation for guarantees of certain investments and third-party loans related to certain investments that are quantifiable was $45 million at March 31, 2018 , approximately $23 million of which is indemnified by a third party. The maximum amount of the Company’s obligation related to the guarantee of certain insurance policy obligations of a former insurance subsidiary was $480 million at March 31, 2018 , all of which is indemnified by a third party. For more information regarding Company guarantees, see note 16 of notes to the consolidated financial statements in the Company’s 2017 Annual Report.

Consolidating Financial Stateme

Consolidating Financial Statements (Unaudited)	3 Months Ended
	Mar. 31, 2018
Consolidating Financial Statements of The Travelers Companies, Inc. and Subsidiaries (Unaudited) disclosure
Consolidating Financial Statements of The Travelers Companies, Inc. and Subsidiaries (Unaudited)	CONSOLIDATING FINANCIAL STATEMENTS OF THE TRAVELERS COMPANIES, INC. AND SUBSIDIARIES The following consolidating financial statements of the Company have been prepared pursuant to Rule 3-10 of Regulation S-X. These consolidating financial statements have been prepared from the Company’s financial information on the same basis of accounting as the consolidated financial statements. The Travelers Companies, Inc. (excluding its subsidiaries, TRV) has fully and unconditionally guaranteed certain debt obligations of Travelers Property Casualty Corp. (TPC) and Travelers Insurance Group Holdings, Inc. (TIGHI), which totaled $700 million at March 31, 2018 . Prior to the merger of TPC and The St. Paul Companies, Inc. in 2004, TPC fully and unconditionally guaranteed the payment of all principal, premiums, if any, and interest on certain debt obligations of its wholly-owned subsidiary, TIGHI. Concurrent with the merger, TRV fully and unconditionally assumed such guarantee obligations of TPC. TPC is deemed to have no assets or operations independent of TIGHI. Consolidating financial information for TIGHI has not been presented herein because such financial information would be substantially the same as the financial information provided for TPC. CONSOLIDATING STATEMENT OF INCOME (Unaudited) For the three months ended March 31, 2018 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Revenues Premiums $ 4,468 $ 2,069 $ — $ — $ 6,537 Net investment income 412 185 6 — 603 Fee income 103 — — — 103 Net realized investment gains (losses) (1) 2 (12 ) (1 ) — (11 ) Other revenues 27 28 — (1 ) 54 Total revenues 5,012 2,270 5 (1 ) 7,286 Claims and expenses Claims and claim adjustment expenses 2,910 1,386 — — 4,296 Amortization of deferred acquisition costs 705 356 — — 1,061 General and administrative expenses 729 328 6 (1 ) 1,062 Interest expense 11 — 78 — 89 Total claims and expenses 4,355 2,070 84 (1 ) 6,508 Income (loss) before income taxes 657 200 (79 ) — 778 Income tax expense (benefit) 106 32 (29 ) — 109 Net income of subsidiaries — — 719 (719 ) — Net income $ 551 $ 168 $ 669 $ (719 ) $ 669 ____________________________________________________ (1) Total other-than-temporary impairments (OTTI) for the three months ended March 31, 2018 , and the amounts comprising total OTTI that were recognized in net realized investment gains (losses) and in other comprehensive income (loss) (OCI) were as follows: (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Total OTTI losses $ — $ — $ — $ — $ — OTTI losses recognized in net realized investment gains (losses) $ — $ — $ — $ — $ — OTTI gains recognized in OCI $ — $ — $ — $ — $ — CONSOLIDATING STATEMENT OF INCOME (Unaudited) For the three months ended March 31, 2017 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Revenues Premiums $ 4,228 $ 1,955 $ — $ — $ 6,183 Net investment income 412 194 4 — 610 Fee income 113 — — — 113 Net realized investment gains (losses) (1) (4 ) 9 — — 5 Other revenues 24 9 — (2 ) 31 Total revenues 4,773 2,167 4 (2 ) 6,942 Claims and expenses Claims and claim adjustment expenses 2,752 1,342 — — 4,094 Amortization of deferred acquisition costs 668 335 — — 1,003 General and administrative expenses 703 292 3 (2 ) 996 Interest expense 12 — 77 — 89 Total claims and expenses 4,135 1,969 80 (2 ) 6,182 Income (loss) before income taxes 638 198 (76 ) — 760 Income tax expense (benefit) 130 54 (41 ) — 143 Net income of subsidiaries — — 652 (652 ) — Net income $ 508 $ 144 $ 617 $ (652 ) $ 617 _________________________________________________________ (1) Total other-than-temporary impairments (OTTI) for the three months ended March 31, 2017 , and the amounts comprising total OTTI that were recognized in net realized investment gains (losses) and in other comprehensive income (OCI) were as follows: (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Total OTTI losses $ — $ (1 ) $ — $ — $ (1 ) OTTI losses recognized in net realized investment gains (losses) $ (1 ) $ (1 ) $ — $ — $ (2 ) OTTI gains recognized in OCI $ 1 $ — $ — $ — $ 1 CONSOLIDATING STATEMENT OF COMPREHENSIVE INCOME (LOSS) (Unaudited) For the three months ended March 31, 2018 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Net income $ 551 $ 168 $ 669 $ (719 ) $ 669 Other comprehensive income (loss): Changes in net unrealized gains on investment securities: Having no credit losses recognized in the consolidated statement of income (838 ) (364 ) (1 ) — (1,203 ) Having credit losses recognized in the consolidated statement of income (1 ) (1 ) — — (2 ) Net changes in benefit plan assets and obligations — — 22 — 22 Net changes in unrealized foreign currency translation (25 ) 31 — — 6 Other comprehensive income (loss) before income taxes and other comprehensive loss of subsidiaries (864 ) (334 ) 21 — (1,177 ) Income tax expense (benefit) (175 ) (77 ) 8 — (244 ) Other comprehensive income (loss), net of taxes, before other comprehensive loss of subsidiaries (689 ) (257 ) 13 — (933 ) Other comprehensive loss of subsidiaries — — (946 ) 946 — Other comprehensive loss (689 ) (257 ) (933 ) 946 (933 ) Comprehensive loss $ (138 ) $ (89 ) $ (264 ) $ 227 $ (264 ) CONSOLIDATING STATEMENT OF COMPREHENSIVE INCOME (Unaudited) For the three months ended March 31, 2017 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Net income $ 508 $ 144 $ 617 $ (652 ) $ 617 Other comprehensive income: Changes in net unrealized gains on investment securities: Having no credit losses recognized in the consolidated statement of income 93 44 7 — 144 Having credit losses recognized in the consolidated statement of income 1 (1 ) — — — Net changes in benefit plan assets and obligations — — 17 — 17 Net changes in unrealized foreign currency translation 25 16 — — 41 Other comprehensive income before income taxes and other comprehensive income of subsidiaries 119 59 24 — 202 Income tax expense 37 16 9 — 62 Other comprehensive income, net of taxes, before other comprehensive income of subsidiaries 82 43 15 — 140 Other comprehensive income of subsidiaries — — 125 (125 ) — Other comprehensive income 82 43 140 (125 ) 140 Comprehensive income $ 590 $ 187 $ 757 $ (777 ) $ 757 CONSOLIDATING BALANCE SHEET (Unaudited) At March 31, 2018 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Assets Fixed maturities, available for sale, at fair value (amortized cost $62,093) $ 42,958 $ 19,225 $ 83 $ — $ 62,266 Equity securities, at fair value (cost $431) 147 103 180 — 430 Real estate investments 54 900 — — 954 Short-term securities 2,022 714 1,750 — 4,486 Other investments 2,745 842 1 — 3,588 Total investments 47,926 21,784 2,014 — 71,724 Cash 175 221 1 — 397 Investment income accrued 388 175 4 — 567 Premiums receivable 5,073 2,463 — — 7,536 Reinsurance recoverables 5,823 2,475 — — 8,298 Ceded unearned premiums 687 90 — — 777 Deferred acquisition costs 1,887 199 — — 2,086 Deferred taxes 115 271 (18 ) — 368 Contractholder receivables 3,907 928 — — 4,835 Goodwill 2,587 1,381 — (9 ) 3,959 Other intangible assets 201 140 — — 341 Investment in subsidiaries — — 27,090 (27,090 ) — Other assets 2,150 342 310 (14 ) 2,788 Total assets $ 70,919 $ 30,469 $ 29,401 $ (27,113 ) $ 103,676 Liabilities Claims and claim adjustment expense reserves $ 33,447 $ 16,363 $ — $ — $ 49,810 Unearned premium reserves 9,336 4,088 — — 13,424 Contractholder payables 3,907 928 — — 4,835 Payables for reinsurance premiums 295 203 — — 498 Debt 693 14 6,270 (14 ) 6,963 Other liabilities 3,922 1,091 154 — 5,167 Total liabilities 51,600 22,687 6,424 (14 ) 80,697 Shareholders’ equity Common stock (1,750.0 shares authorized; 270.3 shares issued and 270.2 shares outstanding) — 390 22,995 (390 ) 22,995 Additional paid-in capital 11,634 6,972 — (18,606 ) — Retained earnings 7,974 650 33,979 (8,622 ) 33,981 Accumulated other comprehensive loss (289 ) (230 ) (1,322 ) 519 (1,322 ) Treasury stock, at cost (503.7 shares) — — (32,675 ) — (32,675 ) Total shareholders’ equity 19,319 7,782 22,977 (27,099 ) 22,979 Total liabilities and shareholders’ equity $ 70,919 $ 30,469 $ 29,401 $ (27,113 ) $ 103,676 CONSOLIDATING BALANCE SHEET (Unaudited) At December 31, 2017 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Assets Fixed maturities, available for sale, at fair value (amortized cost $61,316) $ 43,240 $ 19,372 $ 82 $ — $ 62,694 Equity securities, available for sale, at fair value (cost $440) 161 111 181 — 453 Real estate investments 54 878 — — 932 Short-term securities 2,751 914 1,230 — 4,895 Other investments 2,673 854 1 — 3,528 Total investments 48,879 22,129 1,494 — 72,502 Cash 157 187 — — 344 Investment income accrued 418 183 5 — 606 Premiums receivable 4,852 2,292 — — 7,144 Reinsurance recoverables 5,842 2,467 — — 8,309 Ceded unearned premiums 493 58 — — 551 Deferred acquisition costs 1,835 190 — — 2,025 Deferred taxes (89 ) 173 (14 ) — 70 Contractholder receivables 3,854 921 — — 4,775 Goodwill 2,592 1,368 — (9 ) 3,951 Other intangible assets 202 140 — — 342 Investment in subsidiaries — — 27,946 (27,946 ) — Other assets 2,181 (3 ) 700 (14 ) 2,864 Total assets $ 71,216 $ 30,105 $ 30,131 $ (27,969 ) $ 103,483 Liabilities Claims and claim adjustment expense reserves $ 33,386 $ 16,264 $ — $ — $ 49,650 Unearned premium reserves 8,957 3,958 — — 12,915 Contractholder payables 3,854 921 — — 4,775 Payables for reinsurance premiums 165 109 — — 274 Debt 693 14 5,878 (14 ) 6,571 Other liabilities 4,161 882 524 — 5,567 Total liabilities 51,216 22,148 6,402 (14 ) 79,752 Shareholders’ equity Common stock (1,750.0 shares authorized; 271.5 shares issued and 271.4 shares outstanding) — 390 22,886 (390 ) 22,886 Additional paid-in capital 11,634 6,972 — (18,606 ) — Retained earnings 8,036 594 33,460 (8,628 ) 33,462 Accumulated other comprehensive income (loss) 330 1 (343 ) (331 ) (343 ) Treasury stock, at cost (500.9 shares) — — (32,274 ) — (32,274 ) Total shareholders’ equity 20,000 7,957 23,729 (27,955 ) 23,731 Total liabilities and shareholders’ equity $ 71,216 $ 30,105 $ 30,131 $ (27,969 ) $ 103,483 CONSOLIDATING STATEMENT OF CASH FLOWS (Unaudited) For the three months ended March 31, 2018 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Cash flows from operating activities Net income $ 551 $ 168 $ 669 $ (719 ) $ 669 Net adjustments to reconcile net income to net cash provided by operating activities (126 ) (57 ) (22 ) 90 (115 ) Net cash provided by operating activities 425 111 647 (629 ) 554 Cash flows from investing activities Proceeds from maturities of fixed maturities 1,453 493 4 — 1,950 Proceeds from sales of investments: Fixed maturities 729 356 — — 1,085 Equity securities 8 18 — — 26 Real estate investments — — — — — Other investments 76 38 — — 114 Purchases of investments: Fixed maturities (2,836 ) (1,078 ) (6 ) — (3,920 ) Equity securities (1 ) (18 ) (1 ) — (20 ) Real estate investments — (33 ) — — (33 ) Other investments (115 ) (27 ) — — (142 ) Net sales (purchases) of short-term securities 729 201 (520 ) — 410 Securities transactions in course of settlement 147 56 (1 ) — 202 Other (52 ) (1 ) — — (53 ) Net cash provided by (used in) investing activities 138 5 (524 ) — (381 ) Cash flows from financing activities Treasury stock acquired — share repurchase authorization — — (350 ) — (350 ) Treasury stock acquired — net employee share-based compensation — — (51 ) — (51 ) Dividends paid to shareholders — — (197 ) — (197 ) Payment of debt — — (100 ) — (100 ) Issuance of debt — — 491 — 491 Issuance of common stock — employee share options — — 85 — 85 Dividends paid to parent company (544 ) (85 ) — 629 — Net cash used in financing activities (544 ) (85 ) (122 ) 629 (122 ) Effect of exchange rate changes on cash (1 ) 3 — — 2 Net increase in cash 18 34 1 — 53 Cash at beginning of year 157 187 — — 344 Cash at end of period $ 175 $ 221 $ 1 $ — $ 397 Supplemental disclosure of cash flow information Income taxes paid $ 13 $ 43 $ — $ — $ 56 Interest paid $ 16 $ — $ 23 $ — $ 39 CONSOLIDATING STATEMENT OF CASH FLOWS (Unaudited) For the three months ended March 31, 2017 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Cash flows from operating activities Net income $ 508 $ 144 $ 617 $ (652 ) $ 617 Net adjustments to reconcile net income to net cash provided by operating activities 160 9 205 (143 ) 231 Net cash provided by operating activities 668 153 822 (795 ) 848 Cash flows from investing activities Proceeds from maturities of fixed maturities 1,638 580 — — 2,218 Proceeds from sales of investments: Fixed maturities 88 100 — — 188 Equity securities 2 19 — — 21 Real estate investments — 11 — — 11 Other investments 96 26 — — 122 Purchases of investments: Fixed maturities (2,191 ) (864 ) (1 ) — (3,056 ) Equity securities (1 ) (20 ) (1 ) — (22 ) Real estate investments — (16 ) — — (16 ) Other investments (96 ) (28 ) — — (124 ) Net sales (purchases) of short-term securities 245 233 (429 ) — 49 Securities transactions in course of settlement 102 53 2 — 157 Other (70 ) 7 — — (63 ) Net cash provided by (used in) investing activities (187 ) 101 (429 ) — (515 ) Cash flows from financing activities Treasury stock acquired — share repurchase authorization — — (225 ) — (225 ) Treasury stock acquired — net employee share-based compensation — — (61 ) — (61 ) Dividends paid to shareholders — — (190 ) — (190 ) Issuance of common stock — employee share options — — 83 — 83 Dividends paid to parent company (532 ) (263 ) — 795 — Net cash used in financing activities (532 ) (263 ) (393 ) 795 (393 ) Effect of exchange rate changes on cash 1 1 — — 2 Net decrease in cash (50 ) (8 ) — — (58 ) Cash at beginning of year 141 164 2 — 307 Cash at end of period $ 91 $ 156 $ 2 $ — $ 249 Supplemental disclosure of cash flow information Income taxes paid $ 1 $ 1 $ — $ — $ 2 Interest paid $ 16 $ — $ 27 $ — $ 43

Basis of Presentation and Acc23

Basis of Presentation and Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accounting Policies, Basis of Presentation [Policy Text Block]	Basis of Presentation The interim consolidated financial statements include the accounts of The Travelers Companies, Inc. (together with its subsidiaries, the Company). These financial statements are prepared in conformity with U.S. generally accepted accounting principles (GAAP) and are unaudited. In the opinion of the Company’s management, all adjustments necessary for a fair presentation have been reflected. Certain financial information that is normally included in annual financial statements prepared in accordance with GAAP, but that is not required for interim reporting purposes, has been omitted. All material intercompany transactions and balances have been eliminated. The accompanying interim consolidated financial statements and related notes should be read in conjunction with the Company’s consolidated financial statements and related notes included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2017 (the Company’s 2017 Annual Report). The preparation of the interim consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the interim consolidated financial statements and the reported amounts of revenues and claims and expenses during the reporting period. Actual results could differ from those estimates. Certain reclassifications have been made to the 2017 financial statements to conform to the 2018 presentation.
Accounting Policies, Adoption of Accounting Standards [Policy Text Block]	Adoption of Accounting Standards Financial Instruments: Recognition and Measurement of Financial Assets and Financial Liabilities In January 2016, the Financial Accounting Standards Board (FASB) issued updated guidance to address the recognition, measurement, presentation and disclosure of certain financial instruments. The updated guidance requires equity investments, except those accounted for under the equity method of accounting, that have readily determinable fair value to be measured at fair value with any changes in fair value recognized in net income. Equity securities that do not have readily determinable fair values may be measured at estimated fair value or cost less impairment, if any, adjusted for subsequent observable price changes, with changes in the carrying value recognized in net income. A qualitative assessment for impairment is required for equity investments without readily determinable fair values. The updated guidance also eliminates the requirement to disclose the method and significant assumptions used to estimate the fair value of financial instruments measured at amortized cost on the balance sheet. The updated guidance was effective for the quarter ended March 31, 2018. The adoption of this guidance resulted in the recognition of $22 million of net after-tax unrealized gains on equity investments as a cumulative effect adjustment that increased retained earnings as of January 1, 2018 and decreased accumulated other comprehensive income (AOCI) by the same amount. The Company elected to report changes in the fair value of equity investments in net realized investment gains (losses). At December 31, 2017, equity investments were classified as available-for-sale on the Company's balance sheet. However, upon adoption, the updated guidance eliminated the available-for-sale balance sheet classification for equity investments. Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income On February 14, 2018, the FASB issued updated guidance that allows a reclassification from AOCI to retained earnings of the stranded tax effects that occurred due to the enactment of the Tax Cuts and Jobs Act of 2017 (TCJA). The updated guidance is effective for reporting periods beginning after December 15, 2018 and is to be applied retrospectively to each period in which there are items impacted by the TCJA remaining in AOCI or at the beginning of the period of adoption. Early adoption is permitted. The Company adopted the updated guidance effective January 1, 2018 and elected to reclassify the income tax effects of the TCJA from AOCI to retained earnings as of January 1, 2018. This reclassification resulted in an increase in retained earnings of $24 million as of January 1, 2018 and a decrease in AOCI by the same amount. Revenue from Contracts with Customers In May 2014, the FASB issued updated guidance to clarify the principles for recognizing revenue. The updated guidance was effective for reporting periods beginning after December 15, 2017, and requires an entity to recognize revenue as performance obligations are met, in order to reflect the transfer of goods or services to customers in an amount that reflects the consideration the entity is entitled to receive for those goods or services. For the three months ended March 31, 2018, approximately $40 million , or less than 1% of the Company's total revenues, were within the scope of this updated guidance and were generated from the services described below. While insurance contracts are not within the scope of this updated guidance, the Company’s revenue related to certain services with no underlying insurance risk is subject to the updated guidance. These services include the following: (i) insurance-related services, such as risk management services, claims administration, loss control and risk management information services on behalf of non-insureds; (ii) servicing carrier fees for various residual market pools and associations; and (iii) administrative fees related to servicing third-party insurers’ obligations to participate in the Workers' Compensation Residual Market Plans in certain states. The revenues earned from these service contracts were not impacted by the adoption of the updated guidance. These revenues are earned on a pro rata basis over the contract service period and reported in fee income in the Company’s consolidated statement of income. Commissions earned from on-line insurance brokerage services are also subject to this updated guidance and were also not impacted by the adoption of the updated guidance. Commissions are earned upon collection of the gross premium in accordance with the contracts and an accrual is made to recognize policy cancellations, either at the policyholder’s direction or for non-payment. Commissions are reported in other revenues in the Company's consolidated statement of income. The Company does not capitalize the costs to obtain or fulfill the contracts for which revenues are reported in fee income and other income, and has not recognized any impairment losses on the receivables related to these contracts during the three months ended March 31, 2018. The Company adopted the updated guidance effective January 1, 2018. The adoption did not have an effect on the Company’s results of operations, financial position or liquidity. Statement of Cash Flows: Classification of Certain Cash Receipts and Cash Payments In August 2016, the FASB issued updated guidance on the classification of cash flows related to certain activities in the statement of cash flows to reduce diversity in practice. The updated guidance was effective for reporting periods beginning after December 15, 2017 and was applied retrospectively to all periods presented. Under the new guidance, distributions received on equity method investments that are considered to be a return on investment are reported as cash flows from operating activities. These distributions were previously reported as cash flows from investing activities. The adoption of this guidance had no effect on the Company’s results of operations, financial position or liquidity. For information regarding accounting standards that the Company adopted during the years presented, see the “Adoption of Accounting Standards ” section of note 1 of notes to the consolidated financial statements in the Company’s 2017 Annual Report.

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2018
Segment Reporting [Abstract]
Company's revenues and income by segment [Table Text Block]	The following tables summarize the components of the Company’s revenues, income and total assets by reportable business segments: (For the three months ended March 31, in millions) Business Insurance Bond & Specialty Insurance Personal Insurance Total Reportable Segments 2018 Premiums $ 3,568 $ 582 $ 2,387 $ 6,537 Net investment income 446 58 99 603 Fee income 99 — 4 103 Other revenues 31 6 17 54 Total segment revenues (1) $ 4,144 $ 646 $ 2,507 $ 7,297 Segment income (1) $ 452 $ 173 $ 129 $ 754 2017 Premiums $ 3,429 $ 555 $ 2,199 $ 6,183 Net investment income 453 61 96 610 Fee income 109 — 4 113 Other revenues 9 5 16 30 Total segment revenues (1) $ 4,000 $ 621 $ 2,315 $ 6,936 Segment income (1) $ 442 $ 145 $ 89 $ 676 _________________________________________________________ (1) Segment revenues for reportable business segments exclude net realized investment gains (losses). Segment income for reportable business segments equals net income excluding the after-tax impact of net realized investment gains (losses).
Business segment reconciliations of revenue and income, net of tax [Table Text Block]	Three Months Ended (in millions) 2018 2017 Revenue reconciliation Earned premiums Business Insurance: Domestic: Workers’ compensation $ 971 $ 976 Commercial automobile 562 506 Commercial property 438 435 General liability 521 491 Commercial multi-peril 805 774 Other 7 7 Total Domestic 3,304 3,189 International 264 240 Total Business Insurance 3,568 3,429 Bond & Specialty Insurance: Domestic: Fidelity and surety 246 234 General liability 242 235 Other 47 45 Total Domestic 535 514 International 47 41 Total Bond & Specialty Insurance 582 555 Personal Insurance: Domestic: Automobile 1,225 1,094 Homeowners and Other 995 955 Total Domestic 2,220 2,049 International 167 150 Total Personal Insurance 2,387 2,199 Total earned premiums 6,537 6,183 Net investment income 603 610 Fee income 103 113 Other revenues 54 30 Total segment revenues 7,297 6,936 Other revenues — 1 Net realized investment gains (losses) (11 ) 5 Total revenues $ 7,286 $ 6,942 Income reconciliation, net of tax Total segment income $ 754 $ 676 Interest Expense and Other (1) (76 ) (62 ) Core income 678 614 Net realized investment gains (losses) (9 ) 3 Net income $ 669 $ 617 _________________________________________________________ (1) The primary component of Interest Expense and Other was after-tax interest expense of $70 million and $58 million in the three months ended March 31, 2018 and 2017 , respectively.
Asset reconciliation [Table Text Block]	(in millions) March 31, December 31, Asset reconciliation Business Insurance $ 78,747 $ 78,082 Bond & Specialty Insurance 8,787 8,776 Personal Insurance 15,605 15,949 Total segment assets 103,139 102,807 Other assets (1) 537 676 Total consolidated assets $ 103,676 $ 103,483 _________________________________________________________ (1) The primary components of other assets at March 31, 2018 were accrued over-funded benefit plan assets related to the Company’s qualified domestic pension plan and other intangible assets, and the primary components at December 31, 2017 were accrued over-funded benefit plan assets related to the Company’s qualified domestic pension plan, other intangible assets and deferred taxes.

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2018
Investments [Abstract]
Amortized cost and fair value of investments in fixed maturities [Table Text Block]	The amortized cost and fair value of investments in fixed maturities classified as available for sale were as follows: Amortized Gross Unrealized Fair (at March 31, 2018, in millions) Cost Gains Losses Value U.S. Treasury securities and obligations of U.S. government and government agencies and authorities $ 2,051 $ 2 $ 19 $ 2,034 Obligations of states, municipalities and political subdivisions: Local general obligation 13,593 215 127 13,681 Revenue 10,512 177 91 10,598 State general obligation 1,391 21 12 1,400 Pre-refunded 3,638 123 — 3,761 Total obligations of states, municipalities and political subdivisions 29,134 536 230 29,440 Debt securities issued by foreign governments 1,326 9 8 1,327 Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 2,495 76 40 2,531 All other corporate bonds 27,000 231 389 26,842 Redeemable preferred stock 87 5 — 92 Total $ 62,093 $ 859 $ 686 $ 62,266 Amortized Gross Unrealized Fair (at December 31, 2017, in millions) Cost Gains Losses Value U.S. Treasury securities and obligations of U.S. government and government agencies and authorities $ 2,080 $ 4 $ 8 $ 2,076 Obligations of states, municipalities and political subdivisions: Local general obligation 13,488 444 26 13,906 Revenue 11,307 338 19 11,626 State general obligation 1,443 44 3 1,484 Pre-refunded 3,758 142 1 3,899 Total obligations of states, municipalities and political subdivisions 29,996 968 49 30,915 Debt securities issued by foreign governments 1,505 14 10 1,509 Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 2,334 87 11 2,410 All other corporate bonds 25,311 478 100 25,689 Redeemable preferred stock 90 5 — 95 Total $ 61,316 $ 1,556 $ 178 $ 62,694
Cost and fair value of investments in equity securities [Table Text Block]	Fair (at March 31, 2018, in millions) Cost Gross Gains Gross Losses Value Public common stock $ 330 $ 4 $ 10 $ 324 Non-redeemable preferred stock 101 11 6 106 Total $ 431 $ 15 $ 16 $ 430
Cost and fair value of investments in equity securities classified as available for sale [Table Text Block]	Fair (at December 31, 2017, in millions) Cost Gross Gains Gross Losses Value Public common stock $ 332 $ 8 $ 1 $ 339 Non-redeemable preferred stock 108 12 6 114 Total $ 440 $ 20 $ 7 $ 453
Unrealized investment losses [Table Text Block]	The following tables summarize, for all investments in an unrealized loss position at March 31, 2018 and December 31, 2017 , the aggregate fair value and gross unrealized loss by length of time those securities have been continuously in an unrealized loss position. The fair value amounts reported in the tables are estimates that are prepared using the process described in note 4 herein and in note 4 of notes to the consolidated financial statements in the Company’s 2017 Annual Report. The Company also relies upon estimates of several factors in its review and evaluation of individual investments, using the process described in note 1 of notes to the consolidated financial statements in the Company’s 2017 Annual Report in determining whether such investments are other-than-temporarily impaired. Less than 12 months 12 months or longer Total (at March 31, 2018, in millions) Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fair Value Gross Unrealized Losses Fixed maturities U.S. Treasury securities and obligations of U.S. government and government agencies and authorities $ 1,332 $ 15 $ 549 $ 4 $ 1,881 $ 19 Obligations of states, municipalities and political subdivisions 5,823 94 2,863 136 8,686 230 Debt securities issued by foreign governments 431 7 32 1 463 8 Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 1,474 32 235 8 1,709 40 All other corporate bonds 14,816 294 1,910 95 16,726 389 Total fixed maturities $ 23,876 $ 442 $ 5,589 $ 244 $ 29,465 $ 686 Less than 12 months 12 months or Total (at December 31, 2017, in millions) Fair Gross Fair Gross Fair Gross Unrealized Losses Fixed maturities U.S. Treasury securities and obligations of U.S. government and government agencies and authorities $ 1,150 $ 5 $ 470 $ 3 $ 1,620 $ 8 Obligations of states, municipalities and political subdivisions 505 2 2,959 47 3,464 49 Debt securities issued by foreign governments 394 6 111 4 505 10 Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 1,021 7 250 4 1,271 11 All other corporate bonds 6,062 48 1,990 52 8,052 100 Total fixed maturities 9,132 68 5,780 110 14,912 178 Equity securities Public common stock 18 — 34 1 52 1 Non-redeemable preferred stock 3 — 56 6 59 6 Total equity securities 21 — 90 7 111 7 Total $ 9,153 $ 68 $ 5,870 $ 117 $ 15,023 $ 185

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities reported at fair value are measured on a recurring basis [Table Text Block]	The following tables present the level within the fair value hierarchy at which the Company’s financial assets and financial liabilities are measured on a recurring basis. An investment transferred between levels during a period is transferred at its fair value as of the beginning of that period. (at March 31, 2018, in millions) Total Level 1 Level 2 Level 3 Invested assets: Fixed maturities U.S. Treasury securities and obligations of U.S. government and government agencies and authorities $ 2,034 $ 2,034 $ — $ — Obligations of states, municipalities and political subdivisions 29,440 — 29,428 12 Debt securities issued by foreign governments 1,327 — 1,327 — Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 2,531 — 2,491 40 All other corporate bonds 26,842 1 26,646 195 Redeemable preferred stock 92 3 89 — Total fixed maturities 62,266 2,038 59,981 247 Equity securities Public common stock 324 324 — — Non-redeemable preferred stock 106 42 64 — Total equity securities 430 366 64 — Other investments 55 17 — 38 Total $ 62,751 $ 2,421 $ 60,045 $ 285 (at December 31, 2017, in millions) Total Level 1 Level 2 Level 3 Invested assets: Fixed maturities U.S. Treasury securities and obligations of U.S. government and government agencies and authorities $ 2,076 $ 2,076 $ — $ — Obligations of states, municipalities and political subdivisions 30,915 — 30,910 5 Debt securities issued by foreign governments 1,509 — 1,509 — Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 2,410 — 2,371 39 All other corporate bonds 25,689 11 25,518 160 Redeemable preferred stock 95 3 92 — Total fixed maturities 62,694 2,090 60,400 204 Equity securities Public common stock 339 339 — — Non-redeemable preferred stock 114 45 69 — Total equity securities 453 384 69 — Other investments 57 19 — 38 Total $ 63,204 $ 2,493 $ 60,469 $ 242
Carrying value and fair value of financial instruments disclosed, but not carried, at fair value and the level within the fair value hierarchy at which such financial instruments are categorized [Table Text Block]	The following tables present the carrying value and fair value of the Company’s financial assets and financial liabilities disclosed, but not carried, at fair value, and the level within the fair value hierarchy at which such assets and liabilities are categorized. (at March 31, 2018, in millions) Carrying Value Fair Value Level 1 Level 2 Level 3 Financial assets: Short-term securities $ 4,486 $ 4,486 $ 835 $ 3,612 $ 39 Financial liabilities: Debt $ 6,963 $ 7,835 $ — $ 7,835 $ — (at December 31, 2017, in millions) Carrying Value Fair Value Level 1 Level 2 Level 3 Financial assets: Short-term securities $ 4,895 $ 4,895 $ 1,238 $ 3,622 $ 35 Financial liabilities: Debt $ 6,471 $ 7,702 $ — $ 7,702 $ — Commercial paper $ 100 $ 100 $ — $ 100 $ —

Goodwill and Other Intangible27

Goodwill and Other Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill by segment [Table Text Block]	The following table presents the carrying amount of the Company’s goodwill by segment. Each reportable segment includes goodwill associated with the Company’s international business which is subject to the impact of changes in foreign currency exchange rates. (in millions) March 31, December 31, Business Insurance $ 2,597 $ 2,585 Bond & Specialty Insurance 550 550 Personal Insurance 786 790 Other 26 26 Total $ 3,959 $ 3,951
Other intangible assets subject to amortization [Table Text Block]	Other Intangible Assets The following tables present a summary of the Company’s other intangible assets by major asset class. (at March 31, 2018, in millions) Gross Carrying Amount Accumulated Amortization Net Subject to amortization Customer-related $ 80 $ 5 $ 75 Contract-based (1) 209 170 39 Total subject to amortization 289 175 114 Not subject to amortization 227 — 227 Total $ 516 $ 175 $ 341 (at December 31, 2017, in millions) Gross Carrying Amount Accumulated Amortization Net Subject to amortization Customer-related $ 77 $ 4 $ 73 Contract-based (1) 209 167 42 Total subject to amortization 286 171 115 Not subject to amortization 227 — 227 Total $ 513 $ 171 $ 342 _________________________________________________________ (1) Contract-based intangible assets subject to amortization are comprised of fair value adjustments on claims and claim adjustment expense reserves, reinsurance recoverables and other contract-related intangible assets. Fair value adjustments recorded in connection with insurance acquisitions were based on management’s estimate of nominal claims and claim adjustment expense reserves and reinsurance recoverables. The method used calculated a risk adjustment to a risk-free discounted reserve that would, if reserves ran off as expected, produce results that yielded the assumed cost-of-capital on the capital supporting the loss reserves. The fair value adjustments are reported as other intangible assets on the consolidated balance sheet, and the amounts measured in accordance with the acquirer’s accounting policies for insurance contracts have been reported as part of the claims and claim adjustment expense reserves and reinsurance recoverables. The intangible assets are being recognized into income over the expected payment pattern. Because the time value of money and the risk adjustment (cost of capital) components of the intangible assets run off at different rates, the amount recognized in income may be a net benefit in some periods and a net expense in other periods.
Other intangible assets not subject to amortization [Table Text Block]	Other Intangible Assets The following tables present a summary of the Company’s other intangible assets by major asset class. (at March 31, 2018, in millions) Gross Carrying Amount Accumulated Amortization Net Subject to amortization Customer-related $ 80 $ 5 $ 75 Contract-based (1) 209 170 39 Total subject to amortization 289 175 114 Not subject to amortization 227 — 227 Total $ 516 $ 175 $ 341 (at December 31, 2017, in millions) Gross Carrying Amount Accumulated Amortization Net Subject to amortization Customer-related $ 77 $ 4 $ 73 Contract-based (1) 209 167 42 Total subject to amortization 286 171 115 Not subject to amortization 227 — 227 Total $ 513 $ 171 $ 342 _________________________________________________________ (1) Contract-based intangible assets subject to amortization are comprised of fair value adjustments on claims and claim adjustment expense reserves, reinsurance recoverables and other contract-related intangible assets. Fair value adjustments recorded in connection with insurance acquisitions were based on management’s estimate of nominal claims and claim adjustment expense reserves and reinsurance recoverables. The method used calculated a risk adjustment to a risk-free discounted reserve that would, if reserves ran off as expected, produce results that yielded the assumed cost-of-capital on the capital supporting the loss reserves. The fair value adjustments are reported as other intangible assets on the consolidated balance sheet, and the amounts measured in accordance with the acquirer’s accounting policies for insurance contracts have been reported as part of the claims and claim adjustment expense reserves and reinsurance recoverables. The intangible assets are being recognized into income over the expected payment pattern. Because the time value of money and the risk adjustment (cost of capital) components of the intangible assets run off at different rates, the amount recognized in income may be a net benefit in some periods and a net expense in other periods.

Insurance Claim Reserves (Table

Insurance Claim Reserves (Tables)	3 Months Ended
	Mar. 31, 2018
Insurance Loss Reserves [Abstract]
Claims and claim adjustment expense reserves [Table Text Block]	Claims and claim adjustment expense reserves were as follows: (in millions) March 31, December 31, Property-casualty $ 49,794 $ 49,633 Accident and health 16 17 Total $ 49,810 $ 49,650
Reconciliation of beginning and ending property casualty reserve balances for claims and claim adjustment expenses [Table Text Block]	The following table presents a reconciliation of beginning and ending property casualty reserve balances for claims and claim adjustment expenses for the three months ended March 31, 2018 and 2017 : (for the three months ended March 31, in millions) 2018 2017 Claims and claim adjustment expense reserves at beginning of year $ 49,633 $ 47,929 Less reinsurance recoverables on unpaid losses 8,123 7,981 Net reserves at beginning of year 41,510 39,948 Estimated claims and claim adjustment expenses for claims arising in the current year 4,391 4,126 Estimated decrease in claims and claim adjustment expenses for claims arising in prior years (116 ) (50 ) Total increases 4,275 4,076 Claims and claim adjustment expense payments for claims arising in: Current year 1,009 887 Prior years 3,040 2,812 Total payments 4,049 3,699 Unrealized foreign exchange (gain) loss (10 ) 34 Net reserves at end of period 41,726 40,359 Plus reinsurance recoverables on unpaid losses 8,068 7,942 Claims and claim adjustment expense reserves at end of period $ 49,794 $ 48,301

Other Comprehensive Income an29

Other Comprehensive Income and Accumulated Other Comprehensive Income (Tables)	3 Months Ended
	Mar. 31, 2018
Other Comprehensive Income and Accumulated Other Comprehensive Income disclosure
Changes in accumulated other comprehensive income (loss) (AOCI) [Table Text Block]	The following table presents the changes in the Company’s accumulated other comprehensive income (loss) (AOCI) for the three months ended March 31, 2018 . Changes in Net Unrealized Gains on Investment Securities (in millions) Having No Credit Losses Recognized in the Consolidated Statement of Income Having Credit Losses Recognized in the Consolidated Statement of Income Net Benefit Plan Assets and Obligations Recognized in Shareholders’ Equity Net Unrealized Foreign Currency Translation Total Accumulated Other Comprehensive Income (Loss) Balance, December 31, 2017 $ 747 $ 207 $ (686 ) $ (611 ) $ (343 ) Cumulative effect of adoption of updated accounting guidance for equity financial instruments at January 1, 2018 (34 ) — — — (34 ) Income tax benefit (12 ) — — — (12 ) Net of income taxes (22 ) — — — (22 ) Reclassification of certain tax effects from accumulated other comprehensive income at January 1, 2018 145 7 (141 ) (35 ) (24 ) Total effect of adoption of new guidance at January 1, 2018, net of tax 123 7 (141 ) (35 ) (46 ) Other comprehensive income (loss) (OCI) before reclassifications, net of tax (950 ) (1 ) — 1 (950 ) Amounts reclassified from AOCI, net of tax — — 17 — 17 Net OCI, current period (950 ) (1 ) 17 1 (933 ) Balance, March 31, 2018 $ (80 ) $ 213 $ (810 ) $ (645 ) $ (1,322 )
Pre-tax components of other comprehensive income (loss) and the related income tax expense (benefit) for each component [Table Text Block]	The following table presents the pre-tax components of the Company’s other comprehensive income (loss) and the related income tax expense (benefit). Three Months Ended (in millions) 2018 2017 Changes in net unrealized gains on investment securities: Having no credit losses recognized in the consolidated statement of income $ (1,203 ) $ 144 Income tax expense (benefit) (253 ) 51 Net of taxes (950 ) 93 Having credit losses recognized in the consolidated statement of income (2 ) — Income tax benefit (1 ) — Net of taxes (1 ) — Net changes in benefit plan assets and obligations 22 17 Income tax expense 5 5 Net of taxes 17 12 Net changes in unrealized foreign currency translation 6 41 Income tax expense 5 6 Net of taxes 1 35 Total other comprehensive income (loss) (1,177 ) 202 Total income tax expense (benefit) (244 ) 62 Total other comprehensive income (loss), net of taxes $ (933 ) $ 140
Pre-tax and related income tax (expense) benefit components of the amounts reclassified from accumulated other comprehensive income to the consolidated statement of income [Table Text Block]	The following table presents the pre-tax and related income tax (expense) benefit components of the amounts reclassified from the Company’s AOCI to the Company’s consolidated statement of income. Three Months Ended (in millions) 2018 2017 Reclassification adjustments related to unrealized gains on investment securities: Having no credit losses recognized in the consolidated statement of income (1) $ — $ (10 ) Income tax expense (2) — (3 ) Net of taxes — (7 ) Having credit losses recognized in the consolidated statement of income (1) — — Income tax benefit (2) — — Net of taxes — — Reclassification adjustment related to benefit plan assets and obligations: Claims and claim adjustment expenses (3) 9 7 General and administrative expenses (3) 13 10 Total 22 17 Income tax benefit (2) 5 5 Net of taxes 17 12 Reclassification adjustment related to foreign currency translation (1) — — Income tax benefit (2) — — Net of taxes — — Total reclassifications 22 7 Total income tax benefit 5 2 Total reclassifications, net of taxes $ 17 $ 5 _________________________________________________________ (1) (Increases) decreases net realized investment gains (losses) on the consolidated statement of income. (2) (Increases) decreases income tax expense on the consolidated statement of income. (3) Increases (decreases) expenses on the consolidated statement of income.

Earnings per Share (Table)

Earnings per Share (Table)	3 Months Ended
	Mar. 31, 2018
Earnings Per Share Reconciliation [Abstract]
Earnings per share reconciliation [Table Text Block]	The following is a reconciliation of the net income and share data used in the basic and diluted earnings per share computations for the periods presented: Three Months Ended (in millions, except per share amounts) 2018 2017 Basic and Diluted Net income, as reported $ 669 $ 617 Participating share-based awards — allocated income (5 ) (4 ) Net income available to common shareholders — basic and diluted $ 664 $ 613 Common Shares Basic Weighted average shares outstanding 271.0 279.7 Diluted Weighted average shares outstanding 271.0 279.7 Weighted average effects of dilutive securities — stock options and performance shares 2.9 2.7 Total 273.9 282.4 Net Income per Common Share Basic $ 2.45 $ 2.19 Diluted $ 2.42 $ 2.17

Share-Based Incentive Compens31

Share-Based Incentive Compensation (Table)	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Information for fully vested stock option awards [Table Text Block]	The following information relates to fully vested stock option awards at March 31, 2018 : Stock Options Number Weighted Average Exercise Price Weighted Average Contractual Life Remaining Aggregate Intrinsic Value ($ in millions) Vested at end of period (1) 6,207,090 $ 98.23 6.6 years $ 253 Exercisable at end of period 3,696,007 $ 84.13 5.2 years $ 202 _________________________________________________________ (1) Represents awards for which the requisite service has been rendered, including those that are retirement eligible.

Pension Plans, Retirement Ben32

Pension Plans, Retirement Benefits and Savings Plans (Tables)	3 Months Ended
	Mar. 31, 2018
Retirement Benefits [Abstract]
Summary of the components of net periodic benefit cost for the Company's pension and postretirement benefit plans recognized in the consolidated statement of income [Table Text Block]	The following table summarizes the components of net periodic benefit cost for the Company’s pension and postretirement benefit plans recognized in the consolidated statement of income for the three months ended March 31, 2018 and 2017 . Pension Plans Postretirement Benefit Plans (for the three months ended March 31, in millions) 2018 2017 2018 2017 Net Periodic Benefit Cost: Service cost $ 33 $ 30 $ — $ — Non-service cost: Interest cost on benefit obligation 31 31 2 2 Expected return on plan assets (66 ) (60 ) — — Amortization of unrecognized: Prior service benefit — — (1 ) (1 ) Net actuarial loss 23 18 — — Total non-service cost (benefit) (12 ) (11 ) 1 1 Net periodic benefit cost $ 21 $ 19 $ 1 $ 1
Consolidated statement of income line items impacted by service costs and non-service benefit costs [Table Text Block]	The following table indicates the line items in which the respective service costs and non-service benefit costs are presented in the consolidated statement of income for the three months ended March 31, 2018 and 2017 . Pension Plans Postretirement Benefit Plans (for the three months ended March 31, in millions) 2018 2017 2018 2017 Service Cost: Claims and claim adjustment expenses $ 13 $ 12 $ — $ — General and administrative expenses 20 18 — — Total service cost 33 30 — — Non-Service Cost: Claims and claim adjustment expenses (5 ) (4 ) — — General and administrative expenses (7 ) (7 ) 1 1 Total non-service cost (benefit) (12 ) (11 ) 1 1 Net periodic benefit cost $ 21 $ 19 $ 1 $ 1

Consolidating Financial State33

Consolidating Financial Statements (Unaudited) (Tables)	3 Months Ended
	Mar. 31, 2018
Consolidating Financial Statements of The Travelers Companies, Inc. and Subsidiaries (Unaudited) disclosure
Consolidating Statement of Income (Unaudited) [Table Text Block]	CONSOLIDATING STATEMENT OF INCOME (Unaudited) For the three months ended March 31, 2018 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Revenues Premiums $ 4,468 $ 2,069 $ — $ — $ 6,537 Net investment income 412 185 6 — 603 Fee income 103 — — — 103 Net realized investment gains (losses) (1) 2 (12 ) (1 ) — (11 ) Other revenues 27 28 — (1 ) 54 Total revenues 5,012 2,270 5 (1 ) 7,286 Claims and expenses Claims and claim adjustment expenses 2,910 1,386 — — 4,296 Amortization of deferred acquisition costs 705 356 — — 1,061 General and administrative expenses 729 328 6 (1 ) 1,062 Interest expense 11 — 78 — 89 Total claims and expenses 4,355 2,070 84 (1 ) 6,508 Income (loss) before income taxes 657 200 (79 ) — 778 Income tax expense (benefit) 106 32 (29 ) — 109 Net income of subsidiaries — — 719 (719 ) — Net income $ 551 $ 168 $ 669 $ (719 ) $ 669 ____________________________________________________ (1) Total other-than-temporary impairments (OTTI) for the three months ended March 31, 2018 , and the amounts comprising total OTTI that were recognized in net realized investment gains (losses) and in other comprehensive income (loss) (OCI) were as follows: (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Total OTTI losses $ — $ — $ — $ — $ — OTTI losses recognized in net realized investment gains (losses) $ — $ — $ — $ — $ — OTTI gains recognized in OCI $ — $ — $ — $ — $ — CONSOLIDATING STATEMENT OF INCOME (Unaudited) For the three months ended March 31, 2017 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Revenues Premiums $ 4,228 $ 1,955 $ — $ — $ 6,183 Net investment income 412 194 4 — 610 Fee income 113 — — — 113 Net realized investment gains (losses) (1) (4 ) 9 — — 5 Other revenues 24 9 — (2 ) 31 Total revenues 4,773 2,167 4 (2 ) 6,942 Claims and expenses Claims and claim adjustment expenses 2,752 1,342 — — 4,094 Amortization of deferred acquisition costs 668 335 — — 1,003 General and administrative expenses 703 292 3 (2 ) 996 Interest expense 12 — 77 — 89 Total claims and expenses 4,135 1,969 80 (2 ) 6,182 Income (loss) before income taxes 638 198 (76 ) — 760 Income tax expense (benefit) 130 54 (41 ) — 143 Net income of subsidiaries — — 652 (652 ) — Net income $ 508 $ 144 $ 617 $ (652 ) $ 617 _________________________________________________________ (1) Total other-than-temporary impairments (OTTI) for the three months ended March 31, 2017 , and the amounts comprising total OTTI that were recognized in net realized investment gains (losses) and in other comprehensive income (OCI) were as follows: (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Total OTTI losses $ — $ (1 ) $ — $ — $ (1 ) OTTI losses recognized in net realized investment gains (losses) $ (1 ) $ (1 ) $ — $ — $ (2 ) OTTI gains recognized in OCI $ 1 $ — $ — $ — $ 1
Consolidating Statement of Comprehensive Income (Unaudited) [Table Text Block]	CONSOLIDATING STATEMENT OF COMPREHENSIVE INCOME (LOSS) (Unaudited) For the three months ended March 31, 2018 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Net income $ 551 $ 168 $ 669 $ (719 ) $ 669 Other comprehensive income (loss): Changes in net unrealized gains on investment securities: Having no credit losses recognized in the consolidated statement of income (838 ) (364 ) (1 ) — (1,203 ) Having credit losses recognized in the consolidated statement of income (1 ) (1 ) — — (2 ) Net changes in benefit plan assets and obligations — — 22 — 22 Net changes in unrealized foreign currency translation (25 ) 31 — — 6 Other comprehensive income (loss) before income taxes and other comprehensive loss of subsidiaries (864 ) (334 ) 21 — (1,177 ) Income tax expense (benefit) (175 ) (77 ) 8 — (244 ) Other comprehensive income (loss), net of taxes, before other comprehensive loss of subsidiaries (689 ) (257 ) 13 — (933 ) Other comprehensive loss of subsidiaries — — (946 ) 946 — Other comprehensive loss (689 ) (257 ) (933 ) 946 (933 ) Comprehensive loss $ (138 ) $ (89 ) $ (264 ) $ 227 $ (264 ) CONSOLIDATING STATEMENT OF COMPREHENSIVE INCOME (Unaudited) For the three months ended March 31, 2017 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Net income $ 508 $ 144 $ 617 $ (652 ) $ 617 Other comprehensive income: Changes in net unrealized gains on investment securities: Having no credit losses recognized in the consolidated statement of income 93 44 7 — 144 Having credit losses recognized in the consolidated statement of income 1 (1 ) — — — Net changes in benefit plan assets and obligations — — 17 — 17 Net changes in unrealized foreign currency translation 25 16 — — 41 Other comprehensive income before income taxes and other comprehensive income of subsidiaries 119 59 24 — 202 Income tax expense 37 16 9 — 62 Other comprehensive income, net of taxes, before other comprehensive income of subsidiaries 82 43 15 — 140 Other comprehensive income of subsidiaries — — 125 (125 ) — Other comprehensive income 82 43 140 (125 ) 140 Comprehensive income $ 590 $ 187 $ 757 $ (777 ) $ 757
Consolidating Balance Sheet (Unaudited) [Table Text Block]	CONSOLIDATING BALANCE SHEET (Unaudited) At March 31, 2018 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Assets Fixed maturities, available for sale, at fair value (amortized cost $62,093) $ 42,958 $ 19,225 $ 83 $ — $ 62,266 Equity securities, at fair value (cost $431) 147 103 180 — 430 Real estate investments 54 900 — — 954 Short-term securities 2,022 714 1,750 — 4,486 Other investments 2,745 842 1 — 3,588 Total investments 47,926 21,784 2,014 — 71,724 Cash 175 221 1 — 397 Investment income accrued 388 175 4 — 567 Premiums receivable 5,073 2,463 — — 7,536 Reinsurance recoverables 5,823 2,475 — — 8,298 Ceded unearned premiums 687 90 — — 777 Deferred acquisition costs 1,887 199 — — 2,086 Deferred taxes 115 271 (18 ) — 368 Contractholder receivables 3,907 928 — — 4,835 Goodwill 2,587 1,381 — (9 ) 3,959 Other intangible assets 201 140 — — 341 Investment in subsidiaries — — 27,090 (27,090 ) — Other assets 2,150 342 310 (14 ) 2,788 Total assets $ 70,919 $ 30,469 $ 29,401 $ (27,113 ) $ 103,676 Liabilities Claims and claim adjustment expense reserves $ 33,447 $ 16,363 $ — $ — $ 49,810 Unearned premium reserves 9,336 4,088 — — 13,424 Contractholder payables 3,907 928 — — 4,835 Payables for reinsurance premiums 295 203 — — 498 Debt 693 14 6,270 (14 ) 6,963 Other liabilities 3,922 1,091 154 — 5,167 Total liabilities 51,600 22,687 6,424 (14 ) 80,697 Shareholders’ equity Common stock (1,750.0 shares authorized; 270.3 shares issued and 270.2 shares outstanding) — 390 22,995 (390 ) 22,995 Additional paid-in capital 11,634 6,972 — (18,606 ) — Retained earnings 7,974 650 33,979 (8,622 ) 33,981 Accumulated other comprehensive loss (289 ) (230 ) (1,322 ) 519 (1,322 ) Treasury stock, at cost (503.7 shares) — — (32,675 ) — (32,675 ) Total shareholders’ equity 19,319 7,782 22,977 (27,099 ) 22,979 Total liabilities and shareholders’ equity $ 70,919 $ 30,469 $ 29,401 $ (27,113 ) $ 103,676 CONSOLIDATING BALANCE SHEET (Unaudited) At December 31, 2017 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Assets Fixed maturities, available for sale, at fair value (amortized cost $61,316) $ 43,240 $ 19,372 $ 82 $ — $ 62,694 Equity securities, available for sale, at fair value (cost $440) 161 111 181 — 453 Real estate investments 54 878 — — 932 Short-term securities 2,751 914 1,230 — 4,895 Other investments 2,673 854 1 — 3,528 Total investments 48,879 22,129 1,494 — 72,502 Cash 157 187 — — 344 Investment income accrued 418 183 5 — 606 Premiums receivable 4,852 2,292 — — 7,144 Reinsurance recoverables 5,842 2,467 — — 8,309 Ceded unearned premiums 493 58 — — 551 Deferred acquisition costs 1,835 190 — — 2,025 Deferred taxes (89 ) 173 (14 ) — 70 Contractholder receivables 3,854 921 — — 4,775 Goodwill 2,592 1,368 — (9 ) 3,951 Other intangible assets 202 140 — — 342 Investment in subsidiaries — — 27,946 (27,946 ) — Other assets 2,181 (3 ) 700 (14 ) 2,864 Total assets $ 71,216 $ 30,105 $ 30,131 $ (27,969 ) $ 103,483 Liabilities Claims and claim adjustment expense reserves $ 33,386 $ 16,264 $ — $ — $ 49,650 Unearned premium reserves 8,957 3,958 — — 12,915 Contractholder payables 3,854 921 — — 4,775 Payables for reinsurance premiums 165 109 — — 274 Debt 693 14 5,878 (14 ) 6,571 Other liabilities 4,161 882 524 — 5,567 Total liabilities 51,216 22,148 6,402 (14 ) 79,752 Shareholders’ equity Common stock (1,750.0 shares authorized; 271.5 shares issued and 271.4 shares outstanding) — 390 22,886 (390 ) 22,886 Additional paid-in capital 11,634 6,972 — (18,606 ) — Retained earnings 8,036 594 33,460 (8,628 ) 33,462 Accumulated other comprehensive income (loss) 330 1 (343 ) (331 ) (343 ) Treasury stock, at cost (500.9 shares) — — (32,274 ) — (32,274 ) Total shareholders’ equity 20,000 7,957 23,729 (27,955 ) 23,731 Total liabilities and shareholders’ equity $ 71,216 $ 30,105 $ 30,131 $ (27,969 ) $ 103,483
Consolidating Statement of Cash Flows (Unaudited) [Table Text Block]	CONSOLIDATING STATEMENT OF CASH FLOWS (Unaudited) For the three months ended March 31, 2018 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Cash flows from operating activities Net income $ 551 $ 168 $ 669 $ (719 ) $ 669 Net adjustments to reconcile net income to net cash provided by operating activities (126 ) (57 ) (22 ) 90 (115 ) Net cash provided by operating activities 425 111 647 (629 ) 554 Cash flows from investing activities Proceeds from maturities of fixed maturities 1,453 493 4 — 1,950 Proceeds from sales of investments: Fixed maturities 729 356 — — 1,085 Equity securities 8 18 — — 26 Real estate investments — — — — — Other investments 76 38 — — 114 Purchases of investments: Fixed maturities (2,836 ) (1,078 ) (6 ) — (3,920 ) Equity securities (1 ) (18 ) (1 ) — (20 ) Real estate investments — (33 ) — — (33 ) Other investments (115 ) (27 ) — — (142 ) Net sales (purchases) of short-term securities 729 201 (520 ) — 410 Securities transactions in course of settlement 147 56 (1 ) — 202 Other (52 ) (1 ) — — (53 ) Net cash provided by (used in) investing activities 138 5 (524 ) — (381 ) Cash flows from financing activities Treasury stock acquired — share repurchase authorization — — (350 ) — (350 ) Treasury stock acquired — net employee share-based compensation — — (51 ) — (51 ) Dividends paid to shareholders — — (197 ) — (197 ) Payment of debt — — (100 ) — (100 ) Issuance of debt — — 491 — 491 Issuance of common stock — employee share options — — 85 — 85 Dividends paid to parent company (544 ) (85 ) — 629 — Net cash used in financing activities (544 ) (85 ) (122 ) 629 (122 ) Effect of exchange rate changes on cash (1 ) 3 — — 2 Net increase in cash 18 34 1 — 53 Cash at beginning of year 157 187 — — 344 Cash at end of period $ 175 $ 221 $ 1 $ — $ 397 Supplemental disclosure of cash flow information Income taxes paid $ 13 $ 43 $ — $ — $ 56 Interest paid $ 16 $ — $ 23 $ — $ 39 CONSOLIDATING STATEMENT OF CASH FLOWS (Unaudited) For the three months ended March 31, 2017 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Cash flows from operating activities Net income $ 508 $ 144 $ 617 $ (652 ) $ 617 Net adjustments to reconcile net income to net cash provided by operating activities 160 9 205 (143 ) 231 Net cash provided by operating activities 668 153 822 (795 ) 848 Cash flows from investing activities Proceeds from maturities of fixed maturities 1,638 580 — — 2,218 Proceeds from sales of investments: Fixed maturities 88 100 — — 188 Equity securities 2 19 — — 21 Real estate investments — 11 — — 11 Other investments 96 26 — — 122 Purchases of investments: Fixed maturities (2,191 ) (864 ) (1 ) — (3,056 ) Equity securities (1 ) (20 ) (1 ) — (22 ) Real estate investments — (16 ) — — (16 ) Other investments (96 ) (28 ) — — (124 ) Net sales (purchases) of short-term securities 245 233 (429 ) — 49 Securities transactions in course of settlement 102 53 2 — 157 Other (70 ) 7 — — (63 ) Net cash provided by (used in) investing activities (187 ) 101 (429 ) — (515 ) Cash flows from financing activities Treasury stock acquired — share repurchase authorization — — (225 ) — (225 ) Treasury stock acquired — net employee share-based compensation — — (61 ) — (61 ) Dividends paid to shareholders — — (190 ) — (190 ) Issuance of common stock — employee share options — — 83 — 83 Dividends paid to parent company (532 ) (263 ) — 795 — Net cash used in financing activities (532 ) (263 ) (393 ) 795 (393 ) Effect of exchange rate changes on cash 1 1 — — 2 Net decrease in cash (50 ) (8 ) — — (58 ) Cash at beginning of year 141 164 2 — 307 Cash at end of period $ 91 $ 156 $ 2 $ — $ 249 Supplemental disclosure of cash flow information Income taxes paid $ 1 $ 1 $ — $ — $ 2 Interest paid $ 16 $ — $ 27 $ — $ 43

Basis of Presentation and Acc34

Basis of Presentation and Accounting Policies (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Jan. 01, 2018	Dec. 31, 2017
Accumulated other comprehensive income (loss), net of tax [Member]
New Accounting Pronouncements
Cumulative effect adjustment increasing (decreasing) equity		$ (22)	$ (22)
Reclassification of certain tax effects from adoption of updated accounting guidance	$ (24)
Retained earnings [Member]
New Accounting Pronouncements
Cumulative effect adjustment increasing (decreasing) equity			$ 22
Reclassification of certain tax effects from adoption of updated accounting guidance	24
Accounting Standards Update 2016-01 [Member] | Accumulated other comprehensive income (loss), net of tax [Member]
New Accounting Pronouncements
Cumulative effect adjustment increasing (decreasing) equity		(22)
Accounting Standards Update 2016-01 [Member] | Retained earnings [Member]
New Accounting Pronouncements
Cumulative effect adjustment increasing (decreasing) equity		$ 22
Accounting Standards Update 2018-02 [Member]
New Accounting Pronouncements
Reclassification of certain tax effects from adoption of updated accounting guidance	$ 24

Basis of Presentation and Acc35

Basis of Presentation and Accounting Policies (Details) - Revenue Recognition - Accounting Standards Update 2014-09 [Member] $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Revenues within scope of updated accounting guidance
Revenues within scope of updated accounting guidance	$ 40
Revenues within scope of updated accounting guidance, as a percentage of total revenues (less than)	1.00%

Basis of Presentation and Acc36

Basis of Presentation and Accounting Policies (Details) - Reportable Segments	3 Months Ended
	Mar. 31, 2018segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of reportable business segments	3

Segment Information (Details)

Segment Information (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Segment reporting information
Premiums		$ 6,537	$ 6,183
Net investment income		603	610
Fee income		103	113
Other revenues		54	31
Net realized investment gains (losses)	[1]	(11)	5
Total revenues		7,286	6,942
Core income		678	614
Net realized investment gains (losses), net of tax		(9)	3
Net income		669	617
Reportable Segments [Member]
Segment reporting information
Premiums		6,537	6,183
Net investment income		603	610
Fee income		103	113
Other revenues		54	30
Total segment revenues		7,297	6,936
Core income		754	676
Reportable Segments [Member] | Business Insurance [Member]
Segment reporting information
Premiums		3,568	3,429
Net investment income		446	453
Fee income		99	109
Other revenues		31	9
Total segment revenues		4,144	4,000
Core income		452	442
Reportable Segments [Member] | Business Insurance [Member] | Domestic [Member]
Segment reporting information
Premiums		3,304	3,189
Reportable Segments [Member] | Business Insurance [Member] | Domestic [Member] | Workers' compensation [Member]
Segment reporting information
Premiums		971	976
Reportable Segments [Member] | Business Insurance [Member] | Domestic [Member] | Automobile [Member]
Segment reporting information
Premiums		562	506
Reportable Segments [Member] | Business Insurance [Member] | Domestic [Member] | Commercial property [Member]
Segment reporting information
Premiums		438	435
Reportable Segments [Member] | Business Insurance [Member] | Domestic [Member] | General liability [Member]
Segment reporting information
Premiums		521	491
Reportable Segments [Member] | Business Insurance [Member] | Domestic [Member] | Commercial multi-peril [Member]
Segment reporting information
Premiums		805	774
Reportable Segments [Member] | Business Insurance [Member] | Domestic [Member] | Other [Member]
Segment reporting information
Premiums		7	7
Reportable Segments [Member] | Business Insurance [Member] | International [Member]
Segment reporting information
Premiums		264	240
Reportable Segments [Member] | Bond & Specialty Insurance [Member]
Segment reporting information
Premiums		582	555
Net investment income		58	61
Other revenues		6	5
Total segment revenues		646	621
Core income		173	145
Reportable Segments [Member] | Bond & Specialty Insurance [Member] | Domestic [Member]
Segment reporting information
Premiums		535	514
Reportable Segments [Member] | Bond & Specialty Insurance [Member] | Domestic [Member] | General liability [Member]
Segment reporting information
Premiums		242	235
Reportable Segments [Member] | Bond & Specialty Insurance [Member] | Domestic [Member] | Fidelity and surety [Member]
Segment reporting information
Premiums		246	234
Reportable Segments [Member] | Bond & Specialty Insurance [Member] | Domestic [Member] | Other [Member]
Segment reporting information
Premiums		47	45
Reportable Segments [Member] | Bond & Specialty Insurance [Member] | International [Member]
Segment reporting information
Premiums		47	41
Reportable Segments [Member] | Personal Insurance [Member]
Segment reporting information
Premiums		2,387	2,199
Net investment income		99	96
Fee income		4	4
Other revenues		17	16
Total segment revenues		2,507	2,315
Core income		129	89
Reportable Segments [Member] | Personal Insurance [Member] | Domestic [Member]
Segment reporting information
Premiums		2,220	2,049
Reportable Segments [Member] | Personal Insurance [Member] | Domestic [Member] | Automobile [Member]
Segment reporting information
Premiums		1,225	1,094
Reportable Segments [Member] | Personal Insurance [Member] | Domestic [Member] | Homeowners and Other [Member]
Segment reporting information
Premiums		995	955
Reportable Segments [Member] | Personal Insurance [Member] | International [Member]
Segment reporting information
Premiums		167	150
Other [Member]
Segment reporting information
Other revenues			1
Core income		(76)	(62)
After-tax interest expense		$ 70	$ 58
[1]	Total other-than-temporary impairment (OTTI) gains (losses) were $0 and $(1) million for the three months ended March 31, 2018 and 2017, respectively. Of total OTTI, credit losses of $0 and $(2) million for the three months ended March 31, 2018 and 2017, respectively, were recognized in net realized investment gains (losses). In addition, unrealized gains from other changes in total OTTI of $0 and $1 million for the three months ended March 31, 2018 and 2017, respectively, were recognized in other comprehensive income (loss) as part of changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income.

Segment Information (Details) -

Segment Information (Details) - Assets by Segment - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Assets by segment
Total assets	$ 103,676	$ 103,483
Reportable Segments [Member]
Assets by segment
Total assets	103,139	102,807
Reportable Segments [Member] | Business Insurance [Member]
Assets by segment
Total assets	78,747	78,082
Reportable Segments [Member] | Bond & Specialty Insurance [Member]
Assets by segment
Total assets	8,787	8,776
Reportable Segments [Member] | Personal Insurance [Member]
Assets by segment
Total assets	15,605	15,949
Other assets [Member]
Assets by segment
Total assets	$ 537	$ 676

Investments (Details)

Investments (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Investments [Abstract]
Proceeds from sales of fixed maturities classified as available for sale	$ 1,085	$ 188
Proceeds from sales of equity securities classified as available for sale		$ 21

Investments (Details) - Investm

Investments (Details) - Investment Information, Available for Sale Securities - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Investment disclosure details
Fixed maturities, amortized cost	$ 62,093		$ 61,316
Gross unrealized gains	859		1,556
Gross unrealized losses	686		178
Fixed maturities, at fair value	62,266		62,694
Equity securities, available for sale, cost			440
Gross gains			20
Gross losses			7
Equity securities, available for sale, at fair value			453
Continuous unrealized loss position, less than 12 months, fair value			9,153
Continuous unrealized loss position, less than 12 months, gross unrealized losses			68
Continuous unrealized loss position, 12 months or longer, fair value			5,870
Continuous unrealized loss position, 12 months or longer, gross unrealized losses			117
Continuous unrealized loss position, total, fair value			15,023
Continuous unrealized loss position, total, gross unrealized losses			185
Impairment charges	0	$ 2
Fixed maturities [Member]
Investment disclosure details
Gross realized gains	6	7
Gross realized losses	6	2
Continuous unrealized loss position, less than 12 months, fair value	23,876		9,132
Continuous unrealized loss position, less than 12 months, gross unrealized losses	442		68
Continuous unrealized loss position, 12 months or longer, fair value	5,589		5,780
Continuous unrealized loss position, 12 months or longer, gross unrealized losses	244		110
Continuous unrealized loss position, total, fair value	29,465		14,912
Continuous unrealized loss position, total, gross unrealized losses	686		178
Cumulative OTTI credit losses recognized for securities held	$ 75	$ 83
Cumulative credit component of other-than-temporary impairments (OTTI) on fixed maturities recognized in the consolidated statement of income for which a portion of the OTTI was recognized in other comprehensive income (loss) for fixed maturities held, as a percentage of the fixed maturity portfolio on a pre-tax basis (less than)	1.00%	1.00%
Cumulative credit component of other-than-temporary impairments (OTTI) on fixed maturities recognized in the consolidated statement of income for which a portion of the OTTI was recognized in other comprehensive income (loss) for fixed maturities held, as a percentage of shareholders' equity on an after-tax basis (less than)	1.00%	1.00%
U.S. Treasury securities and obligations of U.S. government and government agencies and authorities [Member]
Investment disclosure details
Fixed maturities, amortized cost	$ 2,051		2,080
Gross unrealized gains	2		4
Gross unrealized losses	19		8
Fixed maturities, at fair value	2,034		2,076
Continuous unrealized loss position, less than 12 months, fair value	1,332		1,150
Continuous unrealized loss position, less than 12 months, gross unrealized losses	15		5
Continuous unrealized loss position, 12 months or longer, fair value	549		470
Continuous unrealized loss position, 12 months or longer, gross unrealized losses	4		3
Continuous unrealized loss position, total, fair value	1,881		1,620
Continuous unrealized loss position, total, gross unrealized losses	19		8
Obligations of states, municipalities and political subdivisions [Member]
Investment disclosure details
Fixed maturities, amortized cost	29,134		29,996
Gross unrealized gains	536		968
Gross unrealized losses	230		49
Fixed maturities, at fair value	29,440		30,915
Continuous unrealized loss position, less than 12 months, fair value	5,823		505
Continuous unrealized loss position, less than 12 months, gross unrealized losses	94		2
Continuous unrealized loss position, 12 months or longer, fair value	2,863		2,959
Continuous unrealized loss position, 12 months or longer, gross unrealized losses	136		47
Continuous unrealized loss position, total, fair value	8,686		3,464
Continuous unrealized loss position, total, gross unrealized losses	230		49
Obligations of states, municipalities and political subdivisions, local general obligation [Member]
Investment disclosure details
Fixed maturities, amortized cost	13,593		13,488
Gross unrealized gains	215		444
Gross unrealized losses	127		26
Fixed maturities, at fair value	13,681		13,906
Obligations of states, municipalities and political subdivisions, revenue [Member]
Investment disclosure details
Fixed maturities, amortized cost	10,512		11,307
Gross unrealized gains	177		338
Gross unrealized losses	91		19
Fixed maturities, at fair value	10,598		11,626
Obligations of states, municipalities and political subdivisions, state general obligation [Member]
Investment disclosure details
Fixed maturities, amortized cost	1,391		1,443
Gross unrealized gains	21		44
Gross unrealized losses	12		3
Fixed maturities, at fair value	1,400		1,484
Obligations of states, municipalities and political subdivisions, pre-refunded [Member]
Investment disclosure details
Fixed maturities, amortized cost	3,638		3,758
Gross unrealized gains	123		142
Gross unrealized losses			1
Fixed maturities, at fair value	3,761		3,899
Debt securities issued by foreign governments [Member]
Investment disclosure details
Fixed maturities, amortized cost	1,326		1,505
Gross unrealized gains	9		14
Gross unrealized losses	8		10
Fixed maturities, at fair value	1,327		1,509
Continuous unrealized loss position, less than 12 months, fair value	431		394
Continuous unrealized loss position, less than 12 months, gross unrealized losses	7		6
Continuous unrealized loss position, 12 months or longer, fair value	32		111
Continuous unrealized loss position, 12 months or longer, gross unrealized losses	1		4
Continuous unrealized loss position, total, fair value	463		505
Continuous unrealized loss position, total, gross unrealized losses	8		10
Mortgage-backed securities, collateralized mortgage obligations and pass-through securities [Member]
Investment disclosure details
Fixed maturities, amortized cost	2,495		2,334
Gross unrealized gains	76		87
Gross unrealized losses	40		11
Fixed maturities, at fair value	2,531		2,410
Continuous unrealized loss position, less than 12 months, fair value	1,474		1,021
Continuous unrealized loss position, less than 12 months, gross unrealized losses	32		7
Continuous unrealized loss position, 12 months or longer, fair value	235		250
Continuous unrealized loss position, 12 months or longer, gross unrealized losses	8		4
Continuous unrealized loss position, total, fair value	1,709		1,271
Continuous unrealized loss position, total, gross unrealized losses	40		11
All other corporate bonds [Member]
Investment disclosure details
Fixed maturities, amortized cost	27,000		25,311
Gross unrealized gains	231		478
Gross unrealized losses	389		100
Fixed maturities, at fair value	26,842		25,689
Continuous unrealized loss position, less than 12 months, fair value	14,816		6,062
Continuous unrealized loss position, less than 12 months, gross unrealized losses	294		48
Continuous unrealized loss position, 12 months or longer, fair value	1,910		1,990
Continuous unrealized loss position, 12 months or longer, gross unrealized losses	95		52
Continuous unrealized loss position, total, fair value	16,726		8,052
Continuous unrealized loss position, total, gross unrealized losses	389		100
Redeemable preferred stock [Member]
Investment disclosure details
Fixed maturities, amortized cost	87		90
Gross unrealized gains	5		5
Fixed maturities, at fair value	$ 92		95
Equity securities [Member]
Investment disclosure details
Gross realized gains		$ 6
Gross realized losses		$ 1
Continuous unrealized loss position, less than 12 months, fair value			21
Continuous unrealized loss position, 12 months or longer, fair value			90
Continuous unrealized loss position, 12 months or longer, gross unrealized losses			7
Continuous unrealized loss position, total, fair value			111
Continuous unrealized loss position, total, gross unrealized losses			7
Public common stock [Member]
Investment disclosure details
Equity securities, available for sale, cost			332
Gross gains			8
Gross losses			1
Equity securities, available for sale, at fair value			339
Continuous unrealized loss position, less than 12 months, fair value			18
Continuous unrealized loss position, 12 months or longer, fair value			34
Continuous unrealized loss position, 12 months or longer, gross unrealized losses			1
Continuous unrealized loss position, total, fair value			52
Continuous unrealized loss position, total, gross unrealized losses			1
Non-redeemable preferred stock [Member]
Investment disclosure details
Equity securities, available for sale, cost			108
Gross gains			12
Gross losses			6
Equity securities, available for sale, at fair value			114
Continuous unrealized loss position, less than 12 months, fair value			3
Continuous unrealized loss position, 12 months or longer, fair value			56
Continuous unrealized loss position, 12 months or longer, gross unrealized losses			6
Continuous unrealized loss position, total, fair value			59
Continuous unrealized loss position, total, gross unrealized losses			$ 6

Investments (Details) - Inves41

Investments (Details) - Investment Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)
Investment disclosure details
Equity securities, cost	$ 431
Gross gains	15
Gross losses	16
Equity securities, at fair value	430
Equity securities [Member]
Investment disclosure details
Net recognized losses on equity securities still held	13
Public common stock [Member]
Investment disclosure details
Equity securities, cost	330
Gross gains	4
Gross losses	10
Equity securities, at fair value	324
Non-redeemable preferred stock [Member]
Investment disclosure details
Equity securities, cost	101
Gross gains	11
Gross losses	6
Equity securities, at fair value	$ 106

Investments (Details) - Derivat

Investments (Details) - Derivatives - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Futures [Member] | U.S. Treasury notes contracts [Member]
Derivatives
Notional value of open contracts	$ 250	$ 400

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Percent of fixed maturities for which a pricing service estimates fair value	98.00%	98.00%
Fair value of the fixed maturities for which the Company used an internal pricing matrix	$ 146	$ 127
Fair value of the fixed maturities for which the Company received a broker quote	$ 101	$ 77

Fair Value Measurements (Deta44

Fair Value Measurements (Details) - Fair Value Hierarchy - Recurring basis [Member] - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	$ 62,751	$ 63,204
Fixed maturities [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	62,266	62,694
U.S. Treasury securities and obligations of U.S. government and government agencies and authorities [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	2,034	2,076
Obligations of states, municipalities and political subdivisions [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	29,440	30,915
Debt securities issued by foreign governments [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	1,327	1,509
Mortgage-backed securities, collateralized mortgage obligations and pass-through securities [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	2,531	2,410
All other corporate bonds [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	26,842	25,689
Redeemable preferred stock [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	92	95
Equity securities [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	430	453
Public common stock [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	324	339
Non-redeemable preferred stock [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	106	114
Other Investments [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	55	57
Level 1 [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	2,421	2,493
Level 1 [Member] | Fixed maturities [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	2,038	2,090
Level 1 [Member] | U.S. Treasury securities and obligations of U.S. government and government agencies and authorities [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	2,034	2,076
Level 1 [Member] | All other corporate bonds [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	1	11
Level 1 [Member] | Redeemable preferred stock [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	3	3
Level 1 [Member] | Equity securities [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	366	384
Level 1 [Member] | Public common stock [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	324	339
Level 1 [Member] | Non-redeemable preferred stock [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	42	45
Level 1 [Member] | Other Investments [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	17	19
Level 2 [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	60,045	60,469
Level 2 [Member] | Fixed maturities [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	59,981	60,400
Level 2 [Member] | Obligations of states, municipalities and political subdivisions [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	29,428	30,910
Level 2 [Member] | Debt securities issued by foreign governments [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	1,327	1,509
Level 2 [Member] | Mortgage-backed securities, collateralized mortgage obligations and pass-through securities [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	2,491	2,371
Level 2 [Member] | All other corporate bonds [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	26,646	25,518
Level 2 [Member] | Redeemable preferred stock [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	89	92
Level 2 [Member] | Equity securities [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	64	69
Level 2 [Member] | Non-redeemable preferred stock [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	64	69
Level 3 [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	285	242
Level 3 [Member] | Fixed maturities [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	247	204
Level 3 [Member] | Obligations of states, municipalities and political subdivisions [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	12	5
Level 3 [Member] | Mortgage-backed securities, collateralized mortgage obligations and pass-through securities [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	40	39
Level 3 [Member] | All other corporate bonds [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	195	160
Level 3 [Member] | Other Investments [Member]
Level within the fair value hierarchy at which the Company's financial assets are measured
Total invested assets measured on a recurring basis	$ 38	$ 38

Fair Value Measurements (Deta45

Fair Value Measurements (Details) - Financial Instruments - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Financial Instruments
Short-term securities	$ 4,486	$ 4,895
Commercial paper	0	100
Carrying Value [Member]
Financial Instruments
Short-term securities	4,486	4,895
Debt	6,963	6,471
Commercial paper		100
Fair Value [Member]
Financial Instruments
Short-term securities	4,486	4,895
Debt	7,835	7,702
Commercial paper		100
Fair Value [Member] | Level 1 [Member]
Financial Instruments
Short-term securities	835	1,238
Fair Value [Member] | Level 2 [Member]
Financial Instruments
Short-term securities	3,612	3,622
Debt	7,835	7,702
Commercial paper		100
Fair Value [Member] | Level 3 [Member]
Financial Instruments
Short-term securities	$ 39	$ 35

Goodwill and Other Intangible46

Goodwill and Other Intangible Assets (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Goodwill by segment
Goodwill	$ 3,959	$ 3,951
Reportable Segments [Member] | Business Insurance [Member]
Goodwill by segment
Goodwill	2,597	2,585
Reportable Segments [Member] | Bond & Specialty Insurance [Member]
Goodwill by segment
Goodwill	550	550
Reportable Segments [Member] | Personal Insurance [Member]
Goodwill by segment
Goodwill	786	790
Other [Member]
Goodwill by segment
Goodwill	$ 26	$ 26

Goodwill and Other Intangible47

Goodwill and Other Intangible Assets (Details) - Other Intangible Assets - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Other intangible assets by major asset class
Intangible assets subject to amortization, gross carrying amount	$ 289		$ 286
Intangible assets subject to amortization, accumulated amortization	175		171
Intangible assets subject to amortization, net	114		115
Intangible assets not subject to amortization	227		227
Total other intangible assets, gross carrying amount	516		513
Total other intangible assets, net	341		342
Amortization expense of intangible assets	4	$ 3
Estimated intangible asset amortization expense, remainder of 2018	11
Estimated intangible asset amortization expense, 2019	14
Estimated intangible asset amortization expense, 2020	13
Estimated intangible asset amortization expense, 2021	12
Estimated intangible asset amortization expense, 2022	11
Customer-related [Member]
Other intangible assets by major asset class
Intangible assets subject to amortization, gross carrying amount	80		77
Intangible assets subject to amortization, accumulated amortization	5		4
Intangible assets subject to amortization, net	75		73
Contract-based [Member]
Other intangible assets by major asset class
Intangible assets subject to amortization, gross carrying amount	209		209
Intangible assets subject to amortization, accumulated amortization	170		167
Intangible assets subject to amortization, net	$ 39		$ 42

Insurance Claim Reserves (Detai

Insurance Claim Reserves (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Insurance Loss Reserves [Abstract]
Amount of increase in gross claims and claim adjustment expense reserves	$ 161
Amount of decrease in reinsurance recoverables on unpaid losses	55
Accretion of discount	$ 13	$ 13

Insurance Claim Reserves (Det49

Insurance Claim Reserves (Details) - Reserve Detail for Claims and Claim Adjustment Expenses - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Reconciliation of beginning and ending reserve balances for claims and claim adjustment expenses [Roll Forward]
Claims and claim adjustment expense reserves at beginning of year	$ 49,650
Claims and claim adjustment expense reserves at end of period	49,810
Property-casualty [Member]
Reconciliation of beginning and ending reserve balances for claims and claim adjustment expenses [Roll Forward]
Claims and claim adjustment expense reserves at beginning of year	49,633	$ 47,929
Reinsurance recoverables on unpaid losses	8,123	7,981
Net reserves at beginning of year	41,510	39,948
Estimated claims and claim adjustment expenses for claims arising in the current year	4,391	4,126
Estimated decrease in claims and claim adjustment expenses for claims arising in prior years	(116)	(50)
Total increases	4,275	4,076
Claims and claim adjustment expense payments for claims arising in current year	1,009	887
Claims and claim adjustment expense payments for claims arising in prior years	3,040	2,812
Total payments	4,049	3,699
Unrealized foreign exchange (gain) loss	(10)	34
Net reserves at end of period	41,726	40,359
Reinsurance recoverables on unpaid losses	8,068	7,942
Claims and claim adjustment expense reserves at end of period	49,794	$ 48,301
Accident and health [Member]
Reconciliation of beginning and ending reserve balances for claims and claim adjustment expenses [Roll Forward]
Claims and claim adjustment expense reserves at beginning of year	17
Claims and claim adjustment expense reserves at end of period	$ 16

Insurance Claim Reserves (Det50

Insurance Claim Reserves (Details) - Prior Year Reserve Development - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Liability for claims and claim adjustment expense
Net favorable prior year reserve development impacting the Company's results of operations	$ 150	$ 81
Business Insurance [Member]
Liability for claims and claim adjustment expense
Net favorable prior year reserve development impacting the Company's results of operations	66	61
Bond & Specialty Insurance [Member]
Liability for claims and claim adjustment expense
Net favorable prior year reserve development impacting the Company's results of operations	35	14
Personal Insurance [Member]
Liability for claims and claim adjustment expense
Net favorable prior year reserve development impacting the Company's results of operations	$ 49	$ 6

Other Comprehensive Income an51

Other Comprehensive Income and Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018	Dec. 31, 2017
Accumulated other comprehensive income [Roll Forward]
Balance, beginning of year	$ 23,731
Other comprehensive income (loss), net of taxes	(933)	$ 140
Balance, end of period	22,979	23,612
Pre-tax components of other comprehensive income (loss) and related tax expense (benefit)
Other comprehensive income (loss) before income taxes	(1,177)	202
Income tax expense (benefit)	(244)	62
Other comprehensive income (loss), net of taxes	(933)	140
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated other comprehensive income [Roll Forward]
Balance, beginning of year	(343)	(755)
Cumulative effect of adoption of updated accounting guidance for equity financial instruments, pre-tax			$ (34)
Cumulative effect of adoption of updated accounting guidance for equity financial instruments, tax			(12)
Cumulative effect of adoption of updated accounting guidance for equity financial instruments, net of income taxes			(22)	$ (22)
Reclassification of certain tax effects from adoption of updated accounting guidance	(24)
Effect of adoption of updated accounting guidance, net of tax, total			(46)
Other comprehensive income (loss) before reclassifications	(950)
Amounts reclassified from accumulated other comprehensive income	17
Other comprehensive income (loss), net of taxes	(933)	140
Balance, end of period	(1,322)	(615)
Pre-tax components of other comprehensive income (loss) and related tax expense (benefit)
Other comprehensive income (loss) before income taxes	(1,177)	202
Income tax expense (benefit)	(244)	62
Other comprehensive income (loss), net of taxes	(933)	140
Changes in Net Unrealized Gains on Investment Securities Having No Credit Losses Recognized in the Consolidated Statement of Income [Member]
Accumulated other comprehensive income [Roll Forward]
Balance, beginning of year	747
Cumulative effect of adoption of updated accounting guidance for equity financial instruments, pre-tax			(34)
Cumulative effect of adoption of updated accounting guidance for equity financial instruments, tax			(12)
Cumulative effect of adoption of updated accounting guidance for equity financial instruments, net of income taxes			(22)
Reclassification of certain tax effects from adoption of updated accounting guidance	145
Effect of adoption of updated accounting guidance, net of tax, total			123
Other comprehensive income (loss) before reclassifications	(950)
Other comprehensive income (loss), net of taxes	(950)	93
Balance, end of period	(80)
Pre-tax components of other comprehensive income (loss) and related tax expense (benefit)
Other comprehensive income (loss) before income taxes	(1,203)	144
Income tax expense (benefit)	(253)	51
Other comprehensive income (loss), net of taxes	(950)	93
Changes in Net Unrealized Gains on Investment Securities Having Credit Losses Recognized in the Consolidated Statement of Income [Member]
Accumulated other comprehensive income [Roll Forward]
Balance, beginning of year	207
Reclassification of certain tax effects from adoption of updated accounting guidance	7
Effect of adoption of updated accounting guidance, net of tax, total			7
Other comprehensive income (loss) before reclassifications	(1)
Other comprehensive income (loss), net of taxes	(1)
Balance, end of period	213
Pre-tax components of other comprehensive income (loss) and related tax expense (benefit)
Other comprehensive income (loss) before income taxes	(2)
Income tax expense (benefit)	(1)
Other comprehensive income (loss), net of taxes	(1)
Net Benefit Plan Assets and Obligations Recognized in Shareholders' Equity [Member]
Accumulated other comprehensive income [Roll Forward]
Balance, beginning of year	(686)
Reclassification of certain tax effects from adoption of updated accounting guidance	(141)
Effect of adoption of updated accounting guidance, net of tax, total			(141)
Amounts reclassified from accumulated other comprehensive income	17
Other comprehensive income (loss), net of taxes	17	12
Balance, end of period	(810)
Pre-tax components of other comprehensive income (loss) and related tax expense (benefit)
Other comprehensive income (loss) before income taxes	22	17
Income tax expense (benefit)	5	5
Other comprehensive income (loss), net of taxes	17	12
Net Unrealized Foreign Currency Translation [Member]
Accumulated other comprehensive income [Roll Forward]
Balance, beginning of year	(611)
Reclassification of certain tax effects from adoption of updated accounting guidance	(35)
Effect of adoption of updated accounting guidance, net of tax, total			$ (35)
Other comprehensive income (loss) before reclassifications	1
Other comprehensive income (loss), net of taxes	1	35
Balance, end of period	(645)
Pre-tax components of other comprehensive income (loss) and related tax expense (benefit)
Other comprehensive income (loss) before income taxes	6	41
Income tax expense (benefit)	5	6
Other comprehensive income (loss), net of taxes	$ 1	$ 35

Other Comprehensive Income an52

Other Comprehensive Income and Accumulated Other Comprehensive Income (Details) - Reclassifications - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Reclassification Adjustment out of Accumulated Other Comprehensive Income
Reclassification adjustment impacting net realized investment gains (losses) on the income statement	[1]	$ 11	$ (5)
Reclassification adjustment impacting claims and claim adjustment expenses on the income statement		4,296	4,094
Reclassification adjustment impacting general and administrative expense on the income statement		1,062	996
Total reclassifications		(778)	(760)
Income tax (expense) benefit		(109)	(143)
Amounts reclassified from accumulated other comprehensive income, net of taxes		(669)	(617)
Accumulated Other Comprehensive Income (Loss) [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income
Total reclassifications		22	7
Income tax (expense) benefit		5	2
Amounts reclassified from accumulated other comprehensive income, net of taxes		17	5
Changes in Net Unrealized Gains on Investment Securities Having No Credit Losses Recognized in the Consolidated Statement of Income [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income
Reclassification adjustment impacting net realized investment gains (losses) on the income statement			(10)
Income tax (expense) benefit			(3)
Amounts reclassified from accumulated other comprehensive income, net of taxes			(7)
Net Benefit Plan Assets and Obligations Recognized in Shareholders' Equity [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income
Reclassification adjustment impacting claims and claim adjustment expenses on the income statement		9	7
Reclassification adjustment impacting general and administrative expense on the income statement		13	10
Total reclassifications		22	17
Income tax (expense) benefit		5	5
Amounts reclassified from accumulated other comprehensive income, net of taxes		$ 17	$ 12
[1]	Total other-than-temporary impairment (OTTI) gains (losses) were $0 and $(1) million for the three months ended March 31, 2018 and 2017, respectively. Of total OTTI, credit losses of $0 and $(2) million for the three months ended March 31, 2018 and 2017, respectively, were recognized in net realized investment gains (losses). In addition, unrealized gains from other changes in total OTTI of $0 and $1 million for the three months ended March 31, 2018 and 2017, respectively, were recognized in other comprehensive income (loss) as part of changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income.

Debt (Details)

Debt (Details) - USD ($)	Mar. 07, 2018	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument
Net proceeds of issuance, after the deduction of the underwriting discount and expenses		$ 491,000,000
Basis points added to current Treasury rate used in calculation of alternative redemption price	0.15%
Commercial paper outstanding		$ 0	$ 100,000,000
4.05% Senior notes due March 7, 2048 [Member]
Debt Instrument
Debt, principal amount	$ 500,000,000
Interest rate (percent)	4.05%
Net proceeds of issuance, after the deduction of the underwriting discount and expenses	$ 491,000,000
Percentage of principal amount at which redemption price may be set	100.00%	100.00%

Common Share Repurchases (Detai

Common Share Repurchases (Details) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018USD ($)$ / sharesshares
Treasury Stock Transactions, Excluding Value of Shares Reissued [Abstract]
Number of shares repurchased (in shares) | shares	2.5
Cost of shares repurchased	$ 350
Average cost per share repurchased (in dollars per share) | $ / shares	$ 141.84
Number of shares acquired to cover tax withholding costs and exercise costs (in shares) | shares	0.3
Cost of shares acquired to cover tax withholding costs and exercise costs	$ 51
Remaining capacity under share repurchase authorization	$ 4,210

Earnings per Share (Details)

Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share Reconciliation [Abstract]
Net income	$ 669	$ 617
Participating share-based awards — allocated income	(5)	(4)
Net income available to common shareholders -- basic	664	613
Net income available to common shareholders -- diluted	$ 664	$ 613
Weighted average shares outstanding, basic (in shares)	271	279.7
Weighted average effects of dilutive securities - stock options and performance shares (in shares)	2.9	2.7
Weighted average shares outstanding, diluted (in shares)	273.9	282.4
Net income per common share, basic (in dollars per share)	$ 2.45	$ 2.19
Net income per common share, diluted (in dollars per share)	$ 2.42	$ 2.17

Share-Based Incentive Compens56

Share-Based Incentive Compensation (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock options vested at end of period, number (in shares)	6,207,090
Stock options vested at end of period, weighted average exercise price (in dollars per share)	$ 98.23
Stock options vested at end of period, weighted average contractual life remaining (in years)	6 years 7 months 6 days
Stock options vested at end of period, aggregate intrinsic value	$ 253
Stock options exercisable at end of period, number (in shares)	3,696,007
Stock options exercisable at end of period, weighted average exercise price (in dollars per share)	$ 84.13
Stock options exercisable at end of period, weighted average contractual life remaining (in years)	5 years 2 months 12 days
Stock options exercisable at end of period, aggregate intrinsic value	$ 202
Total compensation cost recognized in earnings for all share-based incentive compensation awards	44	$ 42
Tax benefit recognized in earnings related to compensation costs	8	$ 14
Total unrecognized compensation cost related to all nonvested share-based incentive compensation awards	$ 233
Weighted-average period of recognition for unrecognized compensation cost (in years)	2 years 2 months 12 days

Pension Plans, Retirement Ben57

Pension Plans, Retirement Benefits and Savings Plans (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Pension Plans [Member]
Defined benefit plan disclosure
Service cost	$ 33	$ 30
Interest cost on benefit obligation	31	31
Expected return on plan assets	(66)	(60)
Net periodic benefit cost, amortization of unrecognized net actuarial loss	23	18
Total non-service cost (benefit)	(12)	(11)
Net periodic benefit cost	21	19
Pension Plans [Member] | Claims and claim adjustment expenses [Member]
Defined benefit plan disclosure
Service cost	13	12
Total non-service cost (benefit)	(5)	(4)
Pension Plans [Member] | General and administrative expenses [Member]
Defined benefit plan disclosure
Service cost	20	18
Total non-service cost (benefit)	(7)	(7)
Postretirement Benefit Plans [Member]
Defined benefit plan disclosure
Interest cost on benefit obligation	2	2
Net periodic benefit cost, amortization of unrecognized prior service benefit	(1)	(1)
Total non-service cost (benefit)	1	1
Net periodic benefit cost	1	1
Postretirement Benefit Plans [Member] | General and administrative expenses [Member]
Defined benefit plan disclosure
Total non-service cost (benefit)	$ 1	$ 1

Contingencies, Commitments an58

Contingencies, Commitments and Guarantees (Details) - Commitments - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Unfunded commitments to private equity limited partnerships and real estate partnerships	$ 1,610	$ 1,560

Contingencies, Commitments an59

Contingencies, Commitments and Guarantees (Details) - Guarantees $ in Millions	Mar. 31, 2018USD ($)
Indemnifications related to the sale of businesses [Member]
Guarantor obligations
Maximum amount of contingent obligation	$ 358
Amount recognized on balance sheet for contingent obligation	1
Guarantees of certain investments and third-party loans [Member]
Guarantor obligations
Maximum amount of contingent obligation	45
Amount indemnified by a third party	23
Guarantees of certain insurance policy obligations [Member]
Guarantor obligations
Amount indemnified by a third party	$ 480

Consolidating Financial State60

Consolidating Financial Statements (Unaudited) (Details) $ in Millions	Mar. 31, 2018USD ($)
Consolidating Financial Statements of The Travelers Companies, Inc. and Subsidiaries (Unaudited) disclosure
Amount of certain debt obligations of Travelers Property Casualty Corp. (TPC) and Travelers Insurance Group Holdings, Inc. (TIGHI) that are unconditionally guaranteed by The Travelers Companies, Inc.	$ 700

Consolidating Financial State61

Consolidating Financial Statements (Details) - Consolidating Statement of Income (Unaudited) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Consolidating Statement of Income
Premiums		$ 6,537	$ 6,183
Net investment income		603	610
Fee income		103	113
Net realized investment gains (losses)	[1]	(11)	5
Other revenues		54	31
Total revenues		7,286	6,942
Claims and claim adjustment expenses		4,296	4,094
Amortization of deferred acquisition costs		1,061	1,003
General and administrative expenses		1,062	996
Interest expense		89	89
Total claims and expenses		6,508	6,182
Income before income taxes		778	760
Income tax expense (benefit)		109	143
Net income		669	617
Total other-than-temporary impairment losses		0	(1)
Other-than-temporary impairment losses recognized in net realized investment gains (losses)		0	(2)
Other-than-temporary impairment gains recognized in other comprehensive income		0	1
Reportable Legal Entities [Member] | TPC [Member]
Consolidating Statement of Income
Premiums		4,468	4,228
Net investment income		412	412
Fee income		103	113
Net realized investment gains (losses)		2	(4)
Other revenues		27	24
Total revenues		5,012	4,773
Claims and claim adjustment expenses		2,910	2,752
Amortization of deferred acquisition costs		705	668
General and administrative expenses		729	703
Interest expense		11	12
Total claims and expenses		4,355	4,135
Income before income taxes		657	638
Income tax expense (benefit)		106	130
Net income		551	508
Other-than-temporary impairment losses recognized in net realized investment gains (losses)			(1)
Other-than-temporary impairment gains recognized in other comprehensive income			1
Reportable Legal Entities [Member] | Other Subsidiaries [Member]
Consolidating Statement of Income
Premiums		2,069	1,955
Net investment income		185	194
Net realized investment gains (losses)		(12)	9
Other revenues		28	9
Total revenues		2,270	2,167
Claims and claim adjustment expenses		1,386	1,342
Amortization of deferred acquisition costs		356	335
General and administrative expenses		328	292
Total claims and expenses		2,070	1,969
Income before income taxes		200	198
Income tax expense (benefit)		32	54
Net income		168	144
Total other-than-temporary impairment losses			(1)
Other-than-temporary impairment losses recognized in net realized investment gains (losses)			(1)
Reportable Legal Entities [Member] | TRV [Member]
Consolidating Statement of Income
Net investment income		6	4
Net realized investment gains (losses)		(1)
Total revenues		5	4
General and administrative expenses		6	3
Interest expense		78	77
Total claims and expenses		84	80
Income before income taxes		(79)	(76)
Income tax expense (benefit)		(29)	(41)
Net income of subsidiaries		719	652
Net income		669	617
Eliminations [Member]
Consolidating Statement of Income
Other revenues		(1)	(2)
Total revenues		(1)	(2)
General and administrative expenses		(1)	(2)
Total claims and expenses		(1)	(2)
Net income of subsidiaries		(719)	(652)
Net income		$ (719)	$ (652)
[1]	Total other-than-temporary impairment (OTTI) gains (losses) were $0 and $(1) million for the three months ended March 31, 2018 and 2017, respectively. Of total OTTI, credit losses of $0 and $(2) million for the three months ended March 31, 2018 and 2017, respectively, were recognized in net realized investment gains (losses). In addition, unrealized gains from other changes in total OTTI of $0 and $1 million for the three months ended March 31, 2018 and 2017, respectively, were recognized in other comprehensive income (loss) as part of changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income.

Consolidating Financial State62

Consolidating Financial Statements (Details) - Consolidating Statement of Comprehensive Income (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Consolidating Statement of Comprehensive Income
Net income	$ 669	$ 617
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	(1,203)	144
Changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	(2)
Net changes in benefit plan assets and obligations	22	17
Net changes in unrealized foreign currency translation	6	41
Other comprehensive income (loss) before income taxes	(1,177)	202
Income tax expense (benefit)	(244)	62
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	(933)	140
Other comprehensive income (loss), net of taxes	(933)	140
Comprehensive income (loss)	(264)	757
Reportable Legal Entities [Member] | TPC [Member]
Consolidating Statement of Comprehensive Income
Net income	551	508
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	(838)	93
Changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	(1)	1
Net changes in unrealized foreign currency translation	(25)	25
Other comprehensive income (loss) before income taxes	(864)	119
Income tax expense (benefit)	(175)	37
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	(689)	82
Other comprehensive income (loss), net of taxes	(689)	82
Comprehensive income (loss)	(138)	590
Reportable Legal Entities [Member] | Other Subsidiaries [Member]
Consolidating Statement of Comprehensive Income
Net income	168	144
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	(364)	44
Changes in net unrealized gains on investment securities having credit losses recognized in the consolidated statement of income	(1)	(1)
Net changes in unrealized foreign currency translation	31	16
Other comprehensive income (loss) before income taxes	(334)	59
Income tax expense (benefit)	(77)	16
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	(257)	43
Other comprehensive income (loss), net of taxes	(257)	43
Comprehensive income (loss)	(89)	187
Reportable Legal Entities [Member] | TRV [Member]
Consolidating Statement of Comprehensive Income
Net income	669	617
Changes in net unrealized gains on investment securities having no credit losses recognized in the consolidated statement of income	(1)	7
Net changes in benefit plan assets and obligations	22	17
Other comprehensive income (loss) before income taxes	21	24
Income tax expense (benefit)	8	9
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	13	15
Other comprehensive income (loss) of subsidiaries	(946)	125
Other comprehensive income (loss), net of taxes	(933)	140
Comprehensive income (loss)	(264)	757
Eliminations [Member]
Consolidating Statement of Comprehensive Income
Net income	(719)	(652)
Other comprehensive income (loss) of subsidiaries	946	(125)
Other comprehensive income (loss), net of taxes	946	(125)
Comprehensive income (loss)	$ 227	$ (777)

Consolidating Financial State63

Consolidating Financial Statements (Details) - Consolidating Balance Sheet (Unaudited) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Consolidating Balance Sheet
Fixed maturities, at fair value	$ 62,266	$ 62,694
Equity securities, at fair value	430
Equity securities, available for sale, at fair value		453
Real estate investments	954	932
Short-term securities	4,486	4,895
Other investments	3,588	3,528
Total investments	71,724	72,502
Cash	397	344	$ 249	$ 307
Investment income accrued	567	606
Premiums receivable	7,536	7,144
Reinsurance recoverables	8,298	8,309
Ceded unearned premiums	777	551
Deferred acquisition costs	2,086	2,025
Deferred taxes	368	70
Contractholder receivables	4,835	4,775
Goodwill	3,959	3,951
Other intangible assets	341	342
Other assets	2,788	2,864
Total assets	103,676	103,483
Claims and claim adjustment expense reserves	49,810	49,650
Unearned premium reserves	13,424	12,915
Contractholder payables	4,835	4,775
Payables for reinsurance premiums	498	274
Debt	6,963	6,571
Other liabilities	5,167	5,567
Total liabilities	80,697	79,752
Common stock	22,995	22,886
Retained earnings	33,981	33,462
Accumulated other comprehensive income (loss)	(1,322)	(343)
Treasury stock, at cost	(32,675)	(32,274)
Total shareholders’ equity	22,979	23,731	23,612
Total liabilities and shareholders’ equity	103,676	103,483
Fixed maturities, available for sale, amortized cost	62,093	61,316
Equity securities, cost	$ 431
Equity securities, available for sale, cost		$ 440
Common stock, shares authorized (in shares)	1,750,000,000	1,750,000,000
Common stock, shares issued (in shares)	270,300,000	271,500,000
Common stock, shares outstanding (in shares)	270,200,000	271,400,000
Treasury stock, at cost (in shares)	503,700,000	500,900,000
Reportable Legal Entities [Member] | TPC [Member]
Consolidating Balance Sheet
Fixed maturities, at fair value	$ 42,958	$ 43,240
Equity securities, at fair value	147
Equity securities, available for sale, at fair value		161
Real estate investments	54	54
Short-term securities	2,022	2,751
Other investments	2,745	2,673
Total investments	47,926	48,879
Cash	175	157	91	141
Investment income accrued	388	418
Premiums receivable	5,073	4,852
Reinsurance recoverables	5,823	5,842
Ceded unearned premiums	687	493
Deferred acquisition costs	1,887	1,835
Deferred taxes	115	(89)
Contractholder receivables	3,907	3,854
Goodwill	2,587	2,592
Other intangible assets	201	202
Other assets	2,150	2,181
Total assets	70,919	71,216
Claims and claim adjustment expense reserves	33,447	33,386
Unearned premium reserves	9,336	8,957
Contractholder payables	3,907	3,854
Payables for reinsurance premiums	295	165
Debt	693	693
Other liabilities	3,922	4,161
Total liabilities	51,600	51,216
Additional paid-in capital	11,634	11,634
Retained earnings	7,974	8,036
Accumulated other comprehensive income (loss)	(289)	330
Total shareholders’ equity	19,319	20,000
Total liabilities and shareholders’ equity	70,919	71,216
Reportable Legal Entities [Member] | Other Subsidiaries [Member]
Consolidating Balance Sheet
Fixed maturities, at fair value	19,225	19,372
Equity securities, at fair value	103
Equity securities, available for sale, at fair value		111
Real estate investments	900	878
Short-term securities	714	914
Other investments	842	854
Total investments	21,784	22,129
Cash	221	187	156	164
Investment income accrued	175	183
Premiums receivable	2,463	2,292
Reinsurance recoverables	2,475	2,467
Ceded unearned premiums	90	58
Deferred acquisition costs	199	190
Deferred taxes	271	173
Contractholder receivables	928	921
Goodwill	1,381	1,368
Other intangible assets	140	140
Other assets	342	(3)
Total assets	30,469	30,105
Claims and claim adjustment expense reserves	16,363	16,264
Unearned premium reserves	4,088	3,958
Contractholder payables	928	921
Payables for reinsurance premiums	203	109
Debt	14	14
Other liabilities	1,091	882
Total liabilities	22,687	22,148
Common stock	390	390
Additional paid-in capital	6,972	6,972
Retained earnings	650	594
Accumulated other comprehensive income (loss)	(230)	1
Total shareholders’ equity	7,782	7,957
Total liabilities and shareholders’ equity	30,469	30,105
Reportable Legal Entities [Member] | TRV [Member]
Consolidating Balance Sheet
Fixed maturities, at fair value	83	82
Equity securities, at fair value	180
Equity securities, available for sale, at fair value		181
Short-term securities	1,750	1,230
Other investments	1	1
Total investments	2,014	1,494
Cash	1		$ 2	$ 2
Investment income accrued	4	5
Deferred taxes	(18)	(14)
Investment in subsidiaries	27,090	27,946
Other assets	310	700
Total assets	29,401	30,131
Debt	6,270	5,878
Other liabilities	154	524
Total liabilities	6,424	6,402
Common stock	22,995	22,886
Retained earnings	33,979	33,460
Accumulated other comprehensive income (loss)	(1,322)	(343)
Treasury stock, at cost	(32,675)	(32,274)
Total shareholders’ equity	22,977	23,729
Total liabilities and shareholders’ equity	29,401	30,131
Eliminations [Member]
Consolidating Balance Sheet
Goodwill	(9)	(9)
Investment in subsidiaries	(27,090)	(27,946)
Other assets	(14)	(14)
Total assets	(27,113)	(27,969)
Debt	(14)	(14)
Total liabilities	(14)	(14)
Common stock	(390)	(390)
Additional paid-in capital	(18,606)	(18,606)
Retained earnings	(8,622)	(8,628)
Accumulated other comprehensive income (loss)	519	(331)
Total shareholders’ equity	(27,099)	(27,955)
Total liabilities and shareholders’ equity	$ (27,113)	$ (27,969)

Consolidating Financial State64

Consolidating Financial Statements (Details) - Consolidating Statement of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Consolidating Statement of Cash Flows
Net income	$ 669	$ 617
Net adjustments to reconcile net income to net cash provided by operating activities	(115)	231
Net cash provided by operating activities	554	848
Proceeds from maturities of fixed maturities	1,950	2,218
Proceeds from sales of investments:
Fixed maturities	1,085	188
Equity securities	26
Equity securities		21
Real estate investments		11
Other investments	114	122
Purchases of investments:
Fixed maturities	(3,920)	(3,056)
Equity securities	(20)
Equity securities		(22)
Real estate investments	(33)	(16)
Other investments	(142)	(124)
Net sales (purchases) of short-term securities	410	49
Securities transactions in course of settlement	202	157
Other investing activities	(53)	(63)
Net cash used in investing activities	(381)	(515)
Treasury stock acquired — share repurchase authorization	(350)	(225)
Treasury stock acquired — net employee share-based compensation	(51)	(61)
Dividends paid to shareholders	(197)	(190)
Payment of debt	(100)
Issuance of debt	491
Issuance of common stock — employee share options	85	83
Net cash used in financing activities	(122)	(393)
Effect of exchange rate changes on cash	2	2
Net increase (decrease) in cash	53	(58)
Cash at beginning of year	344	307
Cash at end of period	397	249
Income taxes paid	56	2
Interest paid	39	43
Reportable Legal Entities [Member] | TPC [Member]
Consolidating Statement of Cash Flows
Net income	551	508
Net adjustments to reconcile net income to net cash provided by operating activities	(126)	160
Net cash provided by operating activities	425	668
Proceeds from maturities of fixed maturities	1,453	1,638
Proceeds from sales of investments:
Fixed maturities	729	88
Equity securities	8
Equity securities		2
Other investments	76	96
Purchases of investments:
Fixed maturities	(2,836)	(2,191)
Equity securities	(1)
Equity securities		(1)
Other investments	(115)	(96)
Net sales (purchases) of short-term securities	729	245
Securities transactions in course of settlement	147	102
Other investing activities	(52)	(70)
Net cash used in investing activities	138	(187)
Dividends paid to parent company	(544)	(532)
Net cash used in financing activities	(544)	(532)
Effect of exchange rate changes on cash	(1)	1
Net increase (decrease) in cash	18	(50)
Cash at beginning of year	157	141
Cash at end of period	175	91
Income taxes paid	13	1
Interest paid	16	16
Reportable Legal Entities [Member] | Other Subsidiaries [Member]
Consolidating Statement of Cash Flows
Net income	168	144
Net adjustments to reconcile net income to net cash provided by operating activities	(57)	9
Net cash provided by operating activities	111	153
Proceeds from maturities of fixed maturities	493	580
Proceeds from sales of investments:
Fixed maturities	356	100
Equity securities	18
Equity securities		19
Real estate investments		11
Other investments	38	26
Purchases of investments:
Fixed maturities	(1,078)	(864)
Equity securities	(18)
Equity securities		(20)
Real estate investments	(33)	(16)
Other investments	(27)	(28)
Net sales (purchases) of short-term securities	201	233
Securities transactions in course of settlement	56	53
Other investing activities	(1)	7
Net cash used in investing activities	5	101
Dividends paid to parent company	(85)	(263)
Net cash used in financing activities	(85)	(263)
Effect of exchange rate changes on cash	3	1
Net increase (decrease) in cash	34	(8)
Cash at beginning of year	187	164
Cash at end of period	221	156
Income taxes paid	43	1
Reportable Legal Entities [Member] | TRV [Member]
Consolidating Statement of Cash Flows
Net income	669	617
Net adjustments to reconcile net income to net cash provided by operating activities	(22)	205
Net cash provided by operating activities	647	822
Proceeds from maturities of fixed maturities	4
Purchases of investments:
Fixed maturities	(6)	(1)
Equity securities	(1)
Equity securities		(1)
Net sales (purchases) of short-term securities	(520)	(429)
Securities transactions in course of settlement	(1)	2
Net cash used in investing activities	(524)	(429)
Treasury stock acquired — share repurchase authorization	(350)	(225)
Treasury stock acquired — net employee share-based compensation	(51)	(61)
Dividends paid to shareholders	(197)	(190)
Payment of debt	(100)
Issuance of debt	491
Issuance of common stock — employee share options	85	83
Net cash used in financing activities	(122)	(393)
Net increase (decrease) in cash	1
Cash at beginning of year		2
Cash at end of period	1	2
Interest paid	23	27
Eliminations [Member]
Consolidating Statement of Cash Flows
Net income	(719)	(652)
Net adjustments to reconcile net income to net cash provided by operating activities	90	(143)
Net cash provided by operating activities	(629)	(795)
Purchases of investments:
Dividends paid to parent company	629	795
Net cash used in financing activities	$ 629	$ 795