The Travelers Companies, Inc. (TRV) 10-Q 18 Apr 19 2019 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2019	Apr. 15, 2019
Document and Entity Information
Registrant name	Travelers Companies, Inc.
Central index key	0000086312
Document type	10-Q
Document period end date	Mar. 31, 2019
Amendment flag	false
Current fiscal year end date	--12-31
Filer category	Large Accelerated Filer
Entity emerging growth company	false
Entity small business	false
Common stock shares outstanding		261,908,210
Document fiscal year focus	2019
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, 2019	Mar. 31, 2018
Revenues
Premiums		$ 6,855	$ 6,537
Net investment income		582	603
Fee income		109	103
Net realized investment gains (losses)	[1]	53	(11)
Other revenues		72	54
Total revenues		7,671	7,286
Claims and expenses
Claims and claim adjustment expenses		4,442	4,296
Amortization of deferred acquisition costs		1,117	1,061
General and administrative expenses		1,057	1,062
Interest expense		88	89
Total claims and expenses		6,704	6,508
Income before income taxes		967	778
Income tax expense		171	109
Net income		$ 796	$ 669
Net income per share
Basic (in dollars per share)		$ 3.01	$ 2.45
Diluted (in dollars per share)		$ 2.99	$ 2.42
Weighted average number of common shares outstanding
Basic (in shares)		262.9	271
Diluted (in shares)		264.8	273.9
Cash dividends declared per common share (in dollars per share)		$ 0.77	$ 0.72
[1]	Total other-than-temporary impairment (OTTI) gains (losses) were $(1) million and $0 for the three months ended March 31, 2019 and 2018, respectively. Of total OTTI, credit losses of $(1) million and $0 for the three months ended March 31, 2019 and 2018, respectively, were recognized in net realized investment gains (losses). In addition, unrealized gains (losses) from other changes in total OTTI of $0 for each of the three months ended March 31, 2019 and 2018, respectively, were recognized in other comprehensive income (loss) as part of changes in net unrealized gains (losses) on investment securities having credit losses recognized in the consolidated statement of income.

Consolidated Statement of Inc_2

Consolidated Statement of Income Parentheticals (Unaudited) - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Income Statement [Abstract]
Total other-than-temporary impairment gains (losses)	$ (1,000,000)	$ 0
Other-than-temporary impairment, credit losses recognized in net realized investment gains (losses)	(1,000,000)	0
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 (losses) on investment securities having credit losses recognized in the consolidated statement of income		$ 0
Unrealized (losses) from other changes in total other-than-temporary impairments recognized in other comprehensive income (loss) as part of changes in net unrealized gains (losses) on investment securities having credit losses recognized in the consolidated statement of income	$ 0

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 796	$ 669
Other comprehensive income (loss):
Changes in net unrealized gains (losses) on investment securities having no credit losses recognized in the consolidated statement of income	1,416	(1,203)
Changes in net unrealized gains (losses) on investment securities having credit losses recognized in the consolidated statement of income	5	(2)
Net changes in benefit plan assets and obligations	12	22
Net changes in unrealized foreign currency translation	50	6
Other comprehensive income (loss) before income taxes	1,483	(1,177)
Income tax expense (benefit)	306	(244)
Other comprehensive income (loss), net of taxes	1,177	(933)
Comprehensive income (loss)	$ 1,973	$ (264)

Consolidated Balance Sheet (Una

Consolidated Balance Sheet (Unaudited at March 31, 2019) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Assets
Fixed maturities, available for sale, at fair value (amortized cost $64,216 and $63,601)	$ 65,500	$ 63,464
Equity securities, at fair value (cost $375 and $382)	400	368
Real estate investments	969	904
Short-term securities	4,094	3,985
Other investments	3,554	3,557
Total investments	74,517	72,278
Cash	357	373	$ 397	$ 344
Investment income accrued	591	624
Premiums receivable	7,947	7,506
Reinsurance recoverables	8,281	8,370
Ceded unearned premiums	935	578
Deferred acquisition costs	2,190	2,120
Deferred taxes	115	445
Contractholder receivables	4,811	4,785
Goodwill	3,949	3,937
Other intangible assets	341	345
Other assets	3,212	2,872
Total assets	107,246	104,233
Liabilities
Claims and claim adjustment expense reserves	50,718	50,668
Unearned premium reserves	14,122	13,555
Contractholder payables	4,811	4,785
Payables for reinsurance premiums	635	289
Debt	7,057	6,564
Other liabilities	5,563	5,478
Total liabilities	82,906	81,339
Shareholders’ equity
Common stock (1,750.0 shares authorized; 262.0 and 263.7 shares issued, 261.9 and 263.6 shares outstanding)	23,243	23,144
Retained earnings	35,795	35,204
Accumulated other comprehensive loss	(682)	(1,859)
Treasury stock, at cost (514.2 and 510.9 shares)	(34,016)	(33,595)
Total shareholders’ equity	24,340	22,894	$ 22,979
Total liabilities and shareholders’ equity	$ 107,246	$ 104,233

Consolidated Balance Sheet Pare

Consolidated Balance Sheet Parentheticals (Unaudited at March 31, 2019) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Fixed maturities, available for sale, amortized cost	$ 64,216	$ 63,601
Equity securities, cost	$ 375	$ 382
Common stock, shares authorized (in shares)	1,750,000,000	1,750,000,000
Common stock, shares issued (in shares)	262,000,000	263,700,000
Common stock, shares outstanding (in shares)	261,900,000	263,600,000
Treasury stock, at cost (in shares)	514,200,000	510,900,000

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 loss, net of tax [Member]	Treasury stock, at cost [Member]	Common shares outstanding [Member]
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		$ 22,886	33,462	(343)	$ (32,274)
Shareholders' Equity [Roll Forward]
Employee share-based compensation		65
Compensation amortization under share-based plans and other changes		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)
Net shares acquired related to employee share-based compensation plans					(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
Common shares outstanding
Treasury stock acquired - share repurchase authorization (in shares)						(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
Balance, beginning of year at Dec. 31, 2018	22,894	23,144	35,204	(1,859)	(33,595)
Shareholders' Equity [Roll Forward]
Employee share-based compensation		54
Compensation amortization under share-based plans and other changes		45
Net income	796		796
Dividends			(204)
Other			(1)
Other comprehensive income (loss)	1,177			1,177
Treasury stock acquired — share repurchase authorization	(375)				(375)
Net shares acquired related to employee share-based compensation plans	(46)				(46)
Balance, end of period at Mar. 31, 2019	$ 24,340	$ 23,243	$ 35,795	$ (682)	$ (34,016)
Balance, beginning of year (in shares) at Dec. 31, 2018	263.6					263.6
Common shares outstanding
Treasury stock acquired - share repurchase authorization (in shares)	(2.9)					(2.9)
Net shares issued under employee share-based compensation plans (in shares)						1.2
Balance, end of period (in shares) at Mar. 31, 2019	261.9					261.9

Consolidated Statement of Cash

Consolidated Statement of Cash Flows (Unaudited) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Cash flows from operating activities
Net income		$ 796	$ 669
Adjustments to reconcile net income to net cash provided by operating activities:
Net realized investment (gains) losses	[1]	(53)	11
Depreciation and amortization		211	212
Deferred federal income tax expense (benefit)		32	(56)
Amortization of deferred acquisition costs		1,117	1,061
Equity in income from other investments		(34)	(95)
Premiums receivable		(434)	(397)
Reinsurance recoverables		98	5
Deferred acquisition costs		(1,185)	(1,124)
Claims and claim adjustment expense reserves		(2)	180
Unearned premium reserves		551	518
Other operating activities		(458)	(430)
Net cash provided by operating activities		639	554
Cash flows from investing activities
Proceeds from maturities of fixed maturities		1,556	1,950
Proceeds from sales of investments:
Fixed maturities		769	1,085
Equity securities		39	26
Other investments		105	114
Purchases of investments:
Fixed maturities		(2,914)	(3,920)
Equity securities		(22)	(20)
Real estate investments		(77)	(33)
Other investments		(146)	(142)
Net sales (purchases) of short-term securities		(109)	410
Securities transactions in course of settlement		295	202
Other investing activities		(82)	(53)
Net cash used in investing activities		(586)	(381)
Cash flows from financing activities
Treasury stock acquired — share repurchase authorization		(375)	(350)
Treasury stock acquired — net employee share-based compensation		(46)	(51)
Dividends paid to shareholders		(205)	(197)
Payment of debt			(100)
Issuance of debt		492	491
Issuance of common stock — employee share options		63	85
Net cash used in financing activities		(71)	(122)
Effect of exchange rate changes on cash		2	2
Net increase (decrease) in cash		(16)	53
Cash at beginning of year		373	344
Cash at end of period		357	397
Supplemental disclosure of cash flow information
Income taxes paid		5	56
Interest paid		$ 50	$ 39
[1]	Total other-than-temporary impairment (OTTI) gains (losses) were $(1) million and $0 for the three months ended March 31, 2019 and 2018, respectively. Of total OTTI, credit losses of $(1) million and $0 for the three months ended March 31, 2019 and 2018, respectively, were recognized in net realized investment gains (losses). In addition, unrealized gains (losses) from other changes in total OTTI of $0 for each of the three months ended March 31, 2019 and 2018, respectively, were recognized in other comprehensive income (loss) as part of changes in net unrealized gains (losses) 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, 2019
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, 2018 (the Company’s 2018 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. Adoption of Accounting Standards Leases Effective for the quarter ended March 31, 2019, the Company adopted the updated guidance for leases and elected to utilize a cumulative-effect adjustment to the opening balance of retained earnings for the year of adoption. Accordingly, the Company’s reporting for the comparative periods prior to adoption continue to be presented in the financial statements in accordance with previous lease accounting guidance. The Company also elected to apply all practical expedients applicable to the Company in the updated guidance for transition for leases in effect at adoption, including using hindsight to determine the lease term of existing leases, the option to not reassess whether an existing contract is a lease or contains a lease and whether the lease is an operating or finance lease. The adoption of the updated guidance resulted in the Company recognizing a right-of-use asset of $320 million as part of other assets and a lease liability of $384 million as part of other liabilities in the consolidated balance sheet, as well as de-recognizing the liability for deferred rent that was required under the previous guidance, for its corporate real estate agreements at March 31, 2019. The cumulative effect adjustment to the opening balance of retained earnings was zero . The adoption of the updated guidance did not have a material effect on the Company’s results of operations or liquidity. Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract Effective for the quarter ended March 31, 2019, the Company adopted the updated guidance regarding Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract , and applied the guidance prospectively. The updated guidance requires an entity to determine the stage of a project that the implementation activity relates to and the nature of the associated costs in order to determine whether those costs should be expensed as incurred or capitalized. The updated guidance also requires the entity to amortize the capitalized implementation costs as an expense over the term of the hosting arrangement. The adoption of the updated guidance did not have a material effect on the Company’s results of operations, financial position or liquidity. For additional information regarding accounting standards that the Company adopted during the periods presented, see note 1 of notes to the consolidated financial statements in the Company’s 2018 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 2018 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 2018 Annual Report.

Segment Information

Segment Information	3 Months Ended
	Mar. 31, 2019
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 2019 Premiums $ 3,742 $ 606 $ 2,507 $ 6,855 Net investment income 427 56 99 582 Fee income 104 — 5 109 Other revenues 43 6 22 71 Total segment revenues (1) $ 4,316 $ 668 $ 2,633 $ 7,617 Segment income (1) $ 414 $ 138 $ 278 $ 830 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 _________________________________________________________ (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) 2019 2018 Revenue reconciliation Earned premiums Business Insurance: Domestic: Workers’ compensation $ 972 $ 971 Commercial automobile 628 562 Commercial property 460 438 General liability 567 521 Commercial multi-peril 840 805 Other 8 7 Total Domestic 3,475 3,304 International 267 264 Total Business Insurance 3,742 3,568 Bond & Specialty Insurance: Domestic: Fidelity and surety 246 246 General liability 257 242 Other 52 47 Total Domestic 555 535 International 51 47 Total Bond & Specialty Insurance 606 582 Personal Insurance: Domestic: Automobile 1,297 1,225 Homeowners and Other 1,039 995 Total Domestic 2,336 2,220 International 171 167 Total Personal Insurance 2,507 2,387 Total earned premiums 6,855 6,537 Net investment income 582 603 Fee income 109 103 Other revenues 71 54 Total segment revenues 7,617 7,297 Other revenues 1 — Net realized investment gains (losses) 53 (11 ) Total revenues $ 7,671 $ 7,286 Income reconciliation, net of tax Total segment income $ 830 $ 754 Interest Expense and Other (1) (75 ) (76 ) Core income 755 678 Net realized investment gains (losses) 41 (9 ) Net income $ 796 $ 669 _________________________________________________________ (1) The primary component of Interest Expense and Other was after-tax interest expense of $70 million for both the three months ended March 31, 2019 and 2018 . (in millions) March 31, December 31, Asset reconciliation Business Insurance $ 82,022 $ 78,965 Bond & Specialty Insurance 8,363 8,693 Personal Insurance 16,288 15,943 Total assets by reportable segment 106,673 103,601 Other assets (1) 573 632 Total consolidated assets $ 107,246 $ 104,233 _________________________________________________________ (1) The primary components of other assets at both March 31, 2019 and December 31, 2018 were accrued over-funded benefit plan assets related to the Company’s qualified domestic pension plan and other intangible assets.

Investments

Investments	3 Months Ended
	Mar. 31, 2019
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, 2019, in millions) Cost Gains Losses Value U.S. Treasury securities and obligations of U.S. government and government agencies and authorities $ 2,029 $ 7 $ 6 $ 2,030 Obligations of states, municipalities and political subdivisions: Local general obligation 14,879 468 14 15,333 Revenue 9,757 336 8 10,085 State general obligation 1,300 37 2 1,335 Pre-refunded 2,515 79 — 2,594 Total obligations of states, municipalities and political subdivisions 28,451 920 24 29,347 Debt securities issued by foreign governments 1,184 12 2 1,194 Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 2,601 64 16 2,649 All other corporate bonds 29,873 482 156 30,199 Redeemable preferred stock 78 3 — 81 Total $ 64,216 $ 1,488 $ 204 $ 65,500 Amortized Gross Unrealized Fair (at December 31, 2018, in millions) Cost Gains Losses Value U.S. Treasury securities and obligations of U.S. government and government agencies and authorities $ 2,076 $ 4 $ 16 $ 2,064 Obligations of states, municipalities and political subdivisions: Local general obligation 14,473 219 120 14,572 Revenue 9,755 172 74 9,853 State general obligation 1,329 18 13 1,334 Pre-refunded 2,772 80 — 2,852 Total obligations of states, municipalities and political subdivisions 28,329 489 207 28,611 Debt securities issued by foreign governments 1,255 7 5 1,257 Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 2,557 54 38 2,573 All other corporate bonds 29,307 156 583 28,880 Redeemable preferred stock 77 2 — 79 Total $ 63,601 $ 712 $ 849 $ 63,464 Pre-refunded bonds of $2.59 billion and $2.85 billion at March 31, 2019 and December 31, 2018 , 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 $769 million and $1.09 billion during the three months ended March 31, 2019 and 2018 , respectively. Gross gains of $21 million and $6 million and gross losses of $4 million and $6 million were realized on those sales during the three months ended March 31, 2019 and 2018 , respectively. Equity Securities The cost and fair value of investments in equity securities were as follows: Fair (at March 31, 2019, in millions) Cost Gross Gains Gross Losses Value Public common stock $ 339 $ 24 $ 6 $ 357 Non-redeemable preferred stock 36 7 — 43 Total $ 375 $ 31 $ 6 $ 400 Fair (at December 31, 2018, in millions) Cost Gross Gains Gross Losses Value Public common stock $ 338 $ 2 $ 24 $ 316 Non-redeemable preferred stock 44 8 — 52 Total $ 382 $ 10 $ 24 $ 368 For the three months ended March 31, 2019 , the Company recognized $39 million of net gains on equity securities still held as of March 31, 2019 . 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 . Unrealized Investment Losses The following tables summarize, for all investments in an unrealized loss position at March 31, 2019 and December 31, 2018 , 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 2018 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 2018 Annual Report to determine whether such investments are other-than-temporarily impaired. Less than 12 months 12 months or longer Total (at March 31, 2019, 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 $ 51 $ — $ 1,056 $ 6 $ 1,107 $ 6 Obligations of states, municipalities and political subdivisions 103 — 2,464 24 2,567 24 Debt securities issued by foreign governments 15 — 255 2 270 2 Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 32 — 1,333 16 1,365 16 All other corporate bonds 551 7 9,622 149 10,173 156 Total fixed maturities $ 752 $ 7 $ 14,730 $ 197 $ 15,482 $ 204 Less than 12 months 12 months or longer Total (at December 31, 2018, 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 $ 484 $ 5 $ 1,011 $ 11 $ 1,495 $ 16 Obligations of states, municipalities and political subdivisions 5,241 82 3,298 125 8,539 207 Debt securities issued by foreign governments 96 — 328 5 424 5 Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 593 9 1,070 29 1,663 38 All other corporate bonds 12,622 303 6,872 280 19,494 583 Total fixed maturities $ 19,036 $ 399 $ 12,579 $ 450 $ 31,615 $ 849 At March 31, 2019 , the amount of gross unrealized losses for all fixed maturity investments reported at fair value for which fair value was less than 80% of amortized cost was not significant. Impairment Charges Impairment charges included in net realized investment gains (losses) in the consolidated statement of income were $1 million and $0 for the three months ended March 31, 2019 and 2018 , respectively. The cumulative amount of credit losses on fixed maturities held at March 31, 2019 and 2018 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 $56 million and $75 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, 2019 and 2018 compared to what was disclosed in note 3 of notes to the consolidated financial statements in the Company’s 2018 Annual Report.

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2019
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 99% of its fixed maturities at both March 31, 2019 and December 31, 2018 . 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 also estimates the fair value of these bonds using another internal pricing matrix that includes 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 this internal pricing matrix was $96 million and $82 million at March 31, 2019 and December 31, 2018 , 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 $19 million and $104 million at March 31, 2019 and December 31, 2018 , 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 2018 Annual Report. Other Liabilities The Company has a put/call option that was entered into in connection with a business acquisition that allows the Company to acquire the remaining shares of the acquired company at a future date. The fair value of the put/call at both March 31, 2019 and December 31, 2018 was $10 million and was determined using an internal model and is based on the acquired company's financial performance, adjusted for a risk margin and discounted to present value. The Company includes the fair value estimate of the put/call in Level 3. 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. (at March 31, 2019, 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 $ 2,030 $ 2,030 $ — $ — Obligations of states, municipalities and political subdivisions 29,347 — 29,335 12 Debt securities issued by foreign governments 1,194 — 1,194 — Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 2,649 — 2,649 — All other corporate bonds 30,199 4 30,092 103 Redeemable preferred stock 81 3 78 — Total fixed maturities 65,500 2,037 63,348 115 Equity securities Public common stock 357 356 1 — Non-redeemable preferred stock 43 14 29 — Total equity securities 400 370 30 — Other investments 58 16 — 42 Total $ 65,958 $ 2,423 $ 63,378 $ 157 Other liabilities $ 10 $ — $ — $ 10 (at December 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 $ 2,064 $ 2,064 $ — $ — Obligations of states, municipalities and political subdivisions 28,611 — 28,599 12 Debt securities issued by foreign governments 1,257 — 1,257 — Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 2,573 — 2,554 19 All other corporate bonds 28,880 — 28,725 155 Redeemable preferred stock 79 3 76 — Total fixed maturities 63,464 2,067 61,211 186 Equity securities Public common stock 316 316 — — Non-redeemable preferred stock 52 30 22 — Total equity securities 368 346 22 — Other investments 52 16 — 36 Total $ 63,884 $ 2,429 $ 61,233 $ 222 Other liabilities $ 10 $ — $ — $ 10 There was no significant activity in Level 3 of the hierarchy during the three months ended March 31, 2019 or the year ended December 31, 2018 . 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, 2019, in millions) Carrying Value Fair Value Level 1 Level 2 Level 3 Financial assets Short-term securities $ 4,094 $ 4,094 $ 483 $ 3,567 $ 44 Financial liabilities Debt $ 6,957 $ 7,984 $ — $ 7,984 $ — Commercial paper $ 100 $ 100 $ — $ 100 $ — (at December 31, 2018, in millions) Carrying Value Fair Value Level 1 Level 2 Level 3 Financial assets Short-term securities $ 3,985 $ 3,985 $ 632 $ 3,316 $ 37 Financial liabilities Debt $ 6,464 $ 7,128 $ — $ 7,128 $ — 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, 2019 or year ended December 31, 2018 .

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	3 Months Ended
	Mar. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
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 $ 2,594 $ 2,585 Bond & Specialty Insurance 550 550 Personal Insurance 779 776 Other 26 26 Total $ 3,949 $ 3,937 Other Intangible Assets The following tables present a summary of the Company’s other intangible assets by major asset class. (at March 31, 2019, in millions) Gross Carrying Amount Accumulated Amortization Net Subject to amortization Customer-related $ 100 $ 15 $ 85 Contract-based (1) 204 174 30 Total subject to amortization 304 189 115 Not subject to amortization 226 — 226 Total $ 530 $ 189 $ 341 (at December 31, 2018, in millions) Gross Carrying Amount Accumulated Amortization Net Subject to amortization Customer-related $ 98 $ 12 $ 86 Contract-based (1) 208 175 33 Total subject to amortization 306 187 119 Not subject to amortization 226 — 226 Total $ 532 $ 187 $ 345 _________________________________________________________ (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 for both the three months ended March 31, 2019 and 2018 . Intangible asset amortization expense is estimated to be $12 million for the remainder of 2019 , $15 million in 2020 , $14 million in 2021 , $13 million in 2022 and $12 million in 2023 . Amortization expense for intangible assets arising from insurance contracts acquired in a business combination is estimated to be $4 million for the remainder of 2019, $5 million in 2020, $4 million in 2021, $3 million in 2022 and $3 million in 2023.

Insurance Claim Reserves

Insurance Claim Reserves	3 Months Ended
	Mar. 31, 2019
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 $ 50,704 $ 50,653 Accident and health 14 15 Total $ 50,718 $ 50,668 The following table presents a reconciliation of beginning and ending property casualty reserve balances for claims and claim adjustment expenses: Three Months Ended (in millions) 2019 2018 Claims and claim adjustment expense reserves at beginning of year $ 50,653 $ 49,633 Less reinsurance recoverables on unpaid losses 8,182 8,123 Net reserves at beginning of year 42,471 41,510 Estimated claims and claim adjustment expenses for claims arising in the current year 4,435 4,391 Estimated decrease in claims and claim adjustment expenses for claims arising in prior years (16 ) (116 ) Total increases 4,419 4,275 Claims and claim adjustment expense payments for claims arising in: Current year 970 1,009 Prior years 3,320 3,040 Total payments 4,290 4,049 Unrealized foreign exchange (gain) loss 41 (10 ) Net reserves at end of period 42,641 41,726 Plus reinsurance recoverables on unpaid losses 8,063 8,068 Claims and claim adjustment expense reserves at end of period $ 50,704 $ 49,794 Gross claims and claim adjustment expense reserves at March 31, 2019 increased by $51 million from December 31, 2018 , 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 three months of 2019, partially offset by the impacts of (iii) payments related to catastrophe losses incurred in 2018 and (iv) net favorable prior year reserve development. Reinsurance recoverables on unpaid losses at March 31, 2019 decreased by $119 million from December 31, 2018 , primarily reflecting the impact of cash collections in the first three months of 2019. Prior Year Reserve Development The following disclosures regarding reserve development are on a “net of reinsurance” basis. For the three months ended March 31, 2019 and 2018 , estimated claims and claim adjustment expenses incurred included $16 million and $116 million , respectively, of net favorable development for claims arising in prior years, including $51 million and $150 million , respectively, of net favorable prior year reserve development and $12 million and $13 million , respectively, of accretion of discount that impacted the Company's results of operations. Business Insurance. Net unfavorable prior year reserve development in the first quarter of 2019 totaled $21 million , primarily driven by higher than expected loss experience in the segment's domestic operations in (i) the general liability product line for multiple accident years, primarily for years prior to 2009, due to the enactment by New York State of the Child Victims Act (“CVA”) on February 14, 2019 and (ii) the commercial multi-peril product line for recent accident years, partially offset by (iii) better than expected loss experience in the segment's domestic operations in the workers’ compensation product line for multiple accident years. The CVA extends the statute of limitations for claimants asserting childhood sexual molestation, including a “reviver” component that allows claimants of any age to file a civil claim during a one-year window beginning six months after the CVA took effect. 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. Bond & Specialty Insurance. Net favorable prior year reserve development in the first quarter of 2019 of $3 million was not significant. 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. Personal Insurance. Net favorable prior year reserve development in the first quarter of 2019 totaled $69 million , primarily driven by better than expected loss experience in the segment's domestic operations in the automobile product line for recent accident years. 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.

Other Comprehensive Income and

Other Comprehensive Income and Accumulated Other Comprehensive Income	3 Months Ended
	Mar. 31, 2019
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, 2019 . Changes in Net Unrealized Gains (Losses) 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, 2018 $ (306 ) $ 193 $ (873 ) $ (873 ) $ (1,859 ) Other comprehensive income (OCI) before reclassifications, net of tax 1,129 4 — 47 1,180 Amounts reclassified from AOCI, net of tax (13 ) — 10 — (3 ) Net OCI, current period 1,116 4 10 47 1,177 Balance, March 31, 2019 $ 810 $ 197 $ (863 ) $ (826 ) $ (682 ) 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) 2019 2018 Changes in net unrealized gains (losses) on investment securities: Having no credit losses recognized in the consolidated statement of income $ 1,416 $ (1,203 ) Income tax expense (benefit) 300 (253 ) Net of taxes 1,116 (950 ) Having credit losses recognized in the consolidated statement of income 5 (2 ) Income tax expense (benefit) 1 (1 ) Net of taxes 4 (1 ) Net changes in benefit plan assets and obligations 12 22 Income tax expense 2 5 Net of taxes 10 17 Net changes in unrealized foreign currency translation 50 6 Income tax expense 3 5 Net of taxes 47 1 Total other comprehensive income (loss) 1,483 (1,177 ) Total income tax expense (benefit) 306 (244 ) Total other comprehensive income (loss), net of taxes $ 1,177 $ (933 ) 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) 2019 2018 Reclassification adjustments related to unrealized gains (losses) on investment securities: Having no credit losses recognized in the consolidated statement of income (1) $ (16 ) $ — Income tax expense (2) (3 ) — Net of taxes (13 ) — 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) 5 9 General and administrative expenses (3) 8 13 Total 13 22 Income tax benefit (2) 3 5 Net of taxes 10 17 Reclassification adjustment related to foreign currency translation (1) — — Income tax benefit (2) — — Net of taxes — — Total reclassifications (3 ) 22 Total income tax (expense) benefit — 5 Total reclassifications, net of taxes $ (3 ) $ 17 _________________________________________________________ (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, 2019
Debt Disclosure [Abstract]
Debt	DEBT Debt Issuance . On March 4, 2019, the Company issued $500 million aggregate principal amount of 4.10% senior notes that will mature on March 4, 2049. The net proceeds of the issuance, after the deduction of the underwriting discount and expenses payable by the Company, totaled approximately $492 million . Interest on the senior notes is payable semi-annually in arrears on March 4 and September 4. Prior to September 4, 2048, 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 4, 2048 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 20 basis points. On or after September 4, 2048, 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 $100 million of commercial paper outstanding at both March 31, 2019 and December 31, 2018 .

Common Share Repurchases

Common Share Repurchases	3 Months Ended
	Mar. 31, 2019
Treasury Stock Transactions, Excluding Value of Shares Reissued [Abstract]
Common Share Repurchases	COMMON SHARE REPURCHASES During the three months ended March 31, 2019 , the Company repurchased 2.9 million shares under its share repurchase authorization, for a total cost of $375 million . The average cost per share repurchased was $129.42 . In addition, the Company acquired 0.4 million shares for a total cost of $46 million during the three months ended March 31, 2019 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, 2019 , the Company had $2.91 billion of capacity remaining under its share repurchase authorization.

Earnings per Share

Earnings per Share	3 Months Ended
	Mar. 31, 2019
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) 2019 2018 Basic and Diluted Net income, as reported $ 796 $ 669 Participating share-based awards — allocated income (5 ) (5 ) Net income available to common shareholders — basic and diluted $ 791 $ 664 Common Shares Basic Weighted average shares outstanding 262.9 271.0 Diluted Weighted average shares outstanding 262.9 271.0 Weighted average effects of dilutive securities — stock options and performance shares 1.9 2.9 Total 264.8 273.9 Net Income per Common Share Basic $ 3.01 $ 2.45 Diluted $ 2.99 $ 2.42

Share-Based Incentive Compensat

Share-Based Incentive Compensation	3 Months Ended
	Mar. 31, 2019
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, 2019 : Stock Options Number Weighted Average Exercise Price Weighted Average Contractual Life Remaining Aggregate Intrinsic Value ($ in millions) Vested at end of period (1) 7,029,165 $ 103.80 5.8 years $ 237 Exercisable at end of period 5,124,196 $ 94.88 4.7 years $ 217 _________________________________________________________ (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 $45 million and $44 million for the three months ended March 31, 2019 and 2018 , respectively. The related tax benefits recognized in the consolidated statement of income were $8 million for both the three months ended March 31, 2019 and 2018 . The total unrecognized compensation cost related to all nonvested share-based incentive compensation awards at March 31, 2019 was $235 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, 2019
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, 2019 and 2018 . Pension Plans Postretirement Benefit Plans (for the three months ended March 31, in millions) 2019 2018 2019 2018 Net Periodic Benefit Cost: Service cost $ 30 $ 33 $ — $ — Non-service cost: Interest cost on benefit obligation 35 31 2 2 Expected return on plan assets (69 ) (66 ) — — Amortization of unrecognized: Prior service benefit — — (1 ) (1 ) Net actuarial loss 14 23 — — Total non-service cost (benefit) (20 ) (12 ) 1 1 Net periodic benefit cost $ 10 $ 21 $ 1 $ 1 The following table indicates the line items in which the respective service costs and non-service cost (benefit) are presented in the consolidated statement of income for the three months ended March 31, 2019 and 2018 . Pension Plans Postretirement Benefit Plans (for the three months ended March 31, in millions) 2019 2018 2019 2018 Service Cost: Claims and claim adjustment expenses $ 12 $ 13 $ — $ — General and administrative expenses 18 20 — — Total service cost 30 33 — — Non-Service Cost (Benefit): Claims and claim adjustment expenses (8 ) (5 ) — — General and administrative expenses (12 ) (7 ) 1 1 Total non-service cost (benefit) (20 ) (12 ) 1 1 Net periodic benefit cost $ 10 $ 21 $ 1 $ 1

Leases

Leases	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Leases	LEASES The Company enters into lease agreements for real estate that is primarily used for office space in the ordinary course of business. These leases are accounted for as operating leases, whereby lease expense is recognized on a straight-line basis over the term of the lease. See note 1 - Adoption of Accounting Standards - Leases for additional information regarding the accounting for leases. Most leases include an option to extend or renew the lease term. The exercise of the renewal option is at the Company's discretion. The operating lease liability includes lease payments related to options to extend or renew the lease term if the Company is reasonably certain of exercising those options. The Company, in determining the present value of lease payments, utilizes either the rate implicit in the lease if that rate is readily determinable or the Company’s incremental secured borrowing rate commensurate with the term of the underlying lease. Lease expense is included in general and administrative expenses in the consolidated statement of income. Additional information regarding the Company’s real estate operating leases is as follows: (in millions) Three Months Ended Lease cost Operating leases $ 22 Short-term leases (1) 4 Lease expense 26 Less: sublease income (2) — Net lease cost $ 26 Other information on operating leases Cash payments included in the measurement of lease liabilities reported in operating cash flows $ 24 Right-of-use assets obtained in exchange for new lease liabilities $ 8 Weighted average discount rate 3.07 % Weighted average remaining lease term in years 5.2 years _________________________________________________________ (1) Leases with an initial term of twelve months or less are not recorded on the balance sheet. (2) Sublease income consists of rent from third parties of office space and is recognized as part of other revenues in the consolidated statement of income. The following table presents the contractual maturities of the Company's lease liabilities: (in millions) Real Estate Lease Liability Remainder of 2019 $ 73 2020 95 2021 82 2022 61 2023 41 Thereafter 62 Total undiscounted lease payments 414 Less: present value adjustment 30 Operating lease liability $ 384

Contingencies, Commitments and

Contingencies, Commitments and Guarantees	3 Months Ended
	Mar. 31, 2019
Contingencies, Commitments and Guarantees [Abstract]
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 future loss development for claims and litigation relating to asbestos and environmental claims. Any such development could be affected by future court decisions and interpretations, as well as future changes, if any, 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 $1.56 billion and $1.60 billion at March 31, 2019 and December 31, 2018 , 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, 2019 . 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 $0 at March 31, 2019 . 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, 2019 , 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 2018 Annual Report.

Consolidating Financial Stateme

Consolidating Financial Statements (Unaudited)	3 Months Ended
	Mar. 31, 2019
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, 2019 . 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, 2019 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Revenues Premiums $ 4,689 $ 2,166 $ — $ — $ 6,855 Net investment income 416 155 11 — 582 Fee income 109 — — — 109 Net realized investment gains (1) 22 15 16 — 53 Other revenues 38 34 — — 72 Total revenues 5,274 2,370 27 — 7,671 Claims and expenses Claims and claim adjustment expenses 3,024 1,418 — — 4,442 Amortization of deferred acquisition costs 745 372 — — 1,117 General and administrative expenses 722 330 5 — 1,057 Interest expense 12 — 76 — 88 Total claims and expenses 4,503 2,120 81 — 6,704 Income (loss) before income taxes 771 250 (54 ) — 967 Income tax expense (benefit) 146 42 (17 ) — 171 Net income of subsidiaries — — 833 (833 ) — Net income $ 625 $ 208 $ 796 $ (833 ) $ 796 ____________________________________________________ (1) Total other-than-temporary impairments (OTTI) for the three months ended March 31, 2019 , and the amounts comprising total OTTI that were recognized in net realized investment gains 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 $ (1 ) $ — $ — $ — $ (1 ) OTTI losses recognized in OCI $ — $ — $ — $ — $ — 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 COMPREHENSIVE INCOME (Unaudited) For the three months ended March 31, 2019 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Net income $ 625 $ 208 $ 796 $ (833 ) $ 796 Other comprehensive income: Changes in net unrealized gains (losses) on investment securities: Having no credit losses recognized in the consolidated statement of income 979 435 2 — 1,416 Having credit losses recognized in the consolidated statement of income 4 1 — — 5 Net changes in benefit plan assets and obligations — — 12 — 12 Net changes in unrealized foreign currency translation 19 31 — — 50 Other comprehensive income before income taxes and other comprehensive income of subsidiaries 1,002 467 14 — 1,483 Income tax expense 208 93 5 — 306 Other comprehensive income, net of taxes, before other comprehensive income of subsidiaries 794 374 9 — 1,177 Other comprehensive income of subsidiaries — — 1,168 (1,168 ) — Other comprehensive income 794 374 1,177 (1,168 ) 1,177 Comprehensive income $ 1,419 $ 582 $ 1,973 $ (2,001 ) $ 1,973 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 (losses) 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 BALANCE SHEET (Unaudited) At March 31, 2019 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Assets Fixed maturities, available for sale, at fair value (amortized cost $64,216) $ 45,336 $ 20,079 $ 85 $ — $ 65,500 Equity securities, at fair value (cost $375) 105 106 189 — 400 Real estate investments 1 968 — — 969 Short-term securities 1,645 581 1,868 — 4,094 Other investments 2,772 781 1 — 3,554 Total investments 49,859 22,515 2,143 — 74,517 Cash 150 207 — — 357 Investment income accrued 406 182 3 — 591 Premiums receivable 5,356 2,591 — — 7,947 Reinsurance recoverables 6,496 1,785 — — 8,281 Ceded unearned premiums 838 97 — — 935 Deferred acquisition costs 1,987 203 — — 2,190 Deferred taxes (76 ) 222 (31 ) — 115 Contractholder receivables 4,801 10 — — 4,811 Goodwill 2,581 1,377 — (9 ) 3,949 Other intangible assets 222 119 — — 341 Investment in subsidiaries — — 28,475 (28,475 ) — Other assets 2,470 393 349 — 3,212 Total assets $ 75,090 $ 29,701 $ 30,939 $ (28,484 ) $ 107,246 Liabilities Claims and claim adjustment expense reserves $ 34,800 $ 15,918 $ — $ — $ 50,718 Unearned premium reserves 9,872 4,250 — — 14,122 Contractholder payables 4,801 10 — — 4,811 Payables for reinsurance premiums 380 255 — — 635 Debt 693 — 6,364 — 7,057 Other liabilities 4,287 1,049 227 — 5,563 Total liabilities 54,833 21,482 6,591 — 82,906 Shareholders’ equity Common stock (1,750.0 shares authorized; 262.0 shares issued and 261.9 shares outstanding) — 401 23,243 (401 ) 23,243 Additional paid-in capital 11,634 7,083 — (18,717 ) — Retained earnings 8,390 807 35,803 (9,205 ) 35,795 Accumulated other comprehensive income (loss) 233 (72 ) (682 ) (161 ) (682 ) Treasury stock, at cost (514.2 shares) — — (34,016 ) — (34,016 ) Total shareholders’ equity 20,257 8,219 24,348 (28,484 ) 24,340 Total liabilities and shareholders’ equity $ 75,090 $ 29,701 $ 30,939 $ (28,484 ) $ 107,246 CONSOLIDATING BALANCE SHEET (Unaudited) At December 31, 2018 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Assets Fixed maturities, available for sale, at fair value (amortized cost $63,601) $ 43,683 $ 19,697 $ 84 $ — $ 63,464 Equity securities, available for sale, at fair value (cost $382) 105 92 171 — 368 Real estate investments 2 902 — — 904 Short-term securities 1,855 759 1,371 — 3,985 Other investments 2,746 810 1 — 3,557 Total investments 48,391 22,260 1,627 — 72,278 Cash 181 192 — — 373 Investment income accrued 434 187 3 — 624 Premiums receivable 5,089 2,417 — — 7,506 Reinsurance recoverables 5,904 2,466 — — 8,370 Ceded unearned premiums 522 56 — — 578 Deferred acquisition costs 1,930 190 — — 2,120 Deferred taxes 167 302 (24 ) — 445 Contractholder receivables 3,867 918 — — 4,785 Goodwill 2,578 1,368 — (9 ) 3,937 Other intangible assets 224 121 — — 345 Investment in subsidiaries — — 26,993 (26,993 ) — Other assets 2,220 15 669 (32 ) 2,872 Total assets $ 71,507 $ 30,492 $ 29,268 $ (27,034 ) $ 104,233 Liabilities Claims and claim adjustment expense reserves $ 34,093 $ 16,575 $ — $ — $ 50,668 Unearned premium reserves 9,414 4,141 — — 13,555 Contractholder payables 3,867 918 — — 4,785 Payables for reinsurance premiums 169 120 — — 289 Debt 693 32 5,871 (32 ) 6,564 Other liabilities 4,133 849 496 — 5,478 Total liabilities 52,369 22,635 6,367 (32 ) 81,339 Shareholders’ equity Common stock (1,750.0 shares authorized; 263.7 shares issued and 263.6 shares outstanding) — 401 23,144 (401 ) 23,144 Additional paid-in capital 11,634 7,023 — (18,657 ) — Retained earnings 8,065 879 35,211 (8,951 ) 35,204 Accumulated other comprehensive loss (561 ) (446 ) (1,859 ) 1,007 (1,859 ) Treasury stock, at cost (510.9 shares) — — (33,595 ) — (33,595 ) Total shareholders’ equity 19,138 7,857 22,901 (27,002 ) 22,894 Total liabilities and shareholders’ equity $ 71,507 $ 30,492 $ 29,268 $ (27,034 ) $ 104,233 CONSOLIDATING STATEMENT OF CASH FLOWS (Unaudited) For the three months ended March 31, 2019 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Cash flows from operating activities Net income $ 625 $ 208 $ 796 $ (833 ) $ 796 Net adjustments to reconcile net income to net cash provided by operating activities (110 ) (42 ) (227 ) 222 (157 ) Net cash provided by operating activities 515 166 569 (611 ) 639 Cash flows from investing activities Proceeds from maturities of fixed maturities 1,043 508 5 — 1,556 Proceeds from sales of investments: Fixed maturities 551 218 — — 769 Equity securities 19 20 — — 39 Real estate investments — — — — — Other investments 90 15 — — 105 Purchases of investments: Fixed maturities (2,228 ) (682 ) (4 ) — (2,914 ) Equity securities (1 ) (20 ) (1 ) — (22 ) Real estate investments — (77 ) — — (77 ) Other investments (134 ) (12 ) — — (146 ) Net sales (purchases) of short-term securities 210 178 (497 ) — (109 ) Securities transactions in course of settlement 283 13 (1 ) — 295 Other (80 ) (2 ) — — (82 ) Net cash provided by (used in) investing activities (247 ) 159 (498 ) — (586 ) Cash flows from financing activities Treasury stock acquired — share repurchase authorization — — (375 ) — (375 ) Treasury stock acquired — net employee share-based compensation — — (46 ) — (46 ) Dividends paid to shareholders — — (205 ) — (205 ) Payment of debt — (32 ) — 32 — Issuance of debt — — 492 — 492 Issuance of common stock — employee share options — — 63 — 63 Dividends paid to parent company (300 ) (279 ) — 579 — Net cash used in financing activities (300 ) (311 ) (71 ) 611 (71 ) Effect of exchange rate changes on cash 1 1 — — 2 Net increase (decrease) in cash (31 ) 15 — — (16 ) Cash at beginning of year 181 192 — — 373 Cash at end of period $ 150 $ 207 $ — $ — $ 357 Supplemental disclosure of cash flow information Income taxes paid $ 4 $ 1 $ — $ — $ 5 Interest paid $ 16 $ — $ 34 $ — $ 50 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

Basis of Presentation and Acc_2

Basis of Presentation and Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
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, 2018 (the Company’s 2018 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.
Adoption of Accounting Standards [Policy Text Block]	Adoption of Accounting Standards Leases Effective for the quarter ended March 31, 2019, the Company adopted the updated guidance for leases and elected to utilize a cumulative-effect adjustment to the opening balance of retained earnings for the year of adoption. Accordingly, the Company’s reporting for the comparative periods prior to adoption continue to be presented in the financial statements in accordance with previous lease accounting guidance. The Company also elected to apply all practical expedients applicable to the Company in the updated guidance for transition for leases in effect at adoption, including using hindsight to determine the lease term of existing leases, the option to not reassess whether an existing contract is a lease or contains a lease and whether the lease is an operating or finance lease. The adoption of the updated guidance resulted in the Company recognizing a right-of-use asset of $320 million as part of other assets and a lease liability of $384 million as part of other liabilities in the consolidated balance sheet, as well as de-recognizing the liability for deferred rent that was required under the previous guidance, for its corporate real estate agreements at March 31, 2019. The cumulative effect adjustment to the opening balance of retained earnings was zero . The adoption of the updated guidance did not have a material effect on the Company’s results of operations or liquidity. Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract Effective for the quarter ended March 31, 2019, the Company adopted the updated guidance regarding Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract , and applied the guidance prospectively. The updated guidance requires an entity to determine the stage of a project that the implementation activity relates to and the nature of the associated costs in order to determine whether those costs should be expensed as incurred or capitalized. The updated guidance also requires the entity to amortize the capitalized implementation costs as an expense over the term of the hosting arrangement. The adoption of the updated guidance did not have a material effect on the Company’s results of operations, financial position or liquidity. For additional information regarding accounting standards that the Company adopted during the periods presented, see note 1 of notes to the consolidated financial statements in the Company’s 2018 Annual Report.

Segment Information (Tables)

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2019
Segment Reporting [Abstract]
Company's revenues and income by segment [Table Text Block]	(For the three months ended March 31, in millions) Business Insurance Bond & Specialty Insurance Personal Insurance Total Reportable Segments 2019 Premiums $ 3,742 $ 606 $ 2,507 $ 6,855 Net investment income 427 56 99 582 Fee income 104 — 5 109 Other revenues 43 6 22 71 Total segment revenues (1) $ 4,316 $ 668 $ 2,633 $ 7,617 Segment income (1) $ 414 $ 138 $ 278 $ 830 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 _________________________________________________________ (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) 2019 2018 Revenue reconciliation Earned premiums Business Insurance: Domestic: Workers’ compensation $ 972 $ 971 Commercial automobile 628 562 Commercial property 460 438 General liability 567 521 Commercial multi-peril 840 805 Other 8 7 Total Domestic 3,475 3,304 International 267 264 Total Business Insurance 3,742 3,568 Bond & Specialty Insurance: Domestic: Fidelity and surety 246 246 General liability 257 242 Other 52 47 Total Domestic 555 535 International 51 47 Total Bond & Specialty Insurance 606 582 Personal Insurance: Domestic: Automobile 1,297 1,225 Homeowners and Other 1,039 995 Total Domestic 2,336 2,220 International 171 167 Total Personal Insurance 2,507 2,387 Total earned premiums 6,855 6,537 Net investment income 582 603 Fee income 109 103 Other revenues 71 54 Total segment revenues 7,617 7,297 Other revenues 1 — Net realized investment gains (losses) 53 (11 ) Total revenues $ 7,671 $ 7,286 Income reconciliation, net of tax Total segment income $ 830 $ 754 Interest Expense and Other (1) (75 ) (76 ) Core income 755 678 Net realized investment gains (losses) 41 (9 ) Net income $ 796 $ 669 _________________________________________________________ (1) The primary component of Interest Expense and Other was after-tax interest expense of $70 million for both the three months ended March 31, 2019 and 2018 .
Asset reconciliation [Table Text Block]	(in millions) March 31, December 31, Asset reconciliation Business Insurance $ 82,022 $ 78,965 Bond & Specialty Insurance 8,363 8,693 Personal Insurance 16,288 15,943 Total assets by reportable segment 106,673 103,601 Other assets (1) 573 632 Total consolidated assets $ 107,246 $ 104,233 _________________________________________________________ (1) The primary components of other assets at both March 31, 2019 and December 31, 2018 were accrued over-funded benefit plan assets related to the Company’s qualified domestic pension plan and other intangible assets.

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2019
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, 2019, in millions) Cost Gains Losses Value U.S. Treasury securities and obligations of U.S. government and government agencies and authorities $ 2,029 $ 7 $ 6 $ 2,030 Obligations of states, municipalities and political subdivisions: Local general obligation 14,879 468 14 15,333 Revenue 9,757 336 8 10,085 State general obligation 1,300 37 2 1,335 Pre-refunded 2,515 79 — 2,594 Total obligations of states, municipalities and political subdivisions 28,451 920 24 29,347 Debt securities issued by foreign governments 1,184 12 2 1,194 Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 2,601 64 16 2,649 All other corporate bonds 29,873 482 156 30,199 Redeemable preferred stock 78 3 — 81 Total $ 64,216 $ 1,488 $ 204 $ 65,500 Amortized Gross Unrealized Fair (at December 31, 2018, in millions) Cost Gains Losses Value U.S. Treasury securities and obligations of U.S. government and government agencies and authorities $ 2,076 $ 4 $ 16 $ 2,064 Obligations of states, municipalities and political subdivisions: Local general obligation 14,473 219 120 14,572 Revenue 9,755 172 74 9,853 State general obligation 1,329 18 13 1,334 Pre-refunded 2,772 80 — 2,852 Total obligations of states, municipalities and political subdivisions 28,329 489 207 28,611 Debt securities issued by foreign governments 1,255 7 5 1,257 Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 2,557 54 38 2,573 All other corporate bonds 29,307 156 583 28,880 Redeemable preferred stock 77 2 — 79 Total $ 63,601 $ 712 $ 849 $ 63,464
Cost and fair value of investments in equity securities [Table Text Block]	The cost and fair value of investments in equity securities were as follows: Fair (at March 31, 2019, in millions) Cost Gross Gains Gross Losses Value Public common stock $ 339 $ 24 $ 6 $ 357 Non-redeemable preferred stock 36 7 — 43 Total $ 375 $ 31 $ 6 $ 400 Fair (at December 31, 2018, in millions) Cost Gross Gains Gross Losses Value Public common stock $ 338 $ 2 $ 24 $ 316 Non-redeemable preferred stock 44 8 — 52 Total $ 382 $ 10 $ 24 $ 368
Unrealized investment losses [Table Text Block]	The following tables summarize, for all investments in an unrealized loss position at March 31, 2019 and December 31, 2018 , 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 2018 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 2018 Annual Report to determine whether such investments are other-than-temporarily impaired. Less than 12 months 12 months or longer Total (at March 31, 2019, 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 $ 51 $ — $ 1,056 $ 6 $ 1,107 $ 6 Obligations of states, municipalities and political subdivisions 103 — 2,464 24 2,567 24 Debt securities issued by foreign governments 15 — 255 2 270 2 Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 32 — 1,333 16 1,365 16 All other corporate bonds 551 7 9,622 149 10,173 156 Total fixed maturities $ 752 $ 7 $ 14,730 $ 197 $ 15,482 $ 204 Less than 12 months 12 months or longer Total (at December 31, 2018, 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 $ 484 $ 5 $ 1,011 $ 11 $ 1,495 $ 16 Obligations of states, municipalities and political subdivisions 5,241 82 3,298 125 8,539 207 Debt securities issued by foreign governments 96 — 328 5 424 5 Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 593 9 1,070 29 1,663 38 All other corporate bonds 12,622 303 6,872 280 19,494 583 Total fixed maturities $ 19,036 $ 399 $ 12,579 $ 450 $ 31,615 $ 849

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2019
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. (at March 31, 2019, 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 $ 2,030 $ 2,030 $ — $ — Obligations of states, municipalities and political subdivisions 29,347 — 29,335 12 Debt securities issued by foreign governments 1,194 — 1,194 — Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 2,649 — 2,649 — All other corporate bonds 30,199 4 30,092 103 Redeemable preferred stock 81 3 78 — Total fixed maturities 65,500 2,037 63,348 115 Equity securities Public common stock 357 356 1 — Non-redeemable preferred stock 43 14 29 — Total equity securities 400 370 30 — Other investments 58 16 — 42 Total $ 65,958 $ 2,423 $ 63,378 $ 157 Other liabilities $ 10 $ — $ — $ 10 (at December 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 $ 2,064 $ 2,064 $ — $ — Obligations of states, municipalities and political subdivisions 28,611 — 28,599 12 Debt securities issued by foreign governments 1,257 — 1,257 — Mortgage-backed securities, collateralized mortgage obligations and pass-through securities 2,573 — 2,554 19 All other corporate bonds 28,880 — 28,725 155 Redeemable preferred stock 79 3 76 — Total fixed maturities 63,464 2,067 61,211 186 Equity securities Public common stock 316 316 — — Non-redeemable preferred stock 52 30 22 — Total equity securities 368 346 22 — Other investments 52 16 — 36 Total $ 63,884 $ 2,429 $ 61,233 $ 222 Other liabilities $ 10 $ — $ — $ 10
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, 2019, in millions) Carrying Value Fair Value Level 1 Level 2 Level 3 Financial assets Short-term securities $ 4,094 $ 4,094 $ 483 $ 3,567 $ 44 Financial liabilities Debt $ 6,957 $ 7,984 $ — $ 7,984 $ — Commercial paper $ 100 $ 100 $ — $ 100 $ — (at December 31, 2018, in millions) Carrying Value Fair Value Level 1 Level 2 Level 3 Financial assets Short-term securities $ 3,985 $ 3,985 $ 632 $ 3,316 $ 37 Financial liabilities Debt $ 6,464 $ 7,128 $ — $ 7,128 $ — Commercial paper $ 100 $ 100 $ — $ 100 $ —

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2019
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 $ 2,594 $ 2,585 Bond & Specialty Insurance 550 550 Personal Insurance 779 776 Other 26 26 Total $ 3,949 $ 3,937
Other intangible assets subject to amortization [Table Text Block]	The following tables present a summary of the Company’s other intangible assets by major asset class. (at March 31, 2019, in millions) Gross Carrying Amount Accumulated Amortization Net Subject to amortization Customer-related $ 100 $ 15 $ 85 Contract-based (1) 204 174 30 Total subject to amortization 304 189 115 Not subject to amortization 226 — 226 Total $ 530 $ 189 $ 341 (at December 31, 2018, in millions) Gross Carrying Amount Accumulated Amortization Net Subject to amortization Customer-related $ 98 $ 12 $ 86 Contract-based (1) 208 175 33 Total subject to amortization 306 187 119 Not subject to amortization 226 — 226 Total $ 532 $ 187 $ 345 _________________________________________________________ (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]	The following tables present a summary of the Company’s other intangible assets by major asset class. (at March 31, 2019, in millions) Gross Carrying Amount Accumulated Amortization Net Subject to amortization Customer-related $ 100 $ 15 $ 85 Contract-based (1) 204 174 30 Total subject to amortization 304 189 115 Not subject to amortization 226 — 226 Total $ 530 $ 189 $ 341 (at December 31, 2018, in millions) Gross Carrying Amount Accumulated Amortization Net Subject to amortization Customer-related $ 98 $ 12 $ 86 Contract-based (1) 208 175 33 Total subject to amortization 306 187 119 Not subject to amortization 226 — 226 Total $ 532 $ 187 $ 345 _________________________________________________________ (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, 2019
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 $ 50,704 $ 50,653 Accident and health 14 15 Total $ 50,718 $ 50,668
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: Three Months Ended (in millions) 2019 2018 Claims and claim adjustment expense reserves at beginning of year $ 50,653 $ 49,633 Less reinsurance recoverables on unpaid losses 8,182 8,123 Net reserves at beginning of year 42,471 41,510 Estimated claims and claim adjustment expenses for claims arising in the current year 4,435 4,391 Estimated decrease in claims and claim adjustment expenses for claims arising in prior years (16 ) (116 ) Total increases 4,419 4,275 Claims and claim adjustment expense payments for claims arising in: Current year 970 1,009 Prior years 3,320 3,040 Total payments 4,290 4,049 Unrealized foreign exchange (gain) loss 41 (10 ) Net reserves at end of period 42,641 41,726 Plus reinsurance recoverables on unpaid losses 8,063 8,068 Claims and claim adjustment expense reserves at end of period $ 50,704 $ 49,794

Other Comprehensive Income an_2

Other Comprehensive Income and Accumulated Other Comprehensive Income (Tables)	3 Months Ended
	Mar. 31, 2019
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, 2019 . Changes in Net Unrealized Gains (Losses) 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, 2018 $ (306 ) $ 193 $ (873 ) $ (873 ) $ (1,859 ) Other comprehensive income (OCI) before reclassifications, net of tax 1,129 4 — 47 1,180 Amounts reclassified from AOCI, net of tax (13 ) — 10 — (3 ) Net OCI, current period 1,116 4 10 47 1,177 Balance, March 31, 2019 $ 810 $ 197 $ (863 ) $ (826 ) $ (682 )
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) 2019 2018 Changes in net unrealized gains (losses) on investment securities: Having no credit losses recognized in the consolidated statement of income $ 1,416 $ (1,203 ) Income tax expense (benefit) 300 (253 ) Net of taxes 1,116 (950 ) Having credit losses recognized in the consolidated statement of income 5 (2 ) Income tax expense (benefit) 1 (1 ) Net of taxes 4 (1 ) Net changes in benefit plan assets and obligations 12 22 Income tax expense 2 5 Net of taxes 10 17 Net changes in unrealized foreign currency translation 50 6 Income tax expense 3 5 Net of taxes 47 1 Total other comprehensive income (loss) 1,483 (1,177 ) Total income tax expense (benefit) 306 (244 ) Total other comprehensive income (loss), net of taxes $ 1,177 $ (933 )
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) 2019 2018 Reclassification adjustments related to unrealized gains (losses) on investment securities: Having no credit losses recognized in the consolidated statement of income (1) $ (16 ) $ — Income tax expense (2) (3 ) — Net of taxes (13 ) — 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) 5 9 General and administrative expenses (3) 8 13 Total 13 22 Income tax benefit (2) 3 5 Net of taxes 10 17 Reclassification adjustment related to foreign currency translation (1) — — Income tax benefit (2) — — Net of taxes — — Total reclassifications (3 ) 22 Total income tax (expense) benefit — 5 Total reclassifications, net of taxes $ (3 ) $ 17 _________________________________________________________ (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, 2019
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) 2019 2018 Basic and Diluted Net income, as reported $ 796 $ 669 Participating share-based awards — allocated income (5 ) (5 ) Net income available to common shareholders — basic and diluted $ 791 $ 664 Common Shares Basic Weighted average shares outstanding 262.9 271.0 Diluted Weighted average shares outstanding 262.9 271.0 Weighted average effects of dilutive securities — stock options and performance shares 1.9 2.9 Total 264.8 273.9 Net Income per Common Share Basic $ 3.01 $ 2.45 Diluted $ 2.99 $ 2.42

Share-Based Incentive Compens_2

Share-Based Incentive Compensation (Table)	3 Months Ended
	Mar. 31, 2019
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, 2019 : Stock Options Number Weighted Average Exercise Price Weighted Average Contractual Life Remaining Aggregate Intrinsic Value ($ in millions) Vested at end of period (1) 7,029,165 $ 103.80 5.8 years $ 237 Exercisable at end of period 5,124,196 $ 94.88 4.7 years $ 217 _________________________________________________________ (1) Represents awards for which the requisite service has been rendered, including those that are retirement eligible.

Pension Plans, Retirement Ben_2

Pension Plans, Retirement Benefits and Savings Plans (Tables)	3 Months Ended
	Mar. 31, 2019
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, 2019 and 2018 . Pension Plans Postretirement Benefit Plans (for the three months ended March 31, in millions) 2019 2018 2019 2018 Net Periodic Benefit Cost: Service cost $ 30 $ 33 $ — $ — Non-service cost: Interest cost on benefit obligation 35 31 2 2 Expected return on plan assets (69 ) (66 ) — — Amortization of unrecognized: Prior service benefit — — (1 ) (1 ) Net actuarial loss 14 23 — — Total non-service cost (benefit) (20 ) (12 ) 1 1 Net periodic benefit cost $ 10 $ 21 $ 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 cost (benefit) are presented in the consolidated statement of income for the three months ended March 31, 2019 and 2018 . Pension Plans Postretirement Benefit Plans (for the three months ended March 31, in millions) 2019 2018 2019 2018 Service Cost: Claims and claim adjustment expenses $ 12 $ 13 $ — $ — General and administrative expenses 18 20 — — Total service cost 30 33 — — Non-Service Cost (Benefit): Claims and claim adjustment expenses (8 ) (5 ) — — General and administrative expenses (12 ) (7 ) 1 1 Total non-service cost (benefit) (20 ) (12 ) 1 1 Net periodic benefit cost $ 10 $ 21 $ 1 $ 1

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2019
Leases [Abstract]
Additional information regarding real estate operating leases	Lease expense is included in general and administrative expenses in the consolidated statement of income. Additional information regarding the Company’s real estate operating leases is as follows: (in millions) Three Months Ended Lease cost Operating leases $ 22 Short-term leases (1) 4 Lease expense 26 Less: sublease income (2) — Net lease cost $ 26 Other information on operating leases Cash payments included in the measurement of lease liabilities reported in operating cash flows $ 24 Right-of-use assets obtained in exchange for new lease liabilities $ 8 Weighted average discount rate 3.07 % Weighted average remaining lease term in years 5.2 years _________________________________________________________ (1) Leases with an initial term of twelve months or less are not recorded on the balance sheet. (2) Sublease income consists of rent from third parties of office space and is recognized as part of other revenues in the consolidated statement of income.
Contractual maturities of lease liabilities	The following table presents the contractual maturities of the Company's lease liabilities: (in millions) Real Estate Lease Liability Remainder of 2019 $ 73 2020 95 2021 82 2022 61 2023 41 Thereafter 62 Total undiscounted lease payments 414 Less: present value adjustment 30 Operating lease liability $ 384

Consolidating Financial State_2

Consolidating Financial Statements (Unaudited) (Tables)	3 Months Ended
	Mar. 31, 2019
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, 2019 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Revenues Premiums $ 4,689 $ 2,166 $ — $ — $ 6,855 Net investment income 416 155 11 — 582 Fee income 109 — — — 109 Net realized investment gains (1) 22 15 16 — 53 Other revenues 38 34 — — 72 Total revenues 5,274 2,370 27 — 7,671 Claims and expenses Claims and claim adjustment expenses 3,024 1,418 — — 4,442 Amortization of deferred acquisition costs 745 372 — — 1,117 General and administrative expenses 722 330 5 — 1,057 Interest expense 12 — 76 — 88 Total claims and expenses 4,503 2,120 81 — 6,704 Income (loss) before income taxes 771 250 (54 ) — 967 Income tax expense (benefit) 146 42 (17 ) — 171 Net income of subsidiaries — — 833 (833 ) — Net income $ 625 $ 208 $ 796 $ (833 ) $ 796 ____________________________________________________ (1) Total other-than-temporary impairments (OTTI) for the three months ended March 31, 2019 , and the amounts comprising total OTTI that were recognized in net realized investment gains 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 $ (1 ) $ — $ — $ — $ (1 ) OTTI losses recognized in OCI $ — $ — $ — $ — $ — 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 Comprehensive Income (Loss) (Unaudited) [Table Text Block]	CONSOLIDATING STATEMENT OF COMPREHENSIVE INCOME (Unaudited) For the three months ended March 31, 2019 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Net income $ 625 $ 208 $ 796 $ (833 ) $ 796 Other comprehensive income: Changes in net unrealized gains (losses) on investment securities: Having no credit losses recognized in the consolidated statement of income 979 435 2 — 1,416 Having credit losses recognized in the consolidated statement of income 4 1 — — 5 Net changes in benefit plan assets and obligations — — 12 — 12 Net changes in unrealized foreign currency translation 19 31 — — 50 Other comprehensive income before income taxes and other comprehensive income of subsidiaries 1,002 467 14 — 1,483 Income tax expense 208 93 5 — 306 Other comprehensive income, net of taxes, before other comprehensive income of subsidiaries 794 374 9 — 1,177 Other comprehensive income of subsidiaries — — 1,168 (1,168 ) — Other comprehensive income 794 374 1,177 (1,168 ) 1,177 Comprehensive income $ 1,419 $ 582 $ 1,973 $ (2,001 ) $ 1,973 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 (losses) 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 Balance Sheet (Unaudited) [Table Text Block]	CONSOLIDATING BALANCE SHEET (Unaudited) At March 31, 2019 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Assets Fixed maturities, available for sale, at fair value (amortized cost $64,216) $ 45,336 $ 20,079 $ 85 $ — $ 65,500 Equity securities, at fair value (cost $375) 105 106 189 — 400 Real estate investments 1 968 — — 969 Short-term securities 1,645 581 1,868 — 4,094 Other investments 2,772 781 1 — 3,554 Total investments 49,859 22,515 2,143 — 74,517 Cash 150 207 — — 357 Investment income accrued 406 182 3 — 591 Premiums receivable 5,356 2,591 — — 7,947 Reinsurance recoverables 6,496 1,785 — — 8,281 Ceded unearned premiums 838 97 — — 935 Deferred acquisition costs 1,987 203 — — 2,190 Deferred taxes (76 ) 222 (31 ) — 115 Contractholder receivables 4,801 10 — — 4,811 Goodwill 2,581 1,377 — (9 ) 3,949 Other intangible assets 222 119 — — 341 Investment in subsidiaries — — 28,475 (28,475 ) — Other assets 2,470 393 349 — 3,212 Total assets $ 75,090 $ 29,701 $ 30,939 $ (28,484 ) $ 107,246 Liabilities Claims and claim adjustment expense reserves $ 34,800 $ 15,918 $ — $ — $ 50,718 Unearned premium reserves 9,872 4,250 — — 14,122 Contractholder payables 4,801 10 — — 4,811 Payables for reinsurance premiums 380 255 — — 635 Debt 693 — 6,364 — 7,057 Other liabilities 4,287 1,049 227 — 5,563 Total liabilities 54,833 21,482 6,591 — 82,906 Shareholders’ equity Common stock (1,750.0 shares authorized; 262.0 shares issued and 261.9 shares outstanding) — 401 23,243 (401 ) 23,243 Additional paid-in capital 11,634 7,083 — (18,717 ) — Retained earnings 8,390 807 35,803 (9,205 ) 35,795 Accumulated other comprehensive income (loss) 233 (72 ) (682 ) (161 ) (682 ) Treasury stock, at cost (514.2 shares) — — (34,016 ) — (34,016 ) Total shareholders’ equity 20,257 8,219 24,348 (28,484 ) 24,340 Total liabilities and shareholders’ equity $ 75,090 $ 29,701 $ 30,939 $ (28,484 ) $ 107,246 CONSOLIDATING BALANCE SHEET (Unaudited) At December 31, 2018 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Assets Fixed maturities, available for sale, at fair value (amortized cost $63,601) $ 43,683 $ 19,697 $ 84 $ — $ 63,464 Equity securities, available for sale, at fair value (cost $382) 105 92 171 — 368 Real estate investments 2 902 — — 904 Short-term securities 1,855 759 1,371 — 3,985 Other investments 2,746 810 1 — 3,557 Total investments 48,391 22,260 1,627 — 72,278 Cash 181 192 — — 373 Investment income accrued 434 187 3 — 624 Premiums receivable 5,089 2,417 — — 7,506 Reinsurance recoverables 5,904 2,466 — — 8,370 Ceded unearned premiums 522 56 — — 578 Deferred acquisition costs 1,930 190 — — 2,120 Deferred taxes 167 302 (24 ) — 445 Contractholder receivables 3,867 918 — — 4,785 Goodwill 2,578 1,368 — (9 ) 3,937 Other intangible assets 224 121 — — 345 Investment in subsidiaries — — 26,993 (26,993 ) — Other assets 2,220 15 669 (32 ) 2,872 Total assets $ 71,507 $ 30,492 $ 29,268 $ (27,034 ) $ 104,233 Liabilities Claims and claim adjustment expense reserves $ 34,093 $ 16,575 $ — $ — $ 50,668 Unearned premium reserves 9,414 4,141 — — 13,555 Contractholder payables 3,867 918 — — 4,785 Payables for reinsurance premiums 169 120 — — 289 Debt 693 32 5,871 (32 ) 6,564 Other liabilities 4,133 849 496 — 5,478 Total liabilities 52,369 22,635 6,367 (32 ) 81,339 Shareholders’ equity Common stock (1,750.0 shares authorized; 263.7 shares issued and 263.6 shares outstanding) — 401 23,144 (401 ) 23,144 Additional paid-in capital 11,634 7,023 — (18,657 ) — Retained earnings 8,065 879 35,211 (8,951 ) 35,204 Accumulated other comprehensive loss (561 ) (446 ) (1,859 ) 1,007 (1,859 ) Treasury stock, at cost (510.9 shares) — — (33,595 ) — (33,595 ) Total shareholders’ equity 19,138 7,857 22,901 (27,002 ) 22,894 Total liabilities and shareholders’ equity $ 71,507 $ 30,492 $ 29,268 $ (27,034 ) $ 104,233
Consolidating Statement of Cash Flows (Unaudited) [Table Text Block]	CONSOLIDATING STATEMENT OF CASH FLOWS (Unaudited) For the three months ended March 31, 2019 (in millions) TPC Other Subsidiaries TRV Eliminations Consolidated Cash flows from operating activities Net income $ 625 $ 208 $ 796 $ (833 ) $ 796 Net adjustments to reconcile net income to net cash provided by operating activities (110 ) (42 ) (227 ) 222 (157 ) Net cash provided by operating activities 515 166 569 (611 ) 639 Cash flows from investing activities Proceeds from maturities of fixed maturities 1,043 508 5 — 1,556 Proceeds from sales of investments: Fixed maturities 551 218 — — 769 Equity securities 19 20 — — 39 Real estate investments — — — — — Other investments 90 15 — — 105 Purchases of investments: Fixed maturities (2,228 ) (682 ) (4 ) — (2,914 ) Equity securities (1 ) (20 ) (1 ) — (22 ) Real estate investments — (77 ) — — (77 ) Other investments (134 ) (12 ) — — (146 ) Net sales (purchases) of short-term securities 210 178 (497 ) — (109 ) Securities transactions in course of settlement 283 13 (1 ) — 295 Other (80 ) (2 ) — — (82 ) Net cash provided by (used in) investing activities (247 ) 159 (498 ) — (586 ) Cash flows from financing activities Treasury stock acquired — share repurchase authorization — — (375 ) — (375 ) Treasury stock acquired — net employee share-based compensation — — (46 ) — (46 ) Dividends paid to shareholders — — (205 ) — (205 ) Payment of debt — (32 ) — 32 — Issuance of debt — — 492 — 492 Issuance of common stock — employee share options — — 63 — 63 Dividends paid to parent company (300 ) (279 ) — 579 — Net cash used in financing activities (300 ) (311 ) (71 ) 611 (71 ) Effect of exchange rate changes on cash 1 1 — — 2 Net increase (decrease) in cash (31 ) 15 — — (16 ) Cash at beginning of year 181 192 — — 373 Cash at end of period $ 150 $ 207 $ — $ — $ 357 Supplemental disclosure of cash flow information Income taxes paid $ 4 $ 1 $ — $ — $ 5 Interest paid $ 16 $ — $ 34 $ — $ 50 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

Basis of Presentation and Acc_3

Basis of Presentation and Accounting Policies (Details) - USD ($)	Mar. 31, 2019	Jan. 01, 2019	Dec. 31, 2017
New Accounting Pronouncements
Operating lease liability	$ 384,000,000
Retained earnings [Member]
New Accounting Pronouncements
Cumulative effect adjustment			$ 22,000,000
Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements
Right-of-use asset	320,000,000
Operating lease liability	$ 384,000,000
Accounting Standards Update 2016-02 [Member] | Retained earnings [Member]
New Accounting Pronouncements
Cumulative effect adjustment		$ 0

Basis of Presentation and Acc_4

Basis of Presentation and Accounting Policies (Details) - Reportable Segments	3 Months Ended
	Mar. 31, 2019segment
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, 2019	Mar. 31, 2018
Segment reporting information
Premiums		$ 6,855	$ 6,537
Net investment income		582	603
Fee income		109	103
Other revenues		72	54
Net realized investment gains (losses)	[1]	53	(11)
Total revenues		7,671	7,286
Core income (loss)		755	678
Net realized investment gains (losses), net of tax		41	(9)
Net income		796	669
Reportable Segments [Member]
Segment reporting information
Premiums		6,855	6,537
Net investment income		582	603
Fee income		109	103
Other revenues		71	54
Total segment revenues		7,617	7,297
Core income (loss)		830	754
Reportable Segments [Member] | Business Insurance [Member]
Segment reporting information
Premiums		3,742	3,568
Net investment income		427	446
Fee income		104	99
Other revenues		43	31
Total segment revenues		4,316	4,144
Core income (loss)		414	452
Reportable Segments [Member] | Business Insurance [Member] | Domestic [Member]
Segment reporting information
Premiums		3,475	3,304
Reportable Segments [Member] | Business Insurance [Member] | Domestic [Member] | Workers' compensation [Member]
Segment reporting information
Premiums		972	971
Reportable Segments [Member] | Business Insurance [Member] | Domestic [Member] | Automobile [Member]
Segment reporting information
Premiums		628	562
Reportable Segments [Member] | Business Insurance [Member] | Domestic [Member] | Commercial property [Member]
Segment reporting information
Premiums		460	438
Reportable Segments [Member] | Business Insurance [Member] | Domestic [Member] | General liability [Member]
Segment reporting information
Premiums		567	521
Reportable Segments [Member] | Business Insurance [Member] | Domestic [Member] | Commercial multi-peril [Member]
Segment reporting information
Premiums		840	805
Reportable Segments [Member] | Business Insurance [Member] | Domestic [Member] | Other [Member]
Segment reporting information
Premiums		8	7
Reportable Segments [Member] | Business Insurance [Member] | International [Member]
Segment reporting information
Premiums		267	264
Reportable Segments [Member] | Bond & Specialty Insurance [Member]
Segment reporting information
Premiums		606	582
Net investment income		56	58
Other revenues		6	6
Total segment revenues		668	646
Core income (loss)		138	173
Reportable Segments [Member] | Bond & Specialty Insurance [Member] | Domestic [Member]
Segment reporting information
Premiums		555	535
Reportable Segments [Member] | Bond & Specialty Insurance [Member] | Domestic [Member] | General liability [Member]
Segment reporting information
Premiums		257	242
Reportable Segments [Member] | Bond & Specialty Insurance [Member] | Domestic [Member] | Fidelity and surety [Member]
Segment reporting information
Premiums		246	246
Reportable Segments [Member] | Bond & Specialty Insurance [Member] | Domestic [Member] | Other [Member]
Segment reporting information
Premiums		52	47
Reportable Segments [Member] | Bond & Specialty Insurance [Member] | International [Member]
Segment reporting information
Premiums		51	47
Reportable Segments [Member] | Personal Insurance [Member]
Segment reporting information
Premiums		2,507	2,387
Net investment income		99	99
Fee income		5	4
Other revenues		22	17
Total segment revenues		2,633	2,507
Core income (loss)		278	129
Reportable Segments [Member] | Personal Insurance [Member] | Domestic [Member]
Segment reporting information
Premiums		2,336	2,220
Reportable Segments [Member] | Personal Insurance [Member] | Domestic [Member] | Automobile [Member]
Segment reporting information
Premiums		1,297	1,225
Reportable Segments [Member] | Personal Insurance [Member] | Domestic [Member] | Homeowners and Other [Member]
Segment reporting information
Premiums		1,039	995
Reportable Segments [Member] | Personal Insurance [Member] | International [Member]
Segment reporting information
Premiums		171	167
Other [Member]
Segment reporting information
Other revenues		1
Core income (loss)		(75)	(76)
After-tax interest expense		$ 70	$ 70
[1]	Total other-than-temporary impairment (OTTI) gains (losses) were $(1) million and $0 for the three months ended March 31, 2019 and 2018, respectively. Of total OTTI, credit losses of $(1) million and $0 for the three months ended March 31, 2019 and 2018, respectively, were recognized in net realized investment gains (losses). In addition, unrealized gains (losses) from other changes in total OTTI of $0 for each of the three months ended March 31, 2019 and 2018, respectively, were recognized in other comprehensive income (loss) as part of changes in net unrealized gains (losses) 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, 2019	Dec. 31, 2018
Assets by segment
Total assets	$ 107,246	$ 104,233
Reportable Segments [Member]
Assets by segment
Total assets	106,673	103,601
Reportable Segments [Member] | Business Insurance [Member]
Assets by segment
Total assets	82,022	78,965
Reportable Segments [Member] | Bond & Specialty Insurance [Member]
Assets by segment
Total assets	8,363	8,693
Reportable Segments [Member] | Personal Insurance [Member]
Assets by segment
Total assets	16,288	15,943
Other assets [Member]
Assets by segment
Total assets	$ 573	$ 632

Investments (Details) - Investm

Investments (Details) - Investment Information, Debt Securities - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Investment disclosure details
Fixed maturities, amortized cost	$ 64,216		$ 63,601
Gross unrealized gains	1,488		712
Gross unrealized losses	204		849
Fixed maturities, at fair value	65,500		63,464
Proceeds from sales of fixed maturities classified as available for sale	769	$ 1,085
Gross realized gains	21	6
Gross realized losses	4	$ 6
U.S. Treasury securities and obligations of U.S. government and government agencies and authorities [Member]
Investment disclosure details
Fixed maturities, amortized cost	2,029		2,076
Gross unrealized gains	7		4
Gross unrealized losses	6		16
Fixed maturities, at fair value	2,030		2,064
Obligations of states, municipalities and political subdivisions [Member]
Investment disclosure details
Fixed maturities, amortized cost	28,451		28,329
Gross unrealized gains	920		489
Gross unrealized losses	24		207
Fixed maturities, at fair value	29,347		28,611
Obligations of states, municipalities and political subdivisions, local general obligation [Member]
Investment disclosure details
Fixed maturities, amortized cost	14,879		14,473
Gross unrealized gains	468		219
Gross unrealized losses	14		120
Fixed maturities, at fair value	15,333		14,572
Obligations of states, municipalities and political subdivisions, revenue [Member]
Investment disclosure details
Fixed maturities, amortized cost	9,757		9,755
Gross unrealized gains	336		172
Gross unrealized losses	8		74
Fixed maturities, at fair value	10,085		9,853
Obligations of states, municipalities and political subdivisions, state general obligation [Member]
Investment disclosure details
Fixed maturities, amortized cost	1,300		1,329
Gross unrealized gains	37		18
Gross unrealized losses	2		13
Fixed maturities, at fair value	1,335		1,334
Obligations of states, municipalities and political subdivisions, pre-refunded [Member]
Investment disclosure details
Fixed maturities, amortized cost	2,515		2,772
Gross unrealized gains	79		80
Fixed maturities, at fair value	2,594		2,852
Debt securities issued by foreign governments [Member]
Investment disclosure details
Fixed maturities, amortized cost	1,184		1,255
Gross unrealized gains	12		7
Gross unrealized losses	2		5
Fixed maturities, at fair value	1,194		1,257
Mortgage-backed securities, collateralized mortgage obligations and pass-through securities [Member]
Investment disclosure details
Fixed maturities, amortized cost	2,601		2,557
Gross unrealized gains	64		54
Gross unrealized losses	16		38
Fixed maturities, at fair value	2,649		2,573
All other corporate bonds [Member]
Investment disclosure details
Fixed maturities, amortized cost	29,873		29,307
Gross unrealized gains	482		156
Gross unrealized losses	156		583
Fixed maturities, at fair value	30,199		28,880
Redeemable preferred stock [Member]
Investment disclosure details
Fixed maturities, amortized cost	78		77
Gross unrealized gains	3		2
Fixed maturities, at fair value	$ 81		$ 79

Investments (Details) - Inves_2

Investments (Details) - Investment Information, Equity Securities - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Investment disclosure details
Equity securities, cost	$ 375		$ 382
Gross gains	31		10
Gross losses	6		24
Equity securities, at fair value	400		368
Net recognized gains (losses) on equity securities still held	39	$ (13)
Public common stock [Member]
Investment disclosure details
Equity securities, cost	339		338
Gross gains	24		2
Gross losses	6		24
Equity securities, at fair value	357		316
Non-redeemable preferred stock [Member]
Investment disclosure details
Equity securities, cost	36		44
Gross gains	7		8
Equity securities, at fair value	$ 43		$ 52

Investments (Details) - Inves_3

Investments (Details) - Investment Information, Losses - USD ($)	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Investment disclosure details
Continuous unrealized loss position, less than 12 months, fair value	$ 752,000,000		$ 19,036,000,000
Continuous unrealized loss position, less than 12 months, gross unrealized losses	7,000,000		399,000,000
Continuous unrealized loss position, 12 months or longer, fair value	14,730,000,000		12,579,000,000
Continuous unrealized loss position, 12 months or longer, gross unrealized losses	197,000,000		450,000,000
Continuous unrealized loss position, total, fair value	15,482,000,000		31,615,000,000
Continuous unrealized loss position, total, gross unrealized losses	204,000,000		849,000,000
Impairment charges	1,000,000	$ 0
Cumulative OTTI credit losses recognized for securities held	$ 56,000,000	$ 75,000,000
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
Continuous unrealized loss position, less than 12 months, fair value	$ 51,000,000		484,000,000
Continuous unrealized loss position, less than 12 months, gross unrealized losses			5,000,000
Continuous unrealized loss position, 12 months or longer, fair value	1,056,000,000		1,011,000,000
Continuous unrealized loss position, 12 months or longer, gross unrealized losses	6,000,000		11,000,000
Continuous unrealized loss position, total, fair value	1,107,000,000		1,495,000,000
Continuous unrealized loss position, total, gross unrealized losses	6,000,000		16,000,000
Obligations of states, municipalities and political subdivisions [Member]
Investment disclosure details
Continuous unrealized loss position, less than 12 months, fair value	103,000,000		5,241,000,000
Continuous unrealized loss position, less than 12 months, gross unrealized losses			82,000,000
Continuous unrealized loss position, 12 months or longer, fair value	2,464,000,000		3,298,000,000
Continuous unrealized loss position, 12 months or longer, gross unrealized losses	24,000,000		125,000,000
Continuous unrealized loss position, total, fair value	2,567,000,000		8,539,000,000
Continuous unrealized loss position, total, gross unrealized losses	24,000,000		207,000,000
Debt securities issued by foreign governments [Member]
Investment disclosure details
Continuous unrealized loss position, less than 12 months, fair value	15,000,000		96,000,000
Continuous unrealized loss position, 12 months or longer, fair value	255,000,000		328,000,000
Continuous unrealized loss position, 12 months or longer, gross unrealized losses	2,000,000		5,000,000
Continuous unrealized loss position, total, fair value	270,000,000		424,000,000
Continuous unrealized loss position, total, gross unrealized losses	2,000,000		5,000,000
Mortgage-backed securities, collateralized mortgage obligations and pass-through securities [Member]
Investment disclosure details
Continuous unrealized loss position, less than 12 months, fair value	32,000,000		593,000,000
Continuous unrealized loss position, less than 12 months, gross unrealized losses			9,000,000
Continuous unrealized loss position, 12 months or longer, fair value	1,333,000,000		1,070,000,000
Continuous unrealized loss position, 12 months or longer, gross unrealized losses	16,000,000		29,000,000
Continuous unrealized loss position, total, fair value	1,365,000,000		1,663,000,000
Continuous unrealized loss position, total, gross unrealized losses	16,000,000		38,000,000
All other corporate bonds [Member]
Investment disclosure details
Continuous unrealized loss position, less than 12 months, fair value	551,000,000		12,622,000,000
Continuous unrealized loss position, less than 12 months, gross unrealized losses	7,000,000		303,000,000
Continuous unrealized loss position, 12 months or longer, fair value	9,622,000,000		6,872,000,000
Continuous unrealized loss position, 12 months or longer, gross unrealized losses	149,000,000		280,000,000
Continuous unrealized loss position, total, fair value	10,173,000,000		19,494,000,000
Continuous unrealized loss position, total, gross unrealized losses	$ 156,000,000		$ 583,000,000

Fair Value Measurements (Detail

Fair Value Measurements (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Percent of fixed maturities for which a pricing service estimates fair value	99.00%	99.00%
Fair value of the fixed maturities for which the Company used an internal pricing matrix	$ 96	$ 82
Fair value of the fixed maturities for which the Company received a broker quote	19	104
Estimated fair value of put/call option	$ 10	$ 10

Fair Value Measurements (Deta_2

Fair Value Measurements (Details) - Fair Value Hierarchy - Recurring basis [Member] - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	$ 65,958	$ 63,884
Other liabilities measured on a recurring basis	10	10
Fixed maturities [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	65,500	63,464
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 and financial liabilities are measured
Total invested assets measured on a recurring basis	2,030	2,064
Obligations of states, municipalities and political subdivisions [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	29,347	28,611
Debt securities issued by foreign governments [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	1,194	1,257
Mortgage-backed securities, collateralized mortgage obligations and pass-through securities [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	2,649	2,573
All other corporate bonds [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	30,199	28,880
Redeemable preferred stock [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	81	79
Equity securities [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	400	368
Public common stock [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	357	316
Non-redeemable preferred stock [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	43	52
Other Investments [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	58	52
Level 1 [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	2,423	2,429
Level 1 [Member] | Fixed maturities [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	2,037	2,067
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 and financial liabilities are measured
Total invested assets measured on a recurring basis	2,030	2,064
Level 1 [Member] | All other corporate bonds [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	4
Level 1 [Member] | Redeemable preferred stock [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities 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 and financial liabilities are measured
Total invested assets measured on a recurring basis	370	346
Level 1 [Member] | Public common stock [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	356	316
Level 1 [Member] | Non-redeemable preferred stock [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	14	30
Level 1 [Member] | Other Investments [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	16	16
Level 2 [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	63,378	61,233
Level 2 [Member] | Fixed maturities [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	63,348	61,211
Level 2 [Member] | Obligations of states, municipalities and political subdivisions [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	29,335	28,599
Level 2 [Member] | Debt securities issued by foreign governments [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	1,194	1,257
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 and financial liabilities are measured
Total invested assets measured on a recurring basis	2,649	2,554
Level 2 [Member] | All other corporate bonds [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	30,092	28,725
Level 2 [Member] | Redeemable preferred stock [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	78	76
Level 2 [Member] | Equity securities [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	30	22
Level 2 [Member] | Public common stock [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	1
Level 2 [Member] | Non-redeemable preferred stock [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	29	22
Level 3 [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	157	222
Other liabilities measured on a recurring basis	10	10
Level 3 [Member] | Fixed maturities [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	115	186
Level 3 [Member] | Obligations of states, municipalities and political subdivisions [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	12	12
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 and financial liabilities are measured
Total invested assets measured on a recurring basis		19
Level 3 [Member] | All other corporate bonds [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	103	155
Level 3 [Member] | Other Investments [Member]
Level within the fair value hierarchy at which the Company's financial assets and financial liabilities are measured
Total invested assets measured on a recurring basis	$ 42	$ 36

Fair Value Measurements (Deta_3

Fair Value Measurements (Details) - Financial Instruments - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Financial Instruments
Short-term securities	$ 4,094	$ 3,985
Commercial paper	100	100
Carrying Value [Member]
Financial Instruments
Short-term securities	4,094	3,985
Debt	6,957	6,464
Commercial paper	100	100
Fair Value [Member]
Financial Instruments
Short-term securities	4,094	3,985
Debt	7,984	7,128
Commercial paper	100	100
Fair Value [Member] | Level 1 [Member]
Financial Instruments
Short-term securities	483	632
Fair Value [Member] | Level 2 [Member]
Financial Instruments
Short-term securities	3,567	3,316
Debt	7,984	7,128
Commercial paper	100	100
Fair Value [Member] | Level 3 [Member]
Financial Instruments
Short-term securities	$ 44	$ 37

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets (Details) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Goodwill by segment
Goodwill	$ 3,949	$ 3,937
Reportable Segments [Member] | Business Insurance [Member]
Goodwill by segment
Goodwill	2,594	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	779	776
Other [Member]
Goodwill by segment
Goodwill	$ 26	$ 26

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets (Details) - Other Intangible Assets - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Other intangible assets by major asset class
Intangible assets subject to amortization, gross carrying amount	$ 304		$ 306
Intangible assets subject to amortization, accumulated amortization	189		187
Intangible assets subject to amortization, net	115		119
Intangible assets not subject to amortization	226		226
Total other intangible assets, gross carrying amount	530		532
Total other intangible assets, net	341		345
Amortization expense of intangible assets	4	$ 4
Estimated intangible asset amortization expense, remainder of 2019	12
Estimated intangible asset amortization expense, 2020	15
Estimated intangible asset amortization expense, 2021	14
Estimated intangible asset amortization expense, 2022	13
Estimated intangible asset amortization expense, 2023	12
Customer-related [Member]
Other intangible assets by major asset class
Intangible assets subject to amortization, gross carrying amount	100		98
Intangible assets subject to amortization, accumulated amortization	15		12
Intangible assets subject to amortization, net	85		86
Contract-based [Member]
Other intangible assets by major asset class
Intangible assets subject to amortization, gross carrying amount	204		208
Intangible assets subject to amortization, accumulated amortization	174		175
Intangible assets subject to amortization, net	30		$ 33
Insurance Contracts Acquired in Business Combination [Member]
Other intangible assets by major asset class
Estimated intangible asset amortization expense, remainder of 2019	4
Estimated intangible asset amortization expense, 2020	5
Estimated intangible asset amortization expense, 2021	4
Estimated intangible asset amortization expense, 2022	3
Estimated intangible asset amortization expense, 2023	$ 3

Insurance Claim Reserves (Detai

Insurance Claim Reserves (Details) - Reserve Detail for Claims and Claim Adjustment Expenses - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
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	$ 50,668
Claims and claim adjustment expense reserves at end of period	50,718
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	50,653	$ 49,633
Reinsurance recoverables on unpaid losses	8,182	8,123
Net reserves at beginning of year	42,471	41,510
Estimated claims and claim adjustment expenses for claims arising in the current year	4,435	4,391
Estimated decrease in claims and claim adjustment expenses for claims arising in prior years	(16)	(116)
Total increases	4,419	4,275
Claims and claim adjustment expense payments for claims arising in current year	970	1,009
Claims and claim adjustment expense payments for claims arising in prior years	3,320	3,040
Total payments	4,290	4,049
Unrealized foreign exchange (gain) loss	41	(10)
Net reserves at end of period	42,641	41,726
Reinsurance recoverables on unpaid losses	8,063	8,068
Claims and claim adjustment expense reserves at end of period	50,704	$ 49,794
Amount of increase in gross claims and claim adjustment expense reserves	51
Amount of decrease in reinsurance recoverables on unpaid losses	(119)
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	15
Claims and claim adjustment expense reserves at end of period	$ 14

Insurance Claim Reserves (Det_2

Insurance Claim Reserves (Details) - Prior Year Reserve Development - Property-casualty [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Liability for claims and claim adjustment expense
Net favorable prior year reserve development included in estimated claims and claim adjustment expenses incurred for claims arising in prior years	$ 16	$ 116
Net favorable (unfavorable) prior year reserve development impacting the Company's results of operations	51	150
Accretion expense	12	13
Business Insurance [Member]
Liability for claims and claim adjustment expense
Net favorable (unfavorable) prior year reserve development impacting the Company's results of operations	(21)	66
Bond & Specialty Insurance [Member]
Liability for claims and claim adjustment expense
Net favorable (unfavorable) prior year reserve development impacting the Company's results of operations	3	35
Personal Insurance [Member]
Liability for claims and claim adjustment expense
Net favorable (unfavorable) prior year reserve development impacting the Company's results of operations	$ 69	$ 49

Other Comprehensive Income an_3

Other Comprehensive Income and Accumulated Other Comprehensive Income (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Accumulated other comprehensive income [Roll Forward]
Balance, beginning of year	$ 22,894
Other comprehensive income (loss), net of taxes	1,177	$ (933)
Balance, end of period	24,340	22,979
Pre-tax components of other comprehensive income (loss) and related tax expense (benefit)
Other comprehensive income (loss) before income taxes	1,483	(1,177)
Income tax expense (benefit)	306	(244)
Other comprehensive income (loss), net of taxes	1,177	(933)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated other comprehensive income [Roll Forward]
Balance, beginning of year	(1,859)	(343)
Other comprehensive income (loss) before reclassifications	1,180
Amounts reclassified from accumulated other comprehensive income	(3)
Other comprehensive income (loss), net of taxes	1,177	(933)
Balance, end of period	(682)	(1,322)
Pre-tax components of other comprehensive income (loss) and related tax expense (benefit)
Other comprehensive income (loss) before income taxes	1,483	(1,177)
Income tax expense (benefit)	306	(244)
Other comprehensive income (loss), net of taxes	1,177	(933)
Changes in Net Unrealized Gains (Losses) 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	(306)
Other comprehensive income (loss) before reclassifications	1,129
Amounts reclassified from accumulated other comprehensive income	(13)
Other comprehensive income (loss), net of taxes	1,116	(950)
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	1,416	(1,203)
Income tax expense (benefit)	300	(253)
Other comprehensive income (loss), net of taxes	1,116	(950)
Changes in Net Unrealized Gains (Losses) on Investment Securities Having Credit Losses Recognized in the Consolidated Statement of Income [Member]
Accumulated other comprehensive income [Roll Forward]
Balance, beginning of year	193
Other comprehensive income (loss) before reclassifications	4
Other comprehensive income (loss), net of taxes	4	(1)
Balance, end of period	197
Pre-tax components of other comprehensive income (loss) and related tax expense (benefit)
Other comprehensive income (loss) before income taxes	5	(2)
Income tax expense (benefit)	1	(1)
Other comprehensive income (loss), net of taxes	4	(1)
Net Benefit Plan Assets and Obligations Recognized in Shareholders' Equity [Member]
Accumulated other comprehensive income [Roll Forward]
Balance, beginning of year	(873)
Amounts reclassified from accumulated other comprehensive income	10
Other comprehensive income (loss), net of taxes	10	17
Balance, end of period	(863)
Pre-tax components of other comprehensive income (loss) and related tax expense (benefit)
Other comprehensive income (loss) before income taxes	12	22
Income tax expense (benefit)	2	5
Other comprehensive income (loss), net of taxes	10	17
Net Unrealized Foreign Currency Translation [Member]
Accumulated other comprehensive income [Roll Forward]
Balance, beginning of year	(873)
Other comprehensive income (loss) before reclassifications	47
Other comprehensive income (loss), net of taxes	47	1
Balance, end of period	(826)
Pre-tax components of other comprehensive income (loss) and related tax expense (benefit)
Other comprehensive income (loss) before income taxes	50	6
Income tax expense (benefit)	3	5
Other comprehensive income (loss), net of taxes	$ 47	$ 1

Other Comprehensive Income an_4

Other Comprehensive Income and Accumulated Other Comprehensive Income (Details) - Reclassifications - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Reclassification Adjustment out of Accumulated Other Comprehensive Income
Reclassification adjustment impacting net realized investment gains (losses) on the income statement	[1]	$ (53)	$ 11
Reclassification adjustment impacting claims and claim adjustment expenses on the income statement		4,442	4,296
Reclassification adjustment impacting general and administrative expense on the income statement		1,057	1,062
Total reclassifications		(967)	(778)
Income tax (expense) benefit		(171)	(109)
Amounts reclassified from accumulated other comprehensive income, net of taxes		(796)	(669)
Accumulated Other Comprehensive Income (Loss) [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income
Total reclassifications		(3)	22
Income tax (expense) benefit			5
Amounts reclassified from accumulated other comprehensive income, net of taxes		(3)	17
Changes in Net Unrealized Gains (Losses) 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		(16)
Income tax (expense) benefit		(3)
Amounts reclassified from accumulated other comprehensive income, net of taxes		(13)
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		5	9
Reclassification adjustment impacting general and administrative expense on the income statement		8	13
Total reclassifications		13	22
Income tax (expense) benefit		3	5
Amounts reclassified from accumulated other comprehensive income, net of taxes		$ 10	$ 17
[1]	Total other-than-temporary impairment (OTTI) gains (losses) were $(1) million and $0 for the three months ended March 31, 2019 and 2018, respectively. Of total OTTI, credit losses of $(1) million and $0 for the three months ended March 31, 2019 and 2018, respectively, were recognized in net realized investment gains (losses). In addition, unrealized gains (losses) from other changes in total OTTI of $0 for each of the three months ended March 31, 2019 and 2018, respectively, were recognized in other comprehensive income (loss) as part of changes in net unrealized gains (losses) on investment securities having credit losses recognized in the consolidated statement of income.

Debt (Details)

Debt (Details) - USD ($)	Mar. 04, 2019	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Debt Instrument
Net proceeds of issuance, after the deduction of the underwriting discount and expenses		$ 492,000,000	$ 491,000,000
Commercial paper outstanding		$ 100,000,000		$ 100,000,000
Senior Notes [Member] | 4.10% Senior notes due March 4, 2049 [Member]
Debt Instrument
Debt, principal amount	$ 500,000,000
Interest rate (percent)	4.10%
Net proceeds of issuance, after the deduction of the underwriting discount and expenses	$ 492,000,000
Percentage of principal amount at which redemption price may be set	100.00%
Basis points added to current Treasury rate used in calculation of alternative redemption price	0.20%

Common Share Repurchases (Detai

Common Share Repurchases (Details) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)$ / sharesshares
Treasury Stock Transactions, Excluding Value of Shares Reissued [Abstract]
Number of shares repurchased (in shares) | shares	2.9
Cost of shares repurchased	$ 375
Average cost per share repurchased (in dollars per share) | $ / shares	$ 129.42
Number of shares acquired to cover tax withholding costs and exercise costs (in shares) | shares	0.4
Cost of shares acquired to cover tax withholding costs and exercise costs	$ 46
Remaining capacity under share repurchase authorization	$ 2,910

Earnings per Share (Details)

Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Earnings Per Share Reconciliation [Abstract]
Net income	$ 796	$ 669
Participating share-based awards — allocated income	(5)	(5)
Net income available to common shareholders -- basic	791	664
Net income available to common shareholders -- diluted	$ 791	$ 664
Weighted average shares outstanding, basic (in shares)	262.9	271
Weighted average effects of dilutive securities - stock options and performance shares (in shares)	1.9	2.9
Weighted average shares outstanding, diluted (in shares)	264.8	273.9
Net income per common share, basic (in dollars per share)	$ 3.01	$ 2.45
Net income per common share, diluted (in dollars per share)	$ 2.99	$ 2.42

Share-Based Incentive Compens_3

Share-Based Incentive Compensation (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock options vested at end of period, number (in shares)	7,029,165
Stock options vested at end of period, weighted average exercise price (in dollars per share)	$ 103.80
Stock options vested at end of period, weighted average contractual life remaining (in years)	5 years 9 months 18 days
Stock options vested at end of period, aggregate intrinsic value	$ 237
Stock options exercisable at end of period, number (in shares)	5,124,196
Stock options exercisable at end of period, weighted average exercise price (in dollars per share)	$ 94.88
Stock options exercisable at end of period, weighted average contractual life remaining (in years)	4 years 8 months 12 days
Stock options exercisable at end of period, aggregate intrinsic value	$ 217
Total compensation cost recognized in earnings for all share-based incentive compensation awards	45	$ 44
Tax benefit recognized in earnings related to compensation costs	8	$ 8
Total unrecognized compensation cost related to all nonvested share-based incentive compensation awards	$ 235
Weighted-average period of recognition for unrecognized compensation cost (in years)	2 years 2 months 12 days

Pension Plans, Retirement Ben_3

Pension Plans, Retirement Benefits and Savings Plans (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Pension Plans [Member]
Defined benefit plan disclosure
Service cost	$ 30	$ 33
Interest cost on benefit obligation	35	31
Expected return on plan assets	(69)	(66)
Net periodic benefit cost, amortization of unrecognized net actuarial loss	14	23
Total non-service cost (benefit)	(20)	(12)
Net periodic benefit cost	10	21
Pension Plans [Member] | Claims and claim adjustment expenses [Member]
Defined benefit plan disclosure
Service cost	12	13
Total non-service cost (benefit)	(8)	(5)
Pension Plans [Member] | General and administrative expenses [Member]
Defined benefit plan disclosure
Service cost	18	20
Total non-service cost (benefit)	(12)	(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

Leases (Details)

Leases (Details) $ in Millions	3 Months Ended
	Mar. 31, 2019USD ($)
Leases [Abstract]
Operating leases	$ 22
Short-term leases	4
Lease expense	26
Net lease cost	26
Cash payments included in the measurement of lease liabilities reported in operating cash flows	24
Right-of-use assets obtained in exchange for new lease liabilities	$ 8
Weighted average discount rate (percent)	3.07%
Weighted average remaining lease term (in years)	5 years 2 months 12 days

Leases (Details) - Contractual

Leases (Details) - Contractual Maturities of Lease Liabilities $ in Millions	Mar. 31, 2019USD ($)
Leases [Abstract]
Lease payments due, remainder of 2019	$ 73
Lease payments due, 2020	95
Lease payments due, 2021	82
Lease payments due, 2022	61
Lease payments due, 2023	41
Lease payments due, thereafter	62
Total undiscounted lease payments	414
Less: present value adjustment	30
Operating lease liability	$ 384

Contingencies, Commitments an_2

Contingencies, Commitments and Guarantees (Details) - Commitments - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018
Contingencies, Commitments and Guarantees [Abstract]
Unfunded commitments to private equity limited partnerships and real estate partnerships	$ 1,560	$ 1,600

Contingencies, Commitments an_3

Contingencies, Commitments and Guarantees (Details) - Guarantees	Mar. 31, 2019USD ($)
Indemnifications related to the sale of businesses [Member]
Guarantor obligations
Maximum amount of contingent obligation	$ 358,000,000
Guarantees of certain investments and third-party loans [Member]
Guarantor obligations
Maximum amount of contingent obligation	0
Guarantees of certain insurance policy obligations [Member]
Guarantor obligations
Maximum amount of contingent obligation	480,000,000
Amount indemnified by a third party	$ 480,000,000

Consolidating Financial State_3

Consolidating Financial Statements (Unaudited) (Details) $ in Millions	Mar. 31, 2019USD ($)
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 fully and unconditionally guaranteed by The Travelers Companies, Inc.	$ 700

Consolidating Financial State_4

Consolidating Financial Statements (Details) - Consolidating Statement of Income (Unaudited) - USD ($)		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Consolidating Statement of Income
Premiums		$ 6,855,000,000	$ 6,537,000,000
Net investment income		582,000,000	603,000,000
Fee income		109,000,000	103,000,000
Net realized investment gains (losses)	[1]	53,000,000	(11,000,000)
Other revenues		72,000,000	54,000,000
Total revenues		7,671,000,000	7,286,000,000
Claims and claim adjustment expenses		4,442,000,000	4,296,000,000
Amortization of deferred acquisition costs		1,117,000,000	1,061,000,000
General and administrative expenses		1,057,000,000	1,062,000,000
Interest expense		88,000,000	89,000,000
Total claims and expenses		6,704,000,000	6,508,000,000
Income before income taxes		967,000,000	778,000,000
Income tax expense (benefit)		171,000,000	109,000,000
Net income		796,000,000	669,000,000
Total other-than-temporary impairment gains (losses)		(1,000,000)	0
Other-than-temporary impairment losses recognized in net realized investment gains (losses)		(1,000,000)	0
Other-than-temporary impairment losses recognized in other comprehensive income (loss)		0
Other-than-temporary impairment gains recognized in other comprehensive income (loss)			0
Reportable Legal Entities [Member] | TPC [Member]
Consolidating Statement of Income
Premiums		4,689,000,000	4,468,000,000
Net investment income		416,000,000	412,000,000
Fee income		109,000,000	103,000,000
Net realized investment gains (losses)		22,000,000	2,000,000
Other revenues		38,000,000	27,000,000
Total revenues		5,274,000,000	5,012,000,000
Claims and claim adjustment expenses		3,024,000,000	2,910,000,000
Amortization of deferred acquisition costs		745,000,000	705,000,000
General and administrative expenses		722,000,000	729,000,000
Interest expense		12,000,000	11,000,000
Total claims and expenses		4,503,000,000	4,355,000,000
Income before income taxes		771,000,000	657,000,000
Income tax expense (benefit)		146,000,000	106,000,000
Net income		625,000,000	551,000,000
Total other-than-temporary impairment gains (losses)		(1,000,000)
Other-than-temporary impairment losses recognized in net realized investment gains (losses)		(1,000,000)
Reportable Legal Entities [Member] | Other Subsidiaries [Member]
Consolidating Statement of Income
Premiums		2,166,000,000	2,069,000,000
Net investment income		155,000,000	185,000,000
Net realized investment gains (losses)		15,000,000	(12,000,000)
Other revenues		34,000,000	28,000,000
Total revenues		2,370,000,000	2,270,000,000
Claims and claim adjustment expenses		1,418,000,000	1,386,000,000
Amortization of deferred acquisition costs		372,000,000	356,000,000
General and administrative expenses		330,000,000	328,000,000
Total claims and expenses		2,120,000,000	2,070,000,000
Income before income taxes		250,000,000	200,000,000
Income tax expense (benefit)		42,000,000	32,000,000
Net income		208,000,000	168,000,000
Reportable Legal Entities [Member] | TRV [Member]
Consolidating Statement of Income
Net investment income		11,000,000	6,000,000
Net realized investment gains (losses)		16,000,000	(1,000,000)
Total revenues		27,000,000	5,000,000
General and administrative expenses		5,000,000	6,000,000
Interest expense		76,000,000	78,000,000
Total claims and expenses		81,000,000	84,000,000
Income before income taxes		(54,000,000)	(79,000,000)
Income tax expense (benefit)		(17,000,000)	(29,000,000)
Net income of subsidiaries		833,000,000	719,000,000
Net income		796,000,000	669,000,000
Eliminations [Member]
Consolidating Statement of Income
Other revenues			(1,000,000)
Total revenues			(1,000,000)
General and administrative expenses			(1,000,000)
Total claims and expenses			(1,000,000)
Net income of subsidiaries		(833,000,000)	(719,000,000)
Net income		$ (833,000,000)	$ (719,000,000)
[1]	Total other-than-temporary impairment (OTTI) gains (losses) were $(1) million and $0 for the three months ended March 31, 2019 and 2018, respectively. Of total OTTI, credit losses of $(1) million and $0 for the three months ended March 31, 2019 and 2018, respectively, were recognized in net realized investment gains (losses). In addition, unrealized gains (losses) from other changes in total OTTI of $0 for each of the three months ended March 31, 2019 and 2018, respectively, were recognized in other comprehensive income (loss) as part of changes in net unrealized gains (losses) on investment securities having credit losses recognized in the consolidated statement of income.

Consolidating Financial State_5

Consolidating Financial Statements (Details) - Consolidating Statement of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Consolidating Statement of Comprehensive Income
Net income	$ 796	$ 669
Changes in net unrealized gains (losses) on investment securities having no credit losses recognized in the consolidated statement of income	1,416	(1,203)
Changes in net unrealized gains (losses) on investment securities having credit losses recognized in the consolidated statement of income	5	(2)
Net changes in benefit plan assets and obligations	12	22
Net changes in unrealized foreign currency translation	50	6
Other comprehensive income (loss) before income taxes	1,483	(1,177)
Income tax expense (benefit)	306	(244)
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	1,177	(933)
Other comprehensive income (loss), net of taxes	1,177	(933)
Comprehensive income (loss)	1,973	(264)
Reportable Legal Entities [Member] | TPC [Member]
Consolidating Statement of Comprehensive Income
Net income	625	551
Changes in net unrealized gains (losses) on investment securities having no credit losses recognized in the consolidated statement of income	979	(838)
Changes in net unrealized gains (losses) on investment securities having credit losses recognized in the consolidated statement of income	4	(1)
Net changes in unrealized foreign currency translation	19	(25)
Other comprehensive income (loss) before income taxes	1,002	(864)
Income tax expense (benefit)	208	(175)
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	794	(689)
Other comprehensive income (loss), net of taxes	794	(689)
Comprehensive income (loss)	1,419	(138)
Reportable Legal Entities [Member] | Other Subsidiaries [Member]
Consolidating Statement of Comprehensive Income
Net income	208	168
Changes in net unrealized gains (losses) on investment securities having no credit losses recognized in the consolidated statement of income	435	(364)
Changes in net unrealized gains (losses) on investment securities having credit losses recognized in the consolidated statement of income	1	(1)
Net changes in unrealized foreign currency translation	31	31
Other comprehensive income (loss) before income taxes	467	(334)
Income tax expense (benefit)	93	(77)
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	374	(257)
Other comprehensive income (loss), net of taxes	374	(257)
Comprehensive income (loss)	582	(89)
Reportable Legal Entities [Member] | TRV [Member]
Consolidating Statement of Comprehensive Income
Net income	796	669
Changes in net unrealized gains (losses) on investment securities having no credit losses recognized in the consolidated statement of income	2	(1)
Net changes in benefit plan assets and obligations	12	22
Other comprehensive income (loss) before income taxes	14	21
Income tax expense (benefit)	5	8
Other comprehensive income (loss), net of taxes, before other comprehensive income (loss) of subsidiaries	9	13
Other comprehensive income (loss) of subsidiaries	1,168	(946)
Other comprehensive income (loss), net of taxes	1,177	(933)
Comprehensive income (loss)	1,973	(264)
Eliminations [Member]
Consolidating Statement of Comprehensive Income
Net income	(833)	(719)
Other comprehensive income (loss) of subsidiaries	(1,168)	946
Other comprehensive income (loss), net of taxes	(1,168)	946
Comprehensive income (loss)	$ (2,001)	$ 227

Consolidating Financial State_6

Consolidating Financial Statements (Details) - Consolidating Balance Sheet (Unaudited) - USD ($) $ in Millions	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Dec. 31, 2017
Consolidating Balance Sheet
Fixed maturities, at fair value	$ 65,500	$ 63,464
Equity securities, at fair value	400	368
Real estate investments	969	904
Short-term securities	4,094	3,985
Other investments	3,554	3,557
Total investments	74,517	72,278
Cash	357	373	$ 397	$ 344
Investment income accrued	591	624
Premiums receivable	7,947	7,506
Reinsurance recoverables	8,281	8,370
Ceded unearned premiums	935	578
Deferred acquisition costs	2,190	2,120
Deferred taxes	115	445
Contractholder receivables	4,811	4,785
Goodwill	3,949	3,937
Other intangible assets	341	345
Other assets	3,212	2,872
Total assets	107,246	104,233
Claims and claim adjustment expense reserves	50,718	50,668
Unearned premium reserves	14,122	13,555
Contractholder payables	4,811	4,785
Payables for reinsurance premiums	635	289
Debt	7,057	6,564
Other liabilities	5,563	5,478
Total liabilities	82,906	81,339
Common stock	23,243	23,144
Retained earnings	35,795	35,204
Accumulated other comprehensive income (loss)	(682)	(1,859)
Treasury stock, at cost	(34,016)	(33,595)
Total shareholders’ equity	24,340	22,894	22,979
Total liabilities and shareholders’ equity	107,246	104,233
Fixed maturities, available for sale, amortized cost	64,216	63,601
Equity securities, cost	$ 375	$ 382
Common stock, shares authorized (in shares)	1,750,000,000	1,750,000,000
Common stock, shares issued (in shares)	262,000,000	263,700,000
Common stock, shares outstanding (in shares)	261,900,000	263,600,000
Treasury stock, at cost (in shares)	514,200,000	510,900,000
Reportable Legal Entities [Member] | TPC [Member]
Consolidating Balance Sheet
Fixed maturities, at fair value	$ 45,336	$ 43,683
Equity securities, at fair value	105	105
Real estate investments	1	2
Short-term securities	1,645	1,855
Other investments	2,772	2,746
Total investments	49,859	48,391
Cash	150	181	175	157
Investment income accrued	406	434
Premiums receivable	5,356	5,089
Reinsurance recoverables	6,496	5,904
Ceded unearned premiums	838	522
Deferred acquisition costs	1,987	1,930
Deferred taxes	(76)	167
Contractholder receivables	4,801	3,867
Goodwill	2,581	2,578
Other intangible assets	222	224
Other assets	2,470	2,220
Total assets	75,090	71,507
Claims and claim adjustment expense reserves	34,800	34,093
Unearned premium reserves	9,872	9,414
Contractholder payables	4,801	3,867
Payables for reinsurance premiums	380	169
Debt	693	693
Other liabilities	4,287	4,133
Total liabilities	54,833	52,369
Additional paid-in capital	11,634	11,634
Retained earnings	8,390	8,065
Accumulated other comprehensive income (loss)	233	(561)
Total shareholders’ equity	20,257	19,138
Total liabilities and shareholders’ equity	75,090	71,507
Reportable Legal Entities [Member] | Other Subsidiaries [Member]
Consolidating Balance Sheet
Fixed maturities, at fair value	20,079	19,697
Equity securities, at fair value	106	92
Real estate investments	968	902
Short-term securities	581	759
Other investments	781	810
Total investments	22,515	22,260
Cash	207	192	221	$ 187
Investment income accrued	182	187
Premiums receivable	2,591	2,417
Reinsurance recoverables	1,785	2,466
Ceded unearned premiums	97	56
Deferred acquisition costs	203	190
Deferred taxes	222	302
Contractholder receivables	10	918
Goodwill	1,377	1,368
Other intangible assets	119	121
Other assets	393	15
Total assets	29,701	30,492
Claims and claim adjustment expense reserves	15,918	16,575
Unearned premium reserves	4,250	4,141
Contractholder payables	10	918
Payables for reinsurance premiums	255	120
Debt		32
Other liabilities	1,049	849
Total liabilities	21,482	22,635
Common stock	401	401
Additional paid-in capital	7,083	7,023
Retained earnings	807	879
Accumulated other comprehensive income (loss)	(72)	(446)
Total shareholders’ equity	8,219	7,857
Total liabilities and shareholders’ equity	29,701	30,492
Reportable Legal Entities [Member] | TRV [Member]
Consolidating Balance Sheet
Fixed maturities, at fair value	85	84
Equity securities, at fair value	189	171
Short-term securities	1,868	1,371
Other investments	1	1
Total investments	2,143	1,627
Cash			$ 1
Investment income accrued	3	3
Deferred taxes	(31)	(24)
Investment in subsidiaries	28,475	26,993
Other assets	349	669
Total assets	30,939	29,268
Debt	6,364	5,871
Other liabilities	227	496
Total liabilities	6,591	6,367
Common stock	23,243	23,144
Retained earnings	35,803	35,211
Accumulated other comprehensive income (loss)	(682)	(1,859)
Treasury stock, at cost	(34,016)	(33,595)
Total shareholders’ equity	24,348	22,901
Total liabilities and shareholders’ equity	30,939	29,268
Eliminations [Member]
Consolidating Balance Sheet
Goodwill	(9)	(9)
Investment in subsidiaries	(28,475)	(26,993)
Other assets		(32)
Total assets	(28,484)	(27,034)
Debt		(32)
Total liabilities		(32)
Common stock	(401)	(401)
Additional paid-in capital	(18,717)	(18,657)
Retained earnings	(9,205)	(8,951)
Accumulated other comprehensive income (loss)	(161)	1,007
Total shareholders’ equity	(28,484)	(27,002)
Total liabilities and shareholders’ equity	$ (28,484)	$ (27,034)

Consolidating Financial State_7

Consolidating Financial Statements (Details) - Consolidating Statement of Cash Flows (Unaudited) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Consolidating Statement of Cash Flows
Net income	$ 796	$ 669
Net adjustments to reconcile net income to net cash provided by operating activities	(157)	(115)
Net cash provided by operating activities	639	554
Proceeds from maturities of fixed maturities	1,556	1,950
Proceeds from sales of investments:
Fixed maturities	769	1,085
Equity securities	39	26
Other investments	105	114
Purchases of investments:
Fixed maturities	(2,914)	(3,920)
Equity securities	(22)	(20)
Real estate investments	(77)	(33)
Other investments	(146)	(142)
Net sales (purchases) of short-term securities	(109)	410
Securities transactions in course of settlement	295	202
Other investing activities	(82)	(53)
Net cash used in investing activities	(586)	(381)
Treasury stock acquired — share repurchase authorization	(375)	(350)
Treasury stock acquired — net employee share-based compensation	(46)	(51)
Dividends paid to shareholders	(205)	(197)
Payment of debt		(100)
Issuance of debt	492	491
Issuance of common stock — employee share options	63	85
Net cash used in financing activities	(71)	(122)
Effect of exchange rate changes on cash	2	2
Net increase (decrease) in cash	(16)	53
Cash at beginning of year	373	344
Cash at end of period	357	397
Income taxes paid	5	56
Interest paid	50	39
Reportable Legal Entities [Member] | TPC [Member]
Consolidating Statement of Cash Flows
Net income	625	551
Net adjustments to reconcile net income to net cash provided by operating activities	(110)	(126)
Net cash provided by operating activities	515	425
Proceeds from maturities of fixed maturities	1,043	1,453
Proceeds from sales of investments:
Fixed maturities	551	729
Equity securities	19	8
Other investments	90	76
Purchases of investments:
Fixed maturities	(2,228)	(2,836)
Equity securities	(1)	(1)
Other investments	(134)	(115)
Net sales (purchases) of short-term securities	210	729
Securities transactions in course of settlement	283	147
Other investing activities	(80)	(52)
Net cash used in investing activities	(247)	138
Dividends paid to parent company	(300)	(544)
Net cash used in financing activities	(300)	(544)
Effect of exchange rate changes on cash	1	(1)
Net increase (decrease) in cash	(31)	18
Cash at beginning of year	181	157
Cash at end of period	150	175
Income taxes paid	4	13
Interest paid	16	16
Reportable Legal Entities [Member] | Other Subsidiaries [Member]
Consolidating Statement of Cash Flows
Net income	208	168
Net adjustments to reconcile net income to net cash provided by operating activities	(42)	(57)
Net cash provided by operating activities	166	111
Proceeds from maturities of fixed maturities	508	493
Proceeds from sales of investments:
Fixed maturities	218	356
Equity securities	20	18
Other investments	15	38
Purchases of investments:
Fixed maturities	(682)	(1,078)
Equity securities	(20)	(18)
Real estate investments	(77)	(33)
Other investments	(12)	(27)
Net sales (purchases) of short-term securities	178	201
Securities transactions in course of settlement	13	56
Other investing activities	(2)	(1)
Net cash used in investing activities	159	5
Payment of debt	(32)
Dividends paid to parent company	(279)	(85)
Net cash used in financing activities	(311)	(85)
Effect of exchange rate changes on cash	1	3
Net increase (decrease) in cash	15	34
Cash at beginning of year	192	187
Cash at end of period	207	221
Income taxes paid	1	43
Reportable Legal Entities [Member] | TRV [Member]
Consolidating Statement of Cash Flows
Net income	796	669
Net adjustments to reconcile net income to net cash provided by operating activities	(227)	(22)
Net cash provided by operating activities	569	647
Proceeds from maturities of fixed maturities	5	4
Purchases of investments:
Fixed maturities	(4)	(6)
Equity securities	(1)	(1)
Net sales (purchases) of short-term securities	(497)	(520)
Securities transactions in course of settlement	(1)	(1)
Net cash used in investing activities	(498)	(524)
Treasury stock acquired — share repurchase authorization	(375)	(350)
Treasury stock acquired — net employee share-based compensation	(46)	(51)
Dividends paid to shareholders	(205)	(197)
Payment of debt		(100)
Issuance of debt	492	491
Issuance of common stock — employee share options	63	85
Net cash used in financing activities	(71)	(122)
Net increase (decrease) in cash		1
Cash at end of period		1
Interest paid	34	23
Eliminations [Member]
Consolidating Statement of Cash Flows
Net income	(833)	(719)
Net adjustments to reconcile net income to net cash provided by operating activities	222	90
Net cash provided by operating activities	(611)	(629)
Purchases of investments:
Payment of debt	32
Dividends paid to parent company	579	629
Net cash used in financing activities	$ 611	$ 629