CNA Financial (CNA) 10-Q 28 Oct 19 2019 Q3 Quarterly report Financial data

Cover Page Cover Page

Cover Page Cover Page - shares	9 Months Ended
	Sep. 30, 2019	Oct. 24, 2019
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Document Transition Report	false
Entity File Number	1-5823
Entity Registrant Name	CNA FINANCIAL CORPORATION
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	36-6169860
Entity Address, Address Line One	151 N. Franklin
Entity Address, City or Town	Chicago,
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60606
City Area Code	312
Local Phone Number	822-5000
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		271,478,277
Entity Central Index Key	0000021175
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3
Amendment Flag	false
New York Stock Exchange
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, Par value $2.50
Trading Symbol	"CNA"
Security Exchange Name	NYSE
Chicago Stock Exchange
Entity Information [Line Items]
Title of 12(b) Security	Common Stock, Par value $2.50
Trading Symbol	"CNA"
Security Exchange Name	CHX

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues
Net earned premiums	$ 1,890	$ 1,853	$ 5,517	$ 5,453
Net investment income	487	487	1,573	1,483
Net investment gains:
Other-than-temporary impairment losses	(14)	(3)	(34)	(9)
Other net investment gains	21	17	54	34
Net investment gains	7	14	20	25
Non-insurance warranty revenue	292	258	858	744
Other revenues	9	10	22	26
Total revenues	2,685	2,622	7,990	7,731
Claims, Benefits and Expenses
Insurance claims and policyholders’ benefits	1,614	1,312	4,323	3,978
Amortization of deferred acquisition costs	345	337	1,025	992
Non-insurance warranty expense	278	235	801	676
Other operating expenses	289	302	853	903
Interest	32	34	100	104
Total claims, benefits and expenses	2,558	2,220	7,102	6,653
Income before income tax	127	402	888	1,078
Income tax expense	(20)	(66)	(161)	(181)
Net income	$ 107	$ 336	$ 727	$ 897
Basic earnings per share
Basic earnings per share (in usd per share)	$ 0.39	$ 1.24	$ 2.68	$ 3.30
Diluted earnings per share
Diluted earnings per share (in usd per share)	$ 0.39	$ 1.23	$ 2.67	$ 3.29
Weighted Average Outstanding Common Stock and Common Stock Equivalents
Basic (in shares)	271.6	271.6	271.6	271.5
Diluted (in shares)	272.6	272.5	272.5	272.4

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income Unaudited) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Net income	$ 107	$ 336	$ 727	$ 897
Other Comprehensive Income (Loss), Net of Tax
Net unrealized gains on investments	41	(159)	1,007	(757)
Foreign currency translation adjustment	(29)	0	(12)	(40)
Pension and postretirement benefits	7	7	22	24
Other comprehensive income (loss), net of tax	19	(152)	1,017	(773)
Total comprehensive income	126	184	1,744	124
Net unrealized gains on investments with other-than-temporary impairments
Other Comprehensive Income (Loss), Net of Tax
Net unrealized gains on investments	0	(1)	4	(11)
Net unrealized gains on other investments
Other Comprehensive Income (Loss), Net of Tax
Net unrealized gains on investments	$ 41	$ (158)	$ 1,003	$ (746)

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Investments:
Fixed maturity securities at fair value (amortized cost of $38,258 and $38,085)	$ 42,459	$ 39,546
Equity securities at fair value (cost of $812 and $844)	841	780
Limited partnership investments	1,758	1,982
Other invested assets	60	53
Mortgage loans	923	839
Short term investments	1,494	1,286
Total investments	47,535	44,486
Cash	340	310
Reinsurance receivables (less allowance for uncollectible receivables of $29 and $29)	4,063	4,426
Insurance receivables (less allowance for uncollectible receivables of $40 and $42)	2,464	2,323
Accrued investment income	409	391
Deferred acquisition costs	668	633
Deferred income taxes	190	392
Property and equipment at cost (less accumulated depreciation of $201 and $216)	293	324
Goodwill	145	146
Deferred non-insurance warranty acquisition expense	2,772	2,513
Other assets (includes $- and $8 due from Loews Corporation)	1,571	1,208
Total assets	60,450	57,152
Insurance reserves:
Claim and claim adjustment expenses	21,596	21,984
Unearned premiums	4,608	4,183
Future policy benefits	12,305	10,597
Long term debt	2,678	2,680
Deferred non-insurance warranty revenue	3,707	3,402
Other liabilities (includes $47 and $23 due to Loews Corporation)	3,433	3,089
Total liabilities	48,327	45,935
Commitments and contingencies (Notes C and F)
Stockholders' Equity
Common stock ($2.50 par value; 500,000,000 shares authorized; 273,040,243 shares issued; 271,478,277 and 271,456,978 shares outstanding)	683	683
Additional paid-in capital	2,197	2,192
Retained earnings	9,171	9,277
Accumulated other comprehensive income (loss)	139	(878)
Treasury stock (1,561,966 and 1,583,265 shares), at cost	(67)	(57)
Total stockholders’ equity	12,123	11,217
Total liabilities and stockholders' equity	$ 60,450	$ 57,152

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets - (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Statement of Financial Position [Abstract]
Fixed maturities securities at amortized cost	$ 38,258	$ 38,085
Equity securities at cost	812	844
Allowance for uncollectible reinsurance	29	29
Allowance for uncollectible insurance receivables	40	42
Accumulated depreciation on property and equipment	201	216
Due to related parties	47	23
Due from related parties	$ 0	$ 8
Common stock, par value (in usd per share)	$ 2.50	$ 2.50
Common stock, shares authorized (in shares)	500,000,000	500,000,000
Common stock, shares issued (in shares)	273,040,243	273,040,243
Common stock, shares outstanding (in shares)	271,478,277	271,456,978
Treasury stock, shares (in shares)	1,561,966	1,583,265

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash Flows from Operating Activities
Net income	$ 727	$ 897
Adjustments to reconcile net income to net cash flows provided by operating activities:
Deferred income tax (benefit) expense	(72)	37
Trading portfolio activity	(1)	2
Net investment gains	(20)	(25)
Equity method investees	48	136
Net amortization of investments	(64)	(48)
Depreciation and amortization	52	59
Changes in:
Receivables, net	207	(47)
Accrued investment income	(18)	5
Deferred acquisition costs	(37)	(24)
Insurance reserves	337	108
Other, net	(179)	(232)
Net cash flows provided by operating activities	980	868
Dispositions:
Fixed maturity securities - sales	4,872	6,622
Fixed maturity securities - maturities, calls and redemptions	2,116	1,838
Equity securities	171	69
Limited partnerships	417	304
Mortgage loans	109	83
Purchases:
Fixed maturity securities	(7,053)	(8,244)
Equity securities	(140)	(177)
Limited partnerships	(167)	(380)
Mortgage loans	(193)	(112)
Change in other investments	(8)	(10)
Change in short term investments	(180)	158
Purchases of property and equipment	(20)	(87)
Other, net	16	16
Net cash flows (used) provided by investing activities	(60)	80
Cash Flows from Financing Activities
Dividends paid to common stockholders	(834)	(801)
Proceeds from the issuance of debt	496	0
Repayment of debt	(520)	(180)
Purchase of treasury stock	(18)	0
Other, net	(11)	(8)
Net cash flows used by financing activities	(887)	(989)
Effect of foreign exchange rate changes on cash	(3)	(4)
Net change in cash	30	(45)
Cash, beginning of year	310	355
Cash, end of period	$ 340	$ 310

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($)	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Total stockholder's equity at beginning of period at Dec. 31, 2017		$ 683,000,000	$ 2,175,000,000	$ 9,364,000,000	$ 16,000,000	$ (60,000,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation			11,000,000			2,000,000
Dividends to common stockholders ($0.35, $0.35, $3.05 and $2.95 per share)				(805,000,000)
Net income	$ 897,000,000			897,000,000
Other comprehensive income (loss)	(773,000,000)				(773,000,000)
Purchase of treasury stock						0
Total stockholder's equity at end of period at Sep. 30, 2018	11,510,000,000	683,000,000	2,186,000,000	9,456,000,000	(757,000,000)	(58,000,000)
Total stockholder's equity at beginning of period at Dec. 31, 2017		683,000,000	2,175,000,000	9,364,000,000	16,000,000	(60,000,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Purchase of treasury stock	0
Total stockholder's equity at end of period at Dec. 31, 2018	11,217,000,000	683,000,000	2,192,000,000	9,277,000,000	(878,000,000)	(57,000,000)
Total stockholder's equity at beginning of period at Jun. 30, 2018		683,000,000	2,179,000,000	9,216,000,000	(605,000,000)	(58,000,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation			7,000,000			0
Dividends to common stockholders ($0.35, $0.35, $3.05 and $2.95 per share)				(96,000,000)
Net income	336,000,000			336,000,000
Other comprehensive income (loss)	(152,000,000)				(152,000,000)
Purchase of treasury stock						0
Total stockholder's equity at end of period at Sep. 30, 2018	11,510,000,000	683,000,000	2,186,000,000	9,456,000,000	(757,000,000)	(58,000,000)
Total stockholder's equity at beginning of period at Dec. 31, 2018	11,217,000,000	683,000,000	2,192,000,000	9,277,000,000	(878,000,000)	(57,000,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation			5,000,000			8,000,000
Dividends to common stockholders ($0.35, $0.35, $3.05 and $2.95 per share)				(833,000,000)
Net income	727,000,000			727,000,000
Other comprehensive income (loss)	1,017,000,000				1,017,000,000
Purchase of treasury stock	(18,000,000)					(18,000,000)
Total stockholder's equity at end of period at Sep. 30, 2019	12,123,000,000	683,000,000	2,197,000,000	9,171,000,000	139,000,000	(67,000,000)
Total stockholder's equity at beginning of period at Jun. 30, 2019		683,000,000	2,190,000,000	9,159,000,000	120,000,000	(65,000,000)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation			7,000,000			0
Dividends to common stockholders ($0.35, $0.35, $3.05 and $2.95 per share)				(95,000,000)
Net income	107,000,000			107,000,000
Other comprehensive income (loss)	19,000,000				19,000,000
Purchase of treasury stock						(2,000,000)
Total stockholder's equity at end of period at Sep. 30, 2019	$ 12,123,000,000	$ 683,000,000	$ 2,197,000,000	$ 9,171,000,000	$ 139,000,000	$ (67,000,000)

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - (Parenthetical) - $ / shares	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement of Stockholders' Equity [Abstract]
Dividends declared per share (usd per share)	$ 0.35	$ 0.35	$ 3.05	$ 2.95

General

General	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
General	General Basis of Presentation The Condensed Consolidated Financial Statements include the accounts of CNA Financial Corporation (CNAF) and its subsidiaries. Collectively, CNAF and its subsidiaries are referred to as CNA or the Company. Loews Corporation (Loews) owned approximately 89% of the outstanding common stock of CNAF as of September 30, 2019 . The accompanying Condensed Consolidated Financial Statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP). Intercompany amounts have been eliminated. Certain financial information that is normally included in annual financial statements prepared in accordance with GAAP, including certain financial statement notes, is not required for interim reporting purposes and has been condensed or omitted. These statements should be read in conjunction with the Consolidated Financial Statements and notes thereto included in CNAF's Annual Report on Form 10-K filed with the Securities and Exchange Commission for the year ended December 31, 2018 , including the summary of significant accounting policies in Note A . The preparation of Condensed Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the Condensed Consolidated Financial Statements and the reported amounts of revenues and expenses during the reporting period. Actual results may differ from those estimates. The interim financial data as of September 30, 2019 and for the three and nine months ended September 30, 2019 and 2018 is unaudited. However, in the opinion of management, the interim data includes all adjustments, including normal recurring adjustments, necessary for a fair statement of the Company's results for the interim periods. The results of operations for the interim periods are not necessarily indicative of the results to be expected for the full year. Recently Adopted Accounting Standards Updates (ASU) ASU 2016-02: In February 2016, the Financial Accounting Standards Board (FASB) issued ASU No. 2016-02, Leases (Topic 842): Accounting for Leases. The updated accounting guidance requires lessees to recognize on the balance sheet assets and liabilities for the rights and obligations created by the majority of leases, including those historically accounted for as operating leases. On January 1, 2019, the Company adopted the updated guidance using a modified retrospective method. Prior period amounts have not been adjusted and continue to be reported in accordance with the previous accounting guidance. The Company utilized the package of practical expedients allowing the Company to not reassess whether a contract is or contains a lease, lease classification and initial direct costs. The Company also utilized the practical expedient to not separate lease and non-lease components for all leases. Adoption of the updated guidance resulted in the following changes to the Condensed Consolidated Balance Sheet on January 1, 2019: (In millions) Balance as of December 31, 2018 Adjustments Due to Adoption of Topic 842 Balance as of January 1, 2019 Property and equipment at cost (less accumulated depreciation) $ 324 $ 2 $ 326 Other assets 1,208 237 1,445 Other liabilities 3,089 239 3,328 As of January 1, 2019 , operating lease right-of-use (ROU) assets, included within Other assets, were reduced by accrued rent and lease incentives of $75 million previously classified as Other liabilities. The updated guidance did not impact the Condensed Consolidated Statements of Operations. See Note K to the Condensed Consolidated Financial Statements for additional information regarding leases. Accounting Standards Pending Adoption In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments . The updated accounting guidance requires changes to the recognition of credit losses on financial instruments not accounted for at fair value through net income. The guidance is effective for interim and annual periods beginning after December 15, 2019. The guidance will be applied using a modified retrospective approach with the cumulative effect recognized as an adjustment to retained earnings. A prospective transition approach is required for debt securities that have recognized an other-than-temporary impairment prior to the effective date. The Company is currently evaluating the effect the guidance will have on the Company's financial statements, but does not expect the impact to be material. The primary changes will be the use of the expected credit loss model for mortgage loans, reinsurance and insurance receivables and other financing receivables and the use of the allowance method rather than the write-down method for credit losses within the available-for-sale fixed maturities portfolio. The expected credit loss model will require a financial asset to be presented at the net amount expected to be collected. The allowance method for available-for-sale debt securities will allow the Company to record reversals of credit losses if the estimate of credit losses declines. The Company is currently in the process of evaluating existing impairment methodology, developing models to comply with the new guidance and accumulating all of the necessary internal and external information required to measure credit losses under the expected credit loss model. The Company is implementing changes to the information systems to assist with the accounting, including the recording of the allowance. The Company is also evaluating additional changes to processes to meet the reporting and disclosure requirements of the new guidance. In August 2018, the FASB issued ASU 2018-12, Financial Services-Insurance (Topic 944): Targeted Improvements to the Accounting for Long-Duration Contracts . The updated accounting guidance requires changes to the measurement and disclosure of long-duration contracts. The guidance requires entities to annually update cash flow assumptions, including morbidity and persistency, and update discount rate assumptions quarterly using an upper-medium grade fixed-income instrument yield. The effect of changes in cash flow assumptions will be recorded in Net income and the effect of changes in discount rate assumptions will be recorded in Other comprehensive income. This guidance is effective for interim and annual periods beginning after December 15, 2020; however the FASB has approved a one year deferral of the effective date. The guidance requires restatement of prior periods presented. Early adoption is permitted. The Company is currently evaluating the method and timing of adoption and the effect the updated guidance will have on its financial statements. The annual updating of cash flow assumptions is expected to increase income statement volatility. The quarterly change in discount rate is expected to increase volatility in the Company’s stockholders' equity, but that will be somewhat mitigated because Shadow Adjustments are eliminated under the new guidance. While the requirements of the new guidance represent a material change from existing GAAP, the underlying economics of the business and related cash flows are unchanged.

Earnings (Loss) Per Share

Earnings (Loss) Per Share	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Earnings (Loss) Per Share	Earnings (Loss) Per Share Earnings (loss) per share is based on the weighted average number of outstanding common shares. Basic earnings (loss) per share excludes the impact of dilutive securities and is computed by dividing Net income (loss) by the weighted average number of common shares outstanding for the period. Diluted earnings (loss) per share reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock. For the three and nine months ended September 30, 2019 , approximately 1 million and 920 thousand potential shares attributable to exercises or conversions into common stock under stock-based employee compensation plans were included in the calculation of diluted earnings per share. For those same periods, less than 1 thousand and approximately 3 thousand potential shares attributable to exercises or conversions into common stock under stock-based employee compensation plans were not included in the calculation of diluted earnings per share, because the effect would have been antidilutive. For the three and nine months ended September 30, 2018 , approximately 900 thousand and 925 thousand potential shares attributable to exercises or conversions into common stock under stock-based employee compensation plans were included in the calculation of diluted earnings per share. For those same periods, approximately 1 thousand and 3 thousand potential shares attributable to exercises or conversions into common stock under stock-based employee compensation plans were not included in the calculation of diluted earnings per share, because the effect would have been antidilutive. The Company repurchased 415,695 shares of CNAF common stock at an aggregate cost of $ 18 million during the nine months ended September 30, 2019 . No repurchases were made during 2018 .

Investments

Investments	9 Months Ended
	Sep. 30, 2019
Investments [Abstract]
Investments	Investments The significant components of Net investment income are presented in the following table. Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Fixed maturity securities $ 452 $ 449 $ 1,362 $ 1,339 Equity securities 16 10 62 32 Limited partnership investments 12 23 125 93 Mortgage loans 13 11 37 36 Short term investments 8 6 27 18 Trading portfolio 2 1 6 6 Other — 1 2 4 Gross investment income 503 501 1,621 1,528 Investment expense (16 ) (14 ) (48 ) (45 ) Net investment income $ 487 $ 487 $ 1,573 $ 1,483 During the three and nine months ended September 30, 2019 , $5 million and $26 million of Net investment income was recognized due to the change in fair value of common stock still held as of September 30, 2019 . During the three and nine months ended September 30, 2018 , Net investment income was reduced by $2 million due to the change in fair value of common stock still held as of September 30, 2018 . Net investment gains (losses) are presented in the following table. Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Net investment gains (losses): Fixed maturity securities: Gross gains $ 34 $ 42 $ 98 $ 148 Gross losses (31 ) (32 ) (104 ) (116 ) Net investment gains (losses) on fixed maturity securities 3 10 (6 ) 32 Equity securities 7 2 60 (23 ) Derivatives (2 ) 1 (13 ) 10 Short term investments and other (1 ) 1 (21 ) 6 Net investment gains (losses) $ 7 $ 14 $ 20 $ 25 During the three and nine months ended September 30, 2019 , $7 million and $60 million of Net investment gains were recognized due to the change in fair value of non-redeemable preferred stock still held as of September 30, 2019 . During the three and nine months ended September 30, 2018 , $2 million of Net investment gains and $23 million of Net investment losses were recognized due to the change in fair value of non-redeemable preferred stock still held as of September 30, 2018 . Net investment gains (losses) for the nine months ended September 30, 2019 included a $21 million loss related to the second quarter 2019 redemption of the Company's $500 million senior notes due August 2020. The components of Other-than-temporary impairment (OTTI) losses recognized in earnings by asset type are presented in the following table. Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Fixed maturity securities available-for-sale: Corporate and other bonds $ 12 $ 1 $ 24 $ 6 Asset-backed 2 2 10 3 OTTI losses recognized in earnings $ 14 $ 3 $ 34 $ 9 The following tables present a summary of fixed maturity securities. September 30, 2019 Cost or Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Unrealized OTTI Losses (Gains) (In millions) Fixed maturity securities available-for-sale: Corporate and other bonds $ 19,806 $ 2,263 $ 42 $ 22,027 $ — States, municipalities and political subdivisions 9,154 1,641 — 10,795 — Asset-backed: Residential mortgage-backed 4,718 157 1 4,874 (23 ) Commercial mortgage-backed 2,066 117 3 2,180 1 Other asset-backed 1,884 46 4 1,926 (3 ) Total asset-backed 8,668 320 8 8,980 (25 ) U.S. Treasury and obligations of government-sponsored enterprises 124 7 — 131 — Foreign government 491 20 — 511 — Redeemable preferred stock 10 — — 10 — Total fixed maturity securities available-for-sale 38,253 4,251 50 42,454 $ (25 ) Total fixed maturity securities trading 5 — — 5 Total fixed maturity securities $ 38,258 $ 4,251 $ 50 $ 42,459 December 31, 2018 Cost or Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Unrealized OTTI Losses (Gains) (In millions) Fixed maturity securities available-for-sale: Corporate and other bonds $ 18,764 $ 791 $ 395 $ 19,160 $ — States, municipalities and political subdivisions 9,681 1,076 9 10,748 — Asset-backed: Residential mortgage-backed 4,815 68 57 4,826 (20 ) Commercial mortgage-backed 2,200 28 32 2,196 — Other asset-backed 1,975 11 24 1,962 — Total asset-backed 8,990 107 113 8,984 (20 ) U.S. Treasury and obligations of government-sponsored enterprises 156 3 — 159 — Foreign government 480 5 4 481 — Redeemable preferred stock 10 — — 10 — Total fixed maturity securities available-for-sale 38,081 1,982 521 39,542 $ (20 ) Total fixed maturity securities trading 4 — — 4 Total fixed maturity securities $ 38,085 $ 1,982 $ 521 $ 39,546 The net unrealized gains on investments included in the tables above are recorded as a component of Accumulated other comprehensive income (AOCI). When presented in AOCI, these amounts are net of tax and any required Shadow Adjustments. To the extent that unrealized gains on fixed income securities supporting certain products within the Life & Group segment would result in a premium deficiency if realized, a related increase in Insurance reserves is recorded, net of tax, as a reduction of net unrealized gains through Other comprehensive income (loss) (Shadow Adjustments). As of September 30, 2019 and December 31, 2018 , the net unrealized gains on investments included in AOCI were correspondingly reduced by Shadow Adjustments of $2,237 million and $1,078 million The following tables present the estimated fair value and gross unrealized losses of fixed maturity securities in a gross unrealized loss position by the length of time in which the securities have continuously been in that position. Less than 12 Months 12 Months or Longer Total September 30, 2019 Estimated Gross Estimated Gross Estimated Gross Unrealized Losses (In millions) Fixed maturity securities available-for-sale: Corporate and other bonds $ 890 $ 26 $ 200 $ 16 $ 1,090 $ 42 States, municipalities and political subdivisions 20 — 2 — 22 — Asset-backed: Residential mortgage-backed 150 — 38 1 188 1 Commercial mortgage-backed 83 2 26 1 109 3 Other asset-backed 416 3 6 1 422 4 Total asset-backed 649 5 70 3 719 8 U.S. Treasury and obligations of government-sponsored enterprises 14 — 4 — 18 — Foreign government 17 — 2 — 19 — Total $ 1,590 $ 31 $ 278 $ 19 $ 1,868 $ 50 Less than 12 Months 12 Months or Longer Total December 31, 2018 Estimated Gross Estimated Gross Estimated Gross (In millions) Fixed maturity securities available-for-sale: Corporate and other bonds $ 8,543 $ 340 $ 825 $ 55 $ 9,368 $ 395 States, municipalities and political subdivisions 517 8 5 1 522 9 Asset-backed: Residential mortgage-backed 1,932 23 1,119 34 3,051 57 Commercial mortgage-backed 728 10 397 22 1,125 32 Other asset-backed 834 21 125 3 959 24 Total asset-backed 3,494 54 1,641 59 5,135 113 U.S. Treasury and obligations of government-sponsored enterprises 21 — 19 — 40 — Foreign government 114 2 124 2 238 4 Total $ 12,689 $ 404 $ 2,614 $ 117 $ 15,303 $ 521 Based on current facts and circumstances, the Company believes the unrealized losses presented in the September 30, 2019 securities in a gross unrealized loss position table above are not indicative of the ultimate collectibility of the current amortized cost of the securities, but rather are attributable to changes in interest rates, credit spreads and other factors. The Company has no current intent to sell securities with unrealized losses, nor is it more likely than not that it will be required to sell prior to recovery of amortized cost; accordingly, the Company has determined that there are no additional OTTI losses to be recorded as of September 30, 2019 . The following table presents the activity related to the pretax credit loss component reflected in Retained earnings on fixed maturity securities still held as of September 30, 2019 and 2018 for which a portion of an OTTI loss was recognized in Other comprehensive income (loss). Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Beginning balance of credit losses on fixed maturity securities $ 16 $ 21 $ 18 $ 27 Reductions for securities sold during the period — (2 ) (2 ) (8 ) Ending balance of credit losses on fixed maturity securities $ 16 $ 19 $ 16 $ 19 Contractual Maturity The following table presents available-for-sale fixed maturity securities by contractual maturity. September 30, 2019 December 31, 2018 (In millions) Cost or Amortized Cost Estimated Fair Value Cost or Amortized Cost Estimated Fair Value Due in one year or less $ 1,071 $ 1,091 $ 1,350 $ 1,359 Due after one year through five years 10,992 11,470 7,979 8,139 Due after five years through ten years 13,694 14,711 16,859 16,870 Due after ten years 12,496 15,182 11,893 13,174 Total $ 38,253 $ 42,454 $ 38,081 $ 39,542 Actual maturities may differ from contractual maturities because certain securities may be called or prepaid. Securities not due at a single date are allocated based on weighted average life. Derivative Financial Instruments The Company holds an embedded derivative on a funds withheld liability with a notional value of $170 million and $172 million as of September 30, 2019 and December 31, 2018 and a fair value of $(9) million and $4 million as of September 30, 2019 and December 31, 2018 . The embedded derivative on the funds withheld liability is accounted for separately and reported with the funds withheld liability in Other liabilities on the Condensed Consolidated Balance Sheets. Investment Commitments As part of its overall investment strategy, the Company invests in various assets which require future purchase, sale or funding commitments. These investments are recorded once funded, and the related commitments may include future capital calls from various third-party limited partnerships, signed and accepted mortgage loan applications, and obligations related to privately placed debt securities. As of September 30, 2019 , the Company had commitments to purchase or fund approximately $865 million and sell approximately $90 million under the terms of these investments.

Fair Value

Fair Value	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value	Fair Value Fair value is the price that would be received upon sale of an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date. The following fair value hierarchy is used in selecting inputs, with the highest priority given to Level 1, as these are the most transparent or reliable. Level 1 - Quoted prices for identical instruments in active markets. Level 2 - Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations in which all significant inputs are observable in active markets. Level 3 - Valuations derived from valuation techniques in which one or more significant inputs are not observable. Prices may fall within Level 1, 2 or 3 depending upon the methodology and inputs used to estimate fair value for each specific security. In general, the Company seeks to price securities using third-party pricing services. Securities not priced by pricing services are submitted to independent brokers for valuation and, if those are not available, internally developed pricing models are used to value assets using a methodology and inputs the Company believes market participants would use to value the assets. Prices obtained from third-party pricing services or brokers are not adjusted by the Company. The Company performs control procedures over information obtained from pricing services and brokers to ensure prices received represent a reasonable estimate of fair value and to confirm representations regarding whether inputs are observable or unobservable. Procedures may include i) the review of pricing service methodologies or broker pricing qualifications, ii) back-testing, where past fair value estimates are compared to actual transactions executed in the market on similar dates, iii) exception reporting, where period-over-period changes in price are reviewed and challenged with the pricing service or broker based on exception criteria, iv) deep dives, where the Company performs an independent analysis of the inputs and assumptions used to price individual securities and v) pricing validation, where prices received are compared to prices independently estimated by the Company. Assets and Liabilities Measured at Fair Value Assets and liabilities measured at fair value on a recurring basis are presented in the following tables. Corporate bonds and other includes obligations of the U.S. Treasury, government-sponsored enterprises, foreign governments and redeemable preferred stock. September 30, 2019 Total Assets/Liabilities at Fair Value (In millions) Level 1 Level 2 Level 3 Assets Fixed maturity securities: Corporate bonds and other $ 161 $ 22,095 $ 428 $ 22,684 States, municipalities and political subdivisions — 10,795 — 10,795 Asset-backed — 8,784 196 8,980 Total fixed maturity securities 161 41,674 624 42,459 Equity securities: Common stock 114 — 6 120 Non-redeemable preferred stock 52 653 16 721 Total equity securities 166 653 22 841 Short term and other 288 1,089 — 1,377 Total assets $ 615 $ 43,416 $ 646 $ 44,677 Liabilities Other liabilities $ — $ 9 $ — $ 9 Total liabilities $ — $ 9 $ — $ 9 December 31, 2018 Total Assets/Liabilities at Fair Value (In millions) Level 1 Level 2 Level 3 Assets Fixed maturity securities: Corporate bonds and other $ 196 $ 19,396 $ 222 $ 19,814 States, municipalities and political subdivisions — 10,748 — 10,748 Asset-backed — 8,787 197 8,984 Total fixed maturity securities 196 38,931 419 39,546 Equity securities: Common stock 144 — 4 148 Non-redeemable preferred stock 48 570 14 632 Total equity securities 192 570 18 780 Short term and other 216 949 — 1,165 Total assets $ 604 $ 40,450 $ 437 $ 41,491 Liabilities Other liabilities $ — $ (4 ) $ — $ (4 ) Total liabilities $ — $ (4 ) $ — $ (4 ) The tables below present a reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3). Level 3 (In millions) Corporate bonds and other States, municipalities and political subdivisions Asset-backed Equity securities Total Balance as of July 1, 2019 $ 338 $ — $ 193 $ 22 $ 553 Total realized and unrealized investment gains (losses): Reported in Net investment gains (losses) — — — — — Reported in Other comprehensive income (loss) 14 — 1 — 15 Total realized and unrealized investment gains (losses) 14 — 1 — 15 Purchases 79 — 22 — 101 Sales — — — — — Settlements (3 ) — (4 ) — (7 ) Transfers into Level 3 — — — — — Transfers out of Level 3 — — (16 ) — (16 ) Balance as of September 30, 2019 $ 428 $ — $ 196 $ 22 $ 646 Unrealized gains (losses) on Level 3 assets and liabilities held as of September 30, 2019 recognized in Net income (loss) in the period $ — $ — $ — $ — $ — Unrealized gains (losses) on Level 3 assets and liabilities held as of September 30, 2019 recognized in Other comprehensive income (loss) in the period 14 — 2 — 16 Level 3 (In millions) Corporate bonds and other States, municipalities and political subdivisions Asset-backed Equity securities Total Balance as of July 1, 2018 $ 94 $ 1 $ 273 $ 17 $ 385 Total realized and unrealized investment gains (losses): Reported in Net investment gains (losses) — — (2 ) 1 (1 ) Reported in Other comprehensive income (loss) — — — — — Total realized and unrealized investment gains (losses) — — (2 ) 1 (1 ) Purchases 67 — 55 — 122 Sales — — — — — Settlements (3 ) (1 ) (25 ) — (29 ) Transfers into Level 3 30 — 29 — 59 Transfers out of Level 3 — — (32 ) — (32 ) Balance as of September 30, 2018 $ 188 $ — $ 298 $ 18 $ 504 Unrealized gains (losses) on Level 3 assets and liabilities held as of September 30, 2018 recognized in Net income (loss) in the period $ — $ — $ (2 ) $ 1 $ (1 ) Unrealized gains (losses) on Level 3 assets and liabilities held as of September 30, 2018 recognized in Other comprehensive income (loss) in the period — — 1 — 1 Level 3 (In millions) Corporate bonds and other States, municipalities and political subdivisions Asset-backed Equity securities Total Balance as of January 1, 2019 $ 222 $ — $ 197 $ 18 $ 437 Total realized and unrealized investment gains (losses): Reported in Net investment gains (losses) — — — 2 2 Reported in Other comprehensive income (loss) 34 — 8 — 42 Total realized and unrealized investment gains (losses) 34 — 8 2 44 Purchases 211 — 42 2 255 Sales — — — — — Settlements (7 ) — (12 ) — (19 ) Transfers into Level 3 — — 45 — 45 Transfers out of Level 3 (32 ) — (84 ) — (116 ) Balance as of September 30, 2019 $ 428 $ — $ 196 $ 22 $ 646 Unrealized gains (losses) on Level 3 assets and liabilities held as of September 30, 2019 recognized in Net income (loss) in the period $ — $ — $ — $ 2 $ 2 Unrealized gains (losses) on Level 3 assets and liabilities held as of September 30, 2019 recognized in Other comprehensive income (loss) in the period 29 — 9 — 38 Level 3 (In millions) Corporate bonds and other States, municipalities and political subdivisions Asset-backed Equity securities Total Balance as of January 1, 2018 $ 98 $ 1 $ 335 $ 20 $ 454 Total realized and unrealized investment gains (losses): Reported in Net investment gains (losses) (1 ) — 5 (2 ) 2 Reported in Other comprehensive income (loss) (1 ) — (6 ) — (7 ) Total realized and unrealized investment gains (losses) (2 ) — (1 ) (2 ) (5 ) Purchases 69 — 126 — 195 Sales (5 ) — (72 ) — (77 ) Settlements (7 ) (1 ) (37 ) — (45 ) Transfers into Level 3 35 — 42 — 77 Transfers out of Level 3 — — (95 ) — (95 ) Balance as of September 30, 2018 $ 188 $ — $ 298 $ 18 $ 504 Unrealized gains (losses) on Level 3 assets and liabilities held as of September 30, 2018 recognized in Net income (loss) in the period $ — $ — $ (2 ) $ (2 ) $ (4 ) Unrealized gains (losses) on Level 3 assets and liabilities held as of September 30, 2018 recognized in Other comprehensive income (loss) in the period (2 ) — (2 ) — (4 ) Securities may be transferred in or out of levels within the fair value hierarchy based on the availability of observable market information and quoted prices used to determine the fair value of the security. The availability of observable market information and quoted prices varies based on market conditions and trading volume. Valuation Methodologies and Inputs The following section describes the valuation methodologies and relevant inputs used to measure different financial instruments at fair value, including an indication of the level in the fair value hierarchy in which the instruments are generally classified. Fixed Maturity Securities Level 1 securities include highly liquid and exchange traded bonds, valued using quoted market prices. Level 2 securities include most other fixed maturity securities as the significant inputs are observable in the marketplace. All classes of Level 2 fixed maturity securities are valued using a methodology based on information generated by market transactions involving identical or comparable assets, a discounted cash flow methodology, or a combination of both when necessary. Common inputs for all classes of fixed maturity securities include prices from recently executed transactions of similar securities, marketplace quotes, benchmark yields, spreads off benchmark yields, interest rates and U.S. Treasury or swap curves. Specifically for asset-backed securities, key inputs include prepayment and default projections based on past performance of the underlying collateral and current market data. Fixed maturity securities are primarily assigned to Level 3 in cases where broker/dealer quotes are significant inputs to the valuation and there is a lack of transparency as to whether these quotes are based on information that is observable in the marketplace. Level 3 securities also include private placement debt securities whose fair value is determined using internal models with inputs that are not market observable. Equity Securities Level 1 equity securities include publicly traded securities valued using quoted market prices. Level 2 securities are primarily valued using pricing for similar securities, recently executed transactions and other pricing models utilizing market observable inputs. Level 3 securities are primarily priced using broker/dealer quotes and internal models with inputs that are not market observable. Short Term and Other Invested Assets Securities that are actively traded or have quoted prices are classified as Level 1. These securities include money market funds and treasury bills. Level 2 primarily includes commercial paper, for which all inputs are market observable. Fixed maturity securities purchased within one year of maturity are classified consistent with fixed maturity securities discussed above. Short term investments as presented in the tables above differ from the amounts presented on the Consolidated Balance Sheets because certain short term investments, such as time deposits, are not measured at fair value. As of September 30, 2019 and December 31, 2018 , there were approximately $55 million and $48 million of overseas deposits within other invested assets, which can be redeemed at net asset value in 90 days or less. Overseas deposits are excluded from the fair value hierarchy because their fair value is recorded using the net asset value per share (or equivalent) practical expedient. Derivative Financial Investments Level 2 investments primarily include the embedded derivative on the funds withheld liability. The embedded derivative on funds withheld liability is valued using the change in fair value of the assets supporting the funds withheld liability, which are fixed maturity securities valued with observable inputs. Significant Unobservable Inputs The following tables present quantitative information about the significant unobservable inputs utilized by the Company in the fair value measurements of Level 3 assets. Valuations for assets and liabilities not presented in the tables below are primarily based on broker/dealer quotes for which there is a lack of transparency as to inputs used to develop the valuations. The quantitative detail of these unobservable inputs is neither provided nor reasonably available to the Company. The weighted average rate is calculated based on fair value. September 30, 2019 Estimated Fair Value (In millions) Valuation Technique(s) Unobservable Input(s) Range (Weighted Average) Fixed maturity securities $ 496 Discounted cash flow Credit spread 1% - 6% (2%) December 31, 2018 Estimated Fair Value Valuation Technique(s) Unobservable Input(s) Range (Weighted Average) Fixed maturity securities $ 228 Discounted cash flow Credit spread 1% - 12% (3%) For fixed maturity securities, an increase to the credit spread assumptions would result in a lower fair value measurement. Financial Assets and Liabilities Not Measured at Fair Value The carrying amount and estimated fair value of the Company's financial assets and liabilities which are not measured at fair value on the Condensed Consolidated Balance Sheets are presented in the following tables. September 30, 2019 Carrying Amount Estimated Fair Value (In millions) Level 1 Level 2 Level 3 Total Assets Mortgage loans $ 923 $ — $ — $ 950 $ 950 Note receivable 21 — — 21 21 Liabilities Long term debt $ 2,678 $ — $ 2,905 $ — $ 2,905 December 31, 2018 Carrying Estimated Fair Value (In millions) Level 1 Level 2 Level 3 Total Assets Mortgage loans $ 839 $ — $ — $ 827 $ 827 Note receivable 35 — — 35 35 Liabilities Long term debt $ 2,680 $ — $ 2,731 $ — $ 2,731 The following methods and assumptions were used to estimate the fair value of these financial assets and liabilities. The fair value of mortgage loans was based on the present value of the expected future cash flows discounted at the current interest rate for origination of similar quality loans, adjusted for specific loan risk. The fair value of the note receivable was based on the present value of the expected future cash flows discounted at the current interest rate for origination of similar notes, adjusted for specific credit risk. The note receivable is included within Other assets on the Condensed Consolidated Balance Sheets. The Company's senior notes and debentures were valued based on observable market prices. The fair value for other debt was estimated using discounted cash flows based on current incremental borrowing rates for similar borrowing arrangements. The carrying amounts reported on the Condensed Consolidated Balance Sheets for Cash, Short term investments not carried at fair value, Accrued investment income and certain Other assets and Other liabilities approximate fair value due to the short term nature of these items. These assets and liabilities are not listed in the tables above.

Claim and Claim Adjustment Expe

Claim and Claim Adjustment Expense and Future Policy Benefit Reserves	9 Months Ended
	Sep. 30, 2019
Liability for Claims and Claims Adjustment Expense [Abstract]
Claim and Claim Adjustment Expense Reserves	Claim, Claim Adjustment Expense and Future Policy Benefit Reserves Property and casualty insurance claim and claim adjustment expense reserves represent the estimated amounts necessary to resolve all outstanding claims, including incurred but not reported (IBNR) claims as of the reporting date. The Company's reserve projections are based primarily on detailed analysis of the facts in each case, the Company's experience with similar cases and various historical development patterns. Consideration is given to historical patterns such as claim reserving trends and settlement practices, loss payments, pending levels of unpaid claims and product mix, as well as court decisions and economic conditions, including inflation, and public attitudes. All of these factors can affect the estimation of claim and claim adjustment expense reserves. Establishing claim and claim adjustment expense reserves, including claim and claim adjustment expense reserves for catastrophic events that have occurred, is an estimation process. Many factors can ultimately affect the final settlement of a claim and, therefore, the necessary reserve. Changes in the law, results of litigation, medical costs, the cost of repair materials and labor rates can affect ultimate claim costs. In addition, time can be a critical part of reserving determinations since the longer the span between the incidence of a loss and the payment or settlement of the claim, the more variable the ultimate settlement amount can be. Accordingly, short-tail claims, such as property damage claims, tend to be more reasonably estimable than long-tail claims, such as workers' compensation, general liability and professional liability claims. Adjustments to prior year reserve estimates, if necessary, are reflected in the results of operations in the period that the need for such adjustments is determined. There can be no assurance that the Company's ultimate cost for insurance losses will not exceed current estimates. Catastrophes are an inherent risk of the property and casualty insurance business and have contributed to material period-to-period fluctuations in our results of operations and/or equity. The Company reported catastrophe losses, net of reinsurance, of $32 million and $128 million for the three and nine months ended September 30, 2019 . The Company reported catastrophe losses, net of reinsurance, of $46 million and $106 million for the three and nine months ended September 30, 2018 . Net catastrophe losses in 2019 and 2018 related primarily to U.S. weather related events. Liability for Unpaid Claim and Claim Adjustment Expenses The following table presents a reconciliation between beginning and ending claim and claim adjustment expense reserves, including claim and claim adjustment expense reserves of the Life & Group segment. For the nine months ended September 30 (In millions) 2019 2018 Reserves, beginning of year: Gross $ 21,984 $ 22,004 Ceded 4,019 3,934 Net reserves, beginning of year 17,965 18,070 Net incurred claim and claim adjustment expenses: Provision for insured events of current year 3,968 3,866 Increase (decrease) in provision for insured events of prior years (65 ) (173 ) Amortization of discount 143 136 Total net incurred (1) 4,046 3,829 Net payments attributable to: Current year events (599 ) (658 ) Prior year events (3,547 ) (3,415 ) Total net payments (4,146 ) (4,073 ) Foreign currency translation adjustment and other 29 (80 ) Net reserves, end of period 17,894 17,746 Ceded reserves, end of period 3,702 3,858 Gross reserves, end of period $ 21,596 $ 21,604 (1) Total net incurred above does not agree to Insurance claims and policyholders' benefits as reflected on the Condensed Consolidated Statements of Operations due to amounts related to retroactive reinsurance deferred gain accounting, uncollectible reinsurance and loss deductible receivables, and benefit expenses related to future policy benefits, which are not reflected in the table above. Net Prior Year Development Changes in estimates of claim and claim adjustment expense reserves, net of reinsurance, for prior years are defined as net prior year loss reserve development (development). These changes can be favorable or unfavorable. The following table presents development recorded for the Specialty, Commercial, International and Corporate & Other segments. Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Pretax (favorable) unfavorable development: Specialty $ (20 ) $ (53 ) $ (58 ) $ (127 ) Commercial 35 (5 ) 15 (27 ) International 1 (2 ) 14 (4 ) Corporate & Other — (2 ) — (2 ) Total pretax (favorable) unfavorable development $ 16 $ (62 ) $ (29 ) $ (160 ) Specialty The following table presents further detail of the development recorded for the Specialty segment. Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Pretax (favorable) unfavorable development: Medical Professional Liability $ 29 $ 15 $ 59 $ 38 Other Professional Liability and Management Liability (18 ) (45 ) (37 ) (113 ) Surety (43 ) (20 ) (83 ) (50 ) Warranty — (1 ) (7 ) (7 ) Other 12 (2 ) 10 5 Total pretax (favorable) unfavorable development $ (20 ) $ (53 ) $ (58 ) $ (127 ) Three Months 2019 Unfavorable development in medical professional liability was primarily due to higher than expected indemnity severity in accident years 2016 through 2018 in our aging services business. Favorable development in other professional liability and management liability was due to lower than expected large claim losses in recent accident years in our public company directors and officers liability (D&O) business. Favorable development in surety was due to lower than expected frequency for accident years 2015 through 2018. Unfavorable development in other was primarily due to higher than expected severity in aging services related to auto liability coverages. 2018 Unfavorable development in medical professional liability was primarily driven by higher than expected frequency and severity in aging services in accident years 2014 through 2017. Favorable development in other professional liability and management liability was primarily driven by favorable outcomes on individual claims in accident years 2013 and prior in financial institutions. Favorable development in surety was due to continued lower than expected loss emergence for accident years 2017 and prior. Nine Months 2019 Unfavorable development in medical professional liability was primarily due to higher than expected indemnity severity in accident years 2016 through 2018 in our aging services business, higher than expected severity in accident year 2013 in our allied healthcare business, unfavorable outcomes on individual claims and higher than expected severity in accident year 2017 in our dentists business. Favorable development in other professional liability and management liability was primarily due to lower than expected claim frequency and favorable outcomes on individual claims in accident years 2017 and prior related to financial institutions and lower than expected large claim losses in recent accident years in our public company D&O business. Favorable development in surety was due to lower than expected frequency for accident years 2018 and prior. Unfavorable development in other was primarily due to higher than expected severity in aging services related to auto liability coverages. 2018 Unfavorable development in medical professional liability was primarily due to higher than expected severity in accident years 2014 and 2017 in our hospitals business and higher than expected frequency and severity in aging services in accident years 2014 through 2017. Favorable development in other professional liability and management liability was primarily due to lower than expected claim frequency for accident years 2013 through 2017 related to financial institutions and professional liability errors and omissions (E&O), favorable severity for accident years 2012 and prior related to professional liability E&O, and favorable outcomes on individual claims in financial institutions in accident years 2013 and prior. Favorable development in surety was due to lower than expected loss emergence for accident years 2017 and prior. Commercial The following table presents further detail of the development recorded for the Commercial segment. Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Pretax (favorable) unfavorable development: Commercial Auto $ (16 ) $ 1 $ (24 ) $ — General Liability 43 (5 ) 36 13 Workers' Compensation 7 (2 ) 2 (14 ) Property and Other 1 1 1 (26 ) Total pretax (favorable) unfavorable development $ 35 $ (5 ) $ 15 $ (27 ) Three Months 2019 Favorable development in commercial auto was primarily due to a decline in bodily injury frequency in accident year 2018 and continued lower than expected severity across accident years 2013 through 2016. Unfavorable development in general liability was primarily due to higher than expected emergence in mass tort related to accident years 2009 and prior, 2015 and 2016. Nine Months 2019 Favorable development in commercial auto was primarily due to a decline in bodily injury frequency in accident year 2018 and continued lower than expected severity across accident years 2016 and prior. Unfavorable development in general liability was primarily due to higher than expected emergence in mass tort as well as higher than expected large loss experience in our excess and umbrella business in accident year 2017. 2018 Unfavorable development in general liability was driven by higher than expected claim severity in umbrella in accident years 2013 through 2015. International The following table presents further detail of the development recorded for the International segment. Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Pretax (favorable) unfavorable development: Casualty $ (6 ) $ (5 ) $ (11 ) $ (11 ) Property 3 2 14 14 Energy and Marine 1 (5 ) 9 (10 ) Specialty (1) 3 6 2 3 Total pretax (favorable) unfavorable development $ 1 $ (2 ) $ 14 $ (4 ) (1) Effective January 1, 2019 the Healthcare and Technology line of business has been absorbed within the Specialty line of business in the International segment. Prior period information has been conformed to the new line of business presentation. Nine Months 2019 Favorable development in casualty was driven by lower than expected large losses and claim severity in accident years 2014 and prior in Hardy and Europe. Unfavorable development in property was driven by higher than expected claims in Hardy on 2018 accident year catastrophes. 2018 Favorable development in casualty was primarily driven by better than expected frequency in the liability portion of the package business in Canada and general liability in Europe. Unfavorable development in property was primarily driven by higher than expected severity in Canada and higher than expected frequency in Hardy, both in accident year 2017. Favorable development in energy and marine was primarily driven by better than expected large loss frequency in the energy book in recent accident years. Unfavorable development in specialty was driven by increased severity in accident year 2017 related to professional indemnity, partially offset by favorable development in healthcare in Europe primarily driven by lower than expected frequency in accident years 2015 and prior. Asbestos and Environmental Pollution (A&EP) Reserves In 2010, Continental Casualty Company (CCC) together with several of the Company’s insurance subsidiaries completed a transaction with National Indemnity Company (NICO), a subsidiary of Berkshire Hathaway Inc., under which substantially all of the Company’s legacy A&EP liabilities were ceded to NICO through a Loss Portfolio Transfer (LPT). At the effective date of the transaction, the Company ceded approximately $1.6 billion of net A&EP claim and allocated claim adjustment expense reserves to NICO under a retroactive reinsurance agreement with an aggregate limit of $4 billion . The $ 1.6 billion of claim and allocated claim adjustment expense reserves ceded to NICO was net of $1.2 billion of ceded claim and allocated claim adjustment expense reserves under existing third-party reinsurance contracts. The NICO LPT aggregate reinsurance limit also covers credit risk on the existing third-party reinsurance related to these liabilities. The Company paid NICO a reinsurance premium of $2 billion and transferred to NICO billed third-party reinsurance receivables related to A&EP claims with a net book value of $215 million , resulting in total consideration of $2.2 billion . In years subsequent to the effective date of the LPT, the Company recognized adverse prior year development on its A&EP reserves resulting in additional amounts ceded under the LPT. As a result, the cumulative amounts ceded under the LPT have exceeded the $2.2 billion consideration paid, resulting in the NICO LPT moving into a gain position, requiring retroactive reinsurance accounting. Under retroactive reinsurance accounting, this gain is deferred and only recognized in earnings in proportion to actual paid recoveries under the LPT. Over the life of the contract, there is no economic impact as long as any additional losses incurred are within the limit of the LPT. In a period in which the Company recognizes a change in the estimate of A&EP reserves that increases or decreases the amounts ceded under the LPT, the proportion of actual paid recoveries to total ceded losses is affected and the change in the deferred gain is recognized in earnings as if the revised estimate of ceded losses was available at the effective date of the LPT. The effect of the deferred retroactive reinsurance benefit is recorded in Insurance claims and policyholders' benefits on the Condensed Consolidated Statements of Operations. The following table presents the impact of the Loss Portfolio Transfer on the Condensed Consolidated Statements of Operations. Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Additional amounts ceded under LPT: Net A&EP adverse development before consideration of LPT $ — $ — $ — $ 113 Provision for uncollectible third-party reinsurance on A&EP — — — (16 ) Total additional amounts ceded under LPT — — — 97 Retroactive reinsurance benefit recognized (7 ) (12 ) (43 ) (84 ) Pretax impact of deferred retroactive reinsurance $ (7 ) $ (12 ) $ (43 ) $ 13 The Company intends to complete its annual A&EP reserve review in the fourth quarter of 2019 and maintain this timing for all future annual A&EP reserve reviews. The Company completed A&EP reserve reviews in both the first and fourth quarters of 2018 . Based upon the Company's 2018 first quarter A&EP reserve review, net unfavorable prior year development of $113 million was recognized before consideration of cessions to the LPT for the nine months ended September 30, 2018 . The 2018 unfavorable development was driven by higher than anticipated defense costs on direct asbestos and environmental accounts and paid losses on assumed reinsurance exposures. Additionally, in 2018, the Company released a portion of its provision for uncollectible third-party reinsurance. As of September 30, 2019 and December 31, 2018 , the cumulative amounts ceded under the LPT were $3.1 billion . The unrecognized deferred retroactive reinsurance benefit was $331 million and $374 million as of September 30, 2019 and December 31, 2018 and is included within Other liabilities on the Condensed Consolidated Balance Sheets. NICO established a collateral trust account as security for its obligations to the Company. The fair value of the collateral trust account was $3.3 billion and $2.7 billion as of September 30, 2019 and December 31, 2018 . In addition, Berkshire Hathaway Inc. guaranteed the payment obligations of NICO up to the aggregate reinsurance limit as well as certain of NICO’s performance obligations under the trust agreement. NICO is responsible for claims handling and billing and collection from third-party reinsurers related to the majority of the Company’s A&EP claims. Life & Group Policyholder Reserves The Company’s Life & Group segment includes its run-off long term care business as well as structured settlement obligations not funded by annuities related to certain property and casualty claimants. Long term care policies provide benefits for nursing homes, assisted living facilities and home health care subject to various daily and lifetime caps. Generally, policyholders must continue to make periodic premium payments to keep the policy in force and the Company has the ability to increase policy premiums, subject to state regulatory approval. The Company maintains both claim and claim adjustment expense reserves as well as future policy benefit reserves for policyholder benefits for the Life & Group segment. Claim and claim adjustment expense reserves consist of estimated reserves for long term care policyholders that are currently receiving benefits, including claims that have been incurred but are not yet reported. In developing the claim and claim adjustment expense reserve estimates for long term care policies, the Company’s actuaries perform a detailed claim experience study on an annual basis. The study reviews the sufficiency of existing reserves for policyholders currently on claim and includes an evaluation of expected benefit utilization and claim duration. The Company’s recorded claim and claim adjustment expense reserves reflect management's best estimate after incorporating the results of the most recent study. In addition, claim and claim adjustment expense reserves are also maintained for the structured settlement obligations. The Company's most recent annual long term care claim experience study was completed in the third quarter of 2019 and resulted in a $56 million pretax reduction in claim and claim adjustment expense reserves primarily due to lower claim severity than anticipated in the reserve estimates. The Company's 2018 annual long term care claim experience study was completed in the third quarter of 2018 and resulted in a $31 million pretax reduction in claim and claim adjustment expense reserves. Future policy benefit reserves represent the active life reserves related to the Company’s long term care policies which are the present value of expected future benefit payments and expenses less expected future premium. The determination of these reserves is fundamental to the Company’s financial results and requires management to make estimates and assumptions about expected investment and policyholder experience over the life of the contract. Since many of these contracts may be in force for several decades, these assumptions are subject to significant estimation risk. The actuarial assumptions that management believes are subject to the most variability are morbidity, persistency, discount rate and anticipated future premium rate increases. Morbidity is the frequency and severity of injury, illness, sickness and diseases contracted. Persistency is the percentage of policies remaining in force and can be affected by policy lapses, benefit reductions and death. Discount rate is influenced by the investment yield on assets supporting long term care reserves which is subject to interest rate and market volatility and may also be affected by changes to the Internal Revenue Code. As future premium rate increases are generally subject to regulatory approval, the exact timing and size of the approved rate increases are unknown. As a result of this variability, the Company’s long term care reserves may be subject to material increases if actual experience develops adversely to the Company’s expectations. Annually, management assesses the adequacy of its long term care future policy benefit reserves by performing a gross premium valuation (GPV) to determine if there is a premium deficiency. Management also uses the GPV process to evaluate the adequacy of its claim and claim adjustment expense reserves for structured settlement obligations. Under the GPV, management estimates required reserves using best estimate assumptions as of the date of the assessment without provisions for adverse deviation. The GPV required reserves are then compared to the existing recorded reserves. If the GPV required reserves are greater than the existing recorded reserves, the existing assumptions are unlocked and future policy benefit reserves are increased to the greater amount. Any such increase is reflected in the Company’s results of operations in the period in which the need for such adjustment is determined. Periodically, management engages independent third parties to assess the appropriateness of its best estimate assumptions. The most recent third party assessment, performed earlier this year, validated the assumption setting process and confirmed the best estimate assumptions appropriately reflected the experience data at that time. In the third quarter of 2019 the Company performed the GPV for the long term care future policy benefit reserves. This GPV indicated a premium deficiency primarily driven by lower discount rate assumptions. Recognition of the premium deficiency resulted in a $216 million pretax increase in policyholders' benefits reflected in the Company's results of operations.

Legal Proceedings, Contingencie

Legal Proceedings, Contingencies and Guarantees	9 Months Ended
	Sep. 30, 2019
Legal Proceedings, Commitments and Contingencies, and Guarantees [Abstract]
Legal Proceedings, Contingencies and Guarantees	Legal Proceedings, Contingencies and Guarantees The Company is a party to various claims and routine litigation incidental to its business, which, based on the facts and circumstances currently known, are not material to the Company's results of operations or financial position. Guarantees As of September 30, 2019 and December 31, 2018 , the Company had recorded liabilities of approximately $5 million related to guarantee and indemnification agreements and management does not believe that any future indemnity claims will be significantly greater than the amounts recorded. In the course of selling business entities and assets to third parties, the Company indemnified purchasers for certain losses, some of which are not limited by a contractual monetary amount. As of September 30, 2019 , the Company had outstanding unlimited indemnifications that included tax liabilities arising prior to a purchaser's ownership of an entity or asset, defects in title at the time of sale, employee claims arising prior to closing and in some cases losses arising from certain litigation and undisclosed liabilities. Certain provisions of the indemnification agreements survive indefinitely, while others survive until the applicable statutes of limitation expire, or until the agreed-upon contract terms expire. The Company also provided guarantees, if the primary obligor fails to perform, to holders of structured settlement annuities provided by a previously owned subsidiary. As of September 30, 2019 , the potential amount of future payments the Company could be required to pay under these guarantees was approximately $1.7 billion , which will be paid over the lifetime of the annuitants. The Company does not believe any payment is likely under these guarantees, as the Company is the beneficiary of a trust that must be maintained at a level that approximates the discounted reserves for these annuities.

Benefit Plans

Benefit Plans	9 Months Ended
	Sep. 30, 2019
Retirement Benefits [Abstract]
Benefit Plans	Benefit Plans The components of net periodic pension cost (benefit) are presented in the following table. Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Net periodic pension cost (benefit) Service cost $ — $ — $ — $ — Non-service cost (benefit): Interest cost on projected benefit obligation 25 23 75 70 Expected return on plan assets (36 ) (40 ) (107 ) (120 ) Amortization of net actuarial (gain) loss 10 10 30 28 Settlement loss — — — 5 Total non-service cost (benefit) (1 ) (7 ) (2 ) (17 ) Total net periodic pension cost (benefit) $ (1 ) $ (7 ) $ (2 ) $ (17 ) For the three and nine months ended September 30, 2019 , the Company recognized less than $1 million and $1 million of non-service benefit in Insurance claims and policyholders' benefits and less than $1 million and $1 million of non-service benefit in Other operating expenses. For the three and nine months ended September 30, 2018 , the Company recognized $3 million and $6 million of non-service benefit in Insurance claims and policyholders' benefits and $4 million and $11 million of non-service benefit in Other operating expenses.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss) by Component	9 Months Ended
	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated Other Comprehensive Income (Loss) by Component	Accumulated Other Comprehensive Income (Loss) by Component The tables below display the changes in Accumulated other comprehensive income (loss) by component. (In millions) Net unrealized gains (losses) on investments with OTTI losses Net unrealized gains (losses) on other investments Pension and postretirement benefits Cumulative foreign currency translation adjustment Total Balance as of July 1, 2019 $ 20 $ 1,023 $ (760 ) $ (163 ) $ 120 Other comprehensive income (loss) before reclassifications — 44 — (29 ) 15 Amounts reclassified from accumulated other comprehensive income (loss) net of tax (expense) benefit of $-, $-, $2, $- and $2 — 3 (7 ) — (4 ) Other comprehensive income (loss) net of tax (expense) benefit of $-, $(11), $(2), $- and $(13) — 41 7 (29 ) 19 Balance as of September 30, 2019 $ 20 $ 1,064 $ (753 ) $ (192 ) $ 139 (In millions) Net unrealized gains (losses) on investments with OTTI losses Net unrealized gains (losses) on other investments Pension and postretirement benefits Cumulative foreign currency translation adjustment Total Balance as of July 1, 2018 $ 20 $ 271 $ (758 ) $ (138 ) $ (605 ) Other comprehensive income (loss) before reclassifications (1 ) (148 ) — — (149 ) Amounts reclassified from accumulated other comprehensive income (loss) net of tax (expense) benefit of $-, $(2), $1, $- and $(1) — 10 (7 ) — 3 Other comprehensive income (loss) net of tax (expense) benefit of $-, $42, $(1), $- and $41 (1 ) (158 ) 7 — (152 ) Balance as of September 30, 2018 $ 19 $ 113 $ (751 ) $ (138 ) $ (757 ) (In millions) Net unrealized gains (losses) on investments with OTTI losses Net unrealized gains (losses) on other investments Pension and postretirement benefits Cumulative foreign currency translation adjustment Total Balance as of January 1, 2019 $ 16 $ 61 $ (775 ) $ (180 ) $ (878 ) Other comprehensive income (loss) before reclassifications 3 999 (1 ) (12 ) 989 Amounts reclassified from accumulated other comprehensive income (loss) net of tax (expense) benefit of $-, $1, $6, $- and $7 (1 ) (4 ) (23 ) — (28 ) Other comprehensive income (loss) net of tax (expense) benefit of $(2), $(266), $(6), $- and $(274) 4 1,003 22 (12 ) 1,017 Balance as of September 30, 2019 $ 20 $ 1,064 $ (753 ) $ (192 ) $ 139 (In millions) Net unrealized gains (losses) on investments with OTTI losses Net unrealized gains (losses) on other investments Pension and postretirement benefits Cumulative foreign currency translation adjustment Total Balance as of January 1, 2018 $ 30 $ 859 $ (775 ) $ (98 ) $ 16 Other comprehensive income (loss) before reclassifications (12 ) (718 ) — (40 ) (770 ) Amounts reclassified from accumulated other comprehensive income (loss) net of tax (expense) benefit of $-, $(7), $6, $- and $(1) (1 ) 28 (24 ) — 3 Other comprehensive income (loss) net of tax (expense) benefit of $3, $197, $(6), $- and $194 (11 ) (746 ) 24 (40 ) (773 ) Balance as of September 30, 2018 $ 19 $ 113 $ (751 ) $ (138 ) $ (757 ) Amounts reclassified from Accumulated other comprehensive income (loss) shown above are reported in Net income (loss) as follows: Component of AOCI Consolidated Statements of Operations Line Item Affected by Reclassifications Net unrealized gains (losses) on investments with OTTI losses Net investment gains (losses) Net unrealized gains (losses) on other investments Net investment gains (losses) Pension and postretirement benefits Other operating expenses and Insurance claims and policyholders' benefits

Business Segments

Business Segments	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Business Segments	Business Segments The Company's property and casualty commercial insurance operations are managed and reported in three business segments: Specialty, Commercial and International. These three segments are collectively referred to as Property & Casualty Operations. The Company's operations outside of Property & Casualty Operations are managed and reported in two segments: Life & Group and Corporate & Other. The accounting policies of the segments are the same as those described in Note A to the Consolidated Financial Statements within CNAF's Annual Report on Form 10-K for the year ended December 31, 2018 . The Company manages most of its assets on a legal entity basis, while segment operations are generally conducted across legal entities. As such, only Insurance and Reinsurance receivables, Insurance reserves, Deferred acquisition costs, Goodwill and Deferred non-insurance warranty acquisition expense and revenue are readily identifiable for individual segments. Distinct investment portfolios are not maintained for every individual segment; accordingly, allocation of assets to each segment is not performed. Therefore, a significant portion of Net investment income and Net investment gains or losses are allocated primarily based on each segment's net carried insurance reserves, as adjusted. All significant intersegment income and expense have been eliminated. Income taxes have been allocated on the basis of the taxable income of the segments. In the following tables, certain financial measures are presented to provide information used by management to monitor the Company's operating performance. Management utilizes these financial measures to monitor the Company's insurance operations and investment portfolio. The performance of the Company's insurance operations is monitored by management through core income (loss), which is derived from certain income statement amounts. The Company's investment portfolio is monitored by management through analysis of various factors including unrealized gains and losses on securities, portfolio duration and exposure to market and credit risk. Core income (loss) is calculated by excluding from net income (loss) the after-tax effects of i) net investment gains (losses), ii) income or loss from discontinued operations, iii) any cumulative effects of changes in accounting guidance and iv) deferred tax asset and liability remeasurement as a result of an enacted U.S. Federal tax rate change. The calculation of core income (loss) excludes net investment gains or losses because net investment gains or losses are generally driven by economic factors that are not necessarily consistent with key drivers of underwriting performance, and are therefore not considered an indication of trends in insurance operations. The Company's results of operations and selected balance sheet items by segment are presented in the following tables. Three months ended September 30, 2019 International Life & Corporate Eliminations Total (In millions) Operating revenues Net earned premiums $ 712 $ 813 $ 236 $ 130 $ — $ (1 ) $ 1,890 Net investment income 121 136 17 207 6 — 487 Non-insurance warranty revenue 292 — — — — — 292 Other revenues 1 10 (1 ) (1 ) 1 (1 ) 9 Total operating revenues 1,126 959 252 336 7 (2 ) 2,678 Claims, benefits and expenses Net incurred claims and benefits 411 564 163 476 (7 ) — 1,607 Policyholders’ dividends 2 5 — — — — 7 Amortization of deferred acquisition costs 155 134 56 — — — 345 Non-insurance warranty expense 278 — — — — — 278 Other insurance related expenses 71 123 35 29 — (1 ) 257 Other expenses 13 9 7 1 35 (1 ) 64 Total claims, benefits and expenses 930 835 261 506 28 (2 ) 2,558 Core income (loss) before income tax 196 124 (9 ) (170 ) (21 ) — 120 Income tax (expense) benefit on core income (loss) (43 ) (27 ) — 48 4 — (18 ) Core income (loss) $ 153 $ 97 $ (9 ) $ (122 ) $ (17 ) $ — 102 Net investment gains (losses) 7 Income tax (expense) benefit on net investment gains (losses) (2 ) Net investment gains (losses), after tax 5 Net income $ 107 Three months ended September 30, 2018 International Life & Corporate Eliminations Total (In millions) Operating revenues Net earned premiums $ 684 $ 782 $ 255 $ 133 $ — $ (1 ) $ 1,853 Net investment income 124 144 14 200 5 — 487 Non-insurance warranty revenue 258 — — — — — 258 Other revenues — 8 1 (1 ) 2 — 10 Total operating revenues 1,066 934 270 332 7 (1 ) 2,608 Claims, benefits and expenses Net incurred claims and benefits 373 496 172 277 (12 ) — 1,306 Policyholders’ dividends 1 5 — — — — 6 Amortization of deferred acquisition costs 153 127 57 — — — 337 Non-insurance warranty expense 235 — — — — — 235 Other insurance related expenses 68 133 36 31 (1 ) (1 ) 266 Other expenses 11 10 3 2 44 — 70 Total claims, benefits and expenses 841 771 268 310 31 (1 ) 2,220 Core income (loss) before income tax 225 163 2 22 (24 ) — 388 Income tax (expense) benefit on core income (loss) (48 ) (36 ) (1 ) 10 4 — (71 ) Core income (loss) $ 177 $ 127 $ 1 $ 32 $ (20 ) $ — 317 Net investment gains (losses) 14 Income tax (expense) benefit on net investment gains (losses) (1 ) Net investment gains (losses), after tax 13 Net deferred tax asset remeasurement 6 Net income $ 336 Nine months ended September 30, 2019 Specialty Commercial International Life & Group Corporate & Other Eliminations Total (In millions) Operating revenues Net earned premiums $ 2,061 $ 2,339 $ 729 $ 390 $ — $ (2 ) $ 5,517 Net investment income 410 480 47 616 20 — 1,573 Non-insurance warranty revenue 858 — — — — — 858 Other revenues 1 20 — — 5 (4 ) 22 Total operating revenues 3,330 2,839 776 1,006 25 (6 ) 7,970 Claims, benefits and expenses Net incurred claims and benefits 1,198 1,581 472 1,093 (40 ) — 4,304 Policyholders’ dividends 4 15 — — — — 19 Amortization of deferred acquisition costs 454 391 180 — — — 1,025 Non-insurance warranty expense 801 — — — — — 801 Other insurance related expenses 217 372 94 87 (2 ) (2 ) 766 Other expenses 37 27 14 5 108 (4 ) 187 Total claims, benefits and expenses 2,711 2,386 760 1,185 66 (6 ) 7,102 Core income (loss) before income tax 619 453 16 (179 ) (41 ) — 868 Income tax (expense) benefit on core income (loss) (136 ) (97 ) (2 ) 74 7 — (154 ) Core income (loss) $ 483 $ 356 $ 14 $ (105 ) $ (34 ) $ — 714 Net investment gains (losses) 20 Income tax (expense) benefit on net investment gains (losses) (7 ) Net investment gains (losses), after tax 13 Net income $ 727 September 30, 2019 (In millions) Reinsurance receivables $ 599 $ 759 $ 242 $ 394 $ 2,098 $ — $ 4,092 Insurance receivables 992 1,243 260 8 1 — 2,504 Deferred acquisition costs 314 264 90 — — — 668 Goodwill 117 — 28 — — — 145 Deferred non-insurance warranty acquisition expense 2,772 — — — — — 2,772 Insurance reserves Claim and claim adjustment expenses 5,285 8,610 1,802 3,707 2,192 — 21,596 Unearned premiums 2,329 1,679 475 126 — (1 ) 4,608 Future policy benefits — — — 12,305 — — 12,305 Deferred non-insurance warranty revenue 3,707 — — — — — 3,707 Nine months ended September 30, 2018 Specialty Commercial International Life & Group Corporate & Other Eliminations Total (In millions) Operating revenues Net earned premiums $ 2,039 $ 2,278 $ 739 $ 398 $ — $ (1 ) $ 5,453 Net investment income 376 450 43 598 16 — 1,483 Non-insurance warranty revenue 744 — — — — — 744 Other revenues 1 24 — — 2 (1 ) 26 Total operating revenues 3,160 2,752 782 996 18 (2 ) 7,706 Claims, benefits and expenses Net incurred claims and benefits 1,124 1,434 480 907 15 — 3,960 Policyholders’ dividends 3 15 — — — — 18 Amortization of deferred acquisition costs 447 375 170 — — — 992 Non-insurance warranty expense 676 — — — — — 676 Other insurance related expenses 202 386 102 91 (1 ) (1 ) 779 Other expenses 34 31 6 5 153 (1 ) 228 Total claims, benefits and expenses 2,486 2,241 758 1,003 167 (2 ) 6,653 Core income (loss) before income tax 674 511 24 (7 ) (149 ) — 1,053 Income tax (expense) benefit on core income (loss) (143 ) (108 ) (7 ) 43 30 — (185 ) Core income (loss) $ 531 $ 403 $ 17 $ 36 $ (119 ) $ — 868 Net investment gains (losses) 25 Income tax (expense) benefit on net investment gains (losses) (2 ) Net investment gains (losses), after tax 23 Net deferred tax asset remeasurement 6 Net income $ 897 December 31, 2018 (In millions) Reinsurance receivables $ 649 $ 795 $ 250 $ 414 $ 2,347 $ — $ 4,455 Insurance receivables 947 1,277 284 9 (152 ) — 2,365 Deferred acquisition costs 308 230 95 — — — 633 Goodwill 117 — 29 — — — 146 Deferred non-insurance warranty acquisition expense 2,513 — — — — — 2,513 Insurance reserves Claim and claim adjustment expenses 5,465 8,743 1,750 3,601 2,425 — 21,984 Unearned premiums 2,132 1,454 475 122 — — 4,183 Future policy benefits — — — 10,597 — — 10,597 Deferred non-insurance warranty revenue 3,402 — — — — — 3,402 The following table presents operating revenue by line of business for each reportable segment. Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Specialty Management & Professional Liability $ 638 $ 616 $ 1,903 $ 1,867 Surety 156 153 446 427 Warranty & Alternative Risks 332 297 981 866 Specialty revenues 1,126 1,066 3,330 3,160 Commercial Middle Market 560 530 1,652 1,555 Small Business 115 125 351 364 Other Commercial Insurance 284 279 836 833 Commercial revenues 959 934 2,839 2,752 International Canada 70 66 204 187 Europe 91 94 270 273 Hardy 91 110 302 322 International revenues 252 270 776 782 Life & Group revenues 336 332 1,006 996 Corporate & Other revenues 7 7 25 18 Eliminations (2 ) (1 ) (6 ) (2 ) Total operating revenues 2,678 2,608 7,970 7,706 Net investment gains (losses) 7 14 20 25 Total revenues $ 2,685 $ 2,622 $ 7,990 $ 7,731

Non-Insurance Revenues from Con

Non-Insurance Revenues from Contracts with Customers	9 Months Ended
	Sep. 30, 2019
Revenue from Contract with Customer [Abstract]
Non-Insurance Revenues from Contracts with Customers	Non-Insurance Revenues from Contracts with Customers The Company had deferred non-insurance warranty revenue balances of $3.7 billion and $3.4 billion reported in Deferred non-insurance warranty revenue as of September 30, 2019 and December 31, 2018 . For the three and nine months ended September 30, 2019 , the Company recognized $236 million and $ 747 million of revenues that were included in the deferred revenue balance as of January 1, 2019 . For the three and nine months ended September 30, 2018 , the Company recognized $200 million and $635 million of revenues that were included in the deferred revenue balance as of January 1, 2018. For the three and nine months ended September 30, 2019 and 2018 , Non-insurance warranty revenue recognized from performance obligations related to prior periods due to a change in estimate was not material. The Company expects to recognize approximately $278 million of the deferred revenue in the remainder of 2019, $1.0 billion in 2020, $0.8 billion in 2021 and $1.6 billion thereafter.

Leases

Leases	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Leases	Leases A lease provides the lessee the right to control the use of an identified asset for a period of time in exchange for consideration. Operating lease ROU assets and lease liabilities are included in Other assets and Other liabilities on the Company's Condensed Consolidated Balance Sheets. ROU assets represent the Company's right to use an underlying asset for the lease term and operating lease liabilities represent the Company's obligation to make lease payments arising from the lease. The Company determines if an arrangement is a lease at inception. Operating lease ROU assets and liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. Most operating leases contain renewal options that provide for rent increases based on prevailing market conditions. Certain leases contain options to terminate before maturity. The lease term used to calculate the ROU asset includes any renewal options or lease termination that the Company expects to exercise. The discount rate used to determine the commencement date present value of lease payments is the interest rate implicit in the lease, or when that is not readily determinable, the Company utilizes its secured borrowing rate. ROU assets include any lease payments required to be made prior to commencement and exclude lease incentives. Both ROU assets and lease liabilities exclude variable payments not based on an index or rate, which are treated as period costs. The Company's lease agreements do not contain significant residual value guarantees, restrictions or covenants. The Company occupies office facilities under lease agreements that expire at various dates. In addition, data processing, office and transportation equipment is leased under agreements that expire at various dates. The Company’s leases generally include lease and non-lease components, which the Company has elected to account for as a single lease component. Variable lease costs not based on an index or rate consist of non-lease components, which are being accounted for as lease components, and represent charges for services provided by the landlord and our reimbursement for the landlord’s costs, including real estate taxes and insurance. The Company does not have any significant finance leases. Operating lease cost was $9 million and $28 million for the three and nine months ended September 30, 2019 . Variable lease cost was $5 million and $13 million for the three and nine months ended September 30, 2019 . Cash paid for amounts included in operating lease liabilities was $8 million and $25 million for the three and nine months ended September 30, 2019 . Operating lease ROU assets obtained in exchange for lease obligations was $11 million for the nine months ended September 30, 2019. The following table presents operating lease ROU assets and lease liabilities. (In millions) September 30, 2019 Operating lease ROU assets $ 223 Operating lease liabilities 304 The following table presents the maturities of operating lease liabilities as of September 30, 2019 . (In millions) Operating Leases 2019 (Excluding the nine months ended September 30, 2019) $ 6 2020 39 2021 42 2022 39 2023 34 Thereafter 213 Total lease payments 373 Less: Discount (69 ) Total operating lease liabilities $ 304 The following table presents the weighted average remaining lease term for operating leases and weighted average discount rate used in calculating operating lease right-of-use assets. September 30, 2019 Weighted average remaining lease term 10.9 years Weighted average discount rate 3.4 % The following table presents the expected future minimum lease payments to be made under non-cancelable operating leases as of December 31, 2018 . (In millions) Future Minimum Lease Payments 2019 $ 35 2020 39 2021 41 2022 38 2023 32 Thereafter 200 Total $ 385

General (Policies)

General (Policies)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Consolidation	Basis of Presentation The Condensed Consolidated Financial Statements include the accounts of CNA Financial Corporation (CNAF) and its subsidiaries. Collectively, CNAF and its subsidiaries are referred to as CNA or the Company. Loews Corporation (Loews) owned approximately 89% of the outstanding common stock of CNAF as of September 30, 2019 . The accompanying Condensed Consolidated Financial Statements have been prepared in conformity with accounting principles generally accepted in the United States of America (GAAP). Intercompany amounts have been eliminated. Certain financial information that is normally included in annual financial statements prepared in accordance with GAAP, including certain financial statement notes, is not required for interim reporting purposes and has been condensed or omitted. These statements should be read in conjunction with the Consolidated Financial Statements and notes thereto included in CNAF's Annual Report on Form 10-K filed with the Securities and Exchange Commission for the year ended December 31, 2018 , including the summary of significant accounting policies in Note A . The preparation of Condensed Consolidated Financial Statements in conformity with GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the Condensed Consolidated Financial Statements and the reported amounts of revenues and expenses during the reporting period. Actual results may differ from those estimates. The interim financial data as of September 30, 2019 and for the three and nine months ended September 30, 2019 and 2018 is unaudited. However, in the opinion of management, the interim data includes all adjustments, including normal recurring adjustments, necessary for a fair statement of the Company's results for the interim periods. The results of operations for the interim periods are not necessarily indicative of the results to be expected for the full year.
Recently Adopted Accounting Standards Updates and Accounting Standards Pending Adoption	Recently Adopted Accounting Standards Updates (ASU) ASU 2016-02: In February 2016, the Financial Accounting Standards Board (FASB) issued ASU No. 2016-02, Leases (Topic 842): Accounting for Leases. The updated accounting guidance requires lessees to recognize on the balance sheet assets and liabilities for the rights and obligations created by the majority of leases, including those historically accounted for as operating leases. On January 1, 2019, the Company adopted the updated guidance using a modified retrospective method. Prior period amounts have not been adjusted and continue to be reported in accordance with the previous accounting guidance. The Company utilized the package of practical expedients allowing the Company to not reassess whether a contract is or contains a lease, lease classification and initial direct costs. The Company also utilized the practical expedient to not separate lease and non-lease components for all leases. Adoption of the updated guidance resulted in the following changes to the Condensed Consolidated Balance Sheet on January 1, 2019: (In millions) Balance as of December 31, 2018 Adjustments Due to Adoption of Topic 842 Balance as of January 1, 2019 Property and equipment at cost (less accumulated depreciation) $ 324 $ 2 $ 326 Other assets 1,208 237 1,445 Other liabilities 3,089 239 3,328 As of January 1, 2019 , operating lease right-of-use (ROU) assets, included within Other assets, were reduced by accrued rent and lease incentives of $75 million previously classified as Other liabilities. The updated guidance did not impact the Condensed Consolidated Statements of Operations. See Note K to the Condensed Consolidated Financial Statements for additional information regarding leases. Accounting Standards Pending Adoption In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments-Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments . The updated accounting guidance requires changes to the recognition of credit losses on financial instruments not accounted for at fair value through net income. The guidance is effective for interim and annual periods beginning after December 15, 2019. The guidance will be applied using a modified retrospective approach with the cumulative effect recognized as an adjustment to retained earnings. A prospective transition approach is required for debt securities that have recognized an other-than-temporary impairment prior to the effective date. The Company is currently evaluating the effect the guidance will have on the Company's financial statements, but does not expect the impact to be material. The primary changes will be the use of the expected credit loss model for mortgage loans, reinsurance and insurance receivables and other financing receivables and the use of the allowance method rather than the write-down method for credit losses within the available-for-sale fixed maturities portfolio. The expected credit loss model will require a financial asset to be presented at the net amount expected to be collected. The allowance method for available-for-sale debt securities will allow the Company to record reversals of credit losses if the estimate of credit losses declines. The Company is currently in the process of evaluating existing impairment methodology, developing models to comply with the new guidance and accumulating all of the necessary internal and external information required to measure credit losses under the expected credit loss model. The Company is implementing changes to the information systems to assist with the accounting, including the recording of the allowance. The Company is also evaluating additional changes to processes to meet the reporting and disclosure requirements of the new guidance. In August 2018, the FASB issued ASU 2018-12, Financial Services-Insurance (Topic 944): Targeted Improvements to the Accounting for Long-Duration Contracts . The updated accounting guidance requires changes to the measurement and disclosure of long-duration contracts. The guidance requires entities to annually update cash flow assumptions, including morbidity and persistency, and update discount rate assumptions quarterly using an upper-medium grade fixed-income instrument yield. The effect of changes in cash flow assumptions will be recorded in Net income and the effect of changes in discount rate assumptions will be recorded in Other comprehensive income. This guidance is effective for interim and annual periods beginning after December 15, 2020; however the FASB has approved a one year deferral of the effective date. The guidance requires restatement of prior periods presented. Early adoption is permitted. The Company is currently evaluating the method and timing of adoption and the effect the updated guidance will have on its financial statements. The annual updating of cash flow assumptions is expected to increase income statement volatility. The quarterly change in discount rate is expected to increase volatility in the Company’s stockholders' equity, but that will be somewhat mitigated because Shadow Adjustments are eliminated under the new guidance. While the requirements of the new guidance represent a material change from existing GAAP, the underlying economics of the business and related cash flows are unchanged.

General General (Tables)

General General (Tables)	9 Months Ended
	Sep. 30, 2019
Accounting Policies [Abstract]
Schedule of new accounting pronouncements and changes in accounting principles	Adoption of the updated guidance resulted in the following changes to the Condensed Consolidated Balance Sheet on January 1, 2019: (In millions) Balance as of December 31, 2018 Adjustments Due to Adoption of Topic 842 Balance as of January 1, 2019 Property and equipment at cost (less accumulated depreciation) $ 324 $ 2 $ 326 Other assets 1,208 237 1,445 Other liabilities 3,089 239 3,328

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2019
Investments [Abstract]
Net investment income	The significant components of Net investment income are presented in the following table. Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Fixed maturity securities $ 452 $ 449 $ 1,362 $ 1,339 Equity securities 16 10 62 32 Limited partnership investments 12 23 125 93 Mortgage loans 13 11 37 36 Short term investments 8 6 27 18 Trading portfolio 2 1 6 6 Other — 1 2 4 Gross investment income 503 501 1,621 1,528 Investment expense (16 ) (14 ) (48 ) (45 ) Net investment income $ 487 $ 487 $ 1,573 $ 1,483
Net realized investment gains (losses)	Net investment gains (losses) are presented in the following table. Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Net investment gains (losses): Fixed maturity securities: Gross gains $ 34 $ 42 $ 98 $ 148 Gross losses (31 ) (32 ) (104 ) (116 ) Net investment gains (losses) on fixed maturity securities 3 10 (6 ) 32 Equity securities 7 2 60 (23 ) Derivatives (2 ) 1 (13 ) 10 Short term investments and other (1 ) 1 (21 ) 6 Net investment gains (losses) $ 7 $ 14 $ 20 $ 25
Components of net other than temporary impairment losses recognized in earnings by asset type	The components of Other-than-temporary impairment (OTTI) losses recognized in earnings by asset type are presented in the following table. Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Fixed maturity securities available-for-sale: Corporate and other bonds $ 12 $ 1 $ 24 $ 6 Asset-backed 2 2 10 3 OTTI losses recognized in earnings $ 14 $ 3 $ 34 $ 9
Summary of fixed maturity and equity securities	The following tables present a summary of fixed maturity securities. September 30, 2019 Cost or Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Unrealized OTTI Losses (Gains) (In millions) Fixed maturity securities available-for-sale: Corporate and other bonds $ 19,806 $ 2,263 $ 42 $ 22,027 $ — States, municipalities and political subdivisions 9,154 1,641 — 10,795 — Asset-backed: Residential mortgage-backed 4,718 157 1 4,874 (23 ) Commercial mortgage-backed 2,066 117 3 2,180 1 Other asset-backed 1,884 46 4 1,926 (3 ) Total asset-backed 8,668 320 8 8,980 (25 ) U.S. Treasury and obligations of government-sponsored enterprises 124 7 — 131 — Foreign government 491 20 — 511 — Redeemable preferred stock 10 — — 10 — Total fixed maturity securities available-for-sale 38,253 4,251 50 42,454 $ (25 ) Total fixed maturity securities trading 5 — — 5 Total fixed maturity securities $ 38,258 $ 4,251 $ 50 $ 42,459 December 31, 2018 Cost or Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Estimated Fair Value Unrealized OTTI Losses (Gains) (In millions) Fixed maturity securities available-for-sale: Corporate and other bonds $ 18,764 $ 791 $ 395 $ 19,160 $ — States, municipalities and political subdivisions 9,681 1,076 9 10,748 — Asset-backed: Residential mortgage-backed 4,815 68 57 4,826 (20 ) Commercial mortgage-backed 2,200 28 32 2,196 — Other asset-backed 1,975 11 24 1,962 — Total asset-backed 8,990 107 113 8,984 (20 ) U.S. Treasury and obligations of government-sponsored enterprises 156 3 — 159 — Foreign government 480 5 4 481 — Redeemable preferred stock 10 — — 10 — Total fixed maturity securities available-for-sale 38,081 1,982 521 39,542 $ (20 ) Total fixed maturity securities trading 4 — — 4 Total fixed maturity securities $ 38,085 $ 1,982 $ 521 $ 39,546
Securities in a gross unrealized loss position	The following tables present the estimated fair value and gross unrealized losses of fixed maturity securities in a gross unrealized loss position by the length of time in which the securities have continuously been in that position. Less than 12 Months 12 Months or Longer Total September 30, 2019 Estimated Gross Estimated Gross Estimated Gross Unrealized Losses (In millions) Fixed maturity securities available-for-sale: Corporate and other bonds $ 890 $ 26 $ 200 $ 16 $ 1,090 $ 42 States, municipalities and political subdivisions 20 — 2 — 22 — Asset-backed: Residential mortgage-backed 150 — 38 1 188 1 Commercial mortgage-backed 83 2 26 1 109 3 Other asset-backed 416 3 6 1 422 4 Total asset-backed 649 5 70 3 719 8 U.S. Treasury and obligations of government-sponsored enterprises 14 — 4 — 18 — Foreign government 17 — 2 — 19 — Total $ 1,590 $ 31 $ 278 $ 19 $ 1,868 $ 50 Less than 12 Months 12 Months or Longer Total December 31, 2018 Estimated Gross Estimated Gross Estimated Gross (In millions) Fixed maturity securities available-for-sale: Corporate and other bonds $ 8,543 $ 340 $ 825 $ 55 $ 9,368 $ 395 States, municipalities and political subdivisions 517 8 5 1 522 9 Asset-backed: Residential mortgage-backed 1,932 23 1,119 34 3,051 57 Commercial mortgage-backed 728 10 397 22 1,125 32 Other asset-backed 834 21 125 3 959 24 Total asset-backed 3,494 54 1,641 59 5,135 113 U.S. Treasury and obligations of government-sponsored enterprises 21 — 19 — 40 — Foreign government 114 2 124 2 238 4 Total $ 12,689 $ 404 $ 2,614 $ 117 $ 15,303 $ 521
Activity related to the pretax fixed maturity credit loss component reflected within retained earnings for securities still held for which a portion of an OTTI loss was recognized in OCI	The following table presents the activity related to the pretax credit loss component reflected in Retained earnings on fixed maturity securities still held as of September 30, 2019 and 2018 for which a portion of an OTTI loss was recognized in Other comprehensive income (loss). Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Beginning balance of credit losses on fixed maturity securities $ 16 $ 21 $ 18 $ 27 Reductions for securities sold during the period — (2 ) (2 ) (8 ) Ending balance of credit losses on fixed maturity securities $ 16 $ 19 $ 16 $ 19
Contractual maturity	The following table presents available-for-sale fixed maturity securities by contractual maturity. September 30, 2019 December 31, 2018 (In millions) Cost or Amortized Cost Estimated Fair Value Cost or Amortized Cost Estimated Fair Value Due in one year or less $ 1,071 $ 1,091 $ 1,350 $ 1,359 Due after one year through five years 10,992 11,470 7,979 8,139 Due after five years through ten years 13,694 14,711 16,859 16,870 Due after ten years 12,496 15,182 11,893 13,174 Total $ 38,253 $ 42,454 $ 38,081 $ 39,542

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Assets and liabilities measured at fair value on a recurring basis	Assets and liabilities measured at fair value on a recurring basis are presented in the following tables. Corporate bonds and other includes obligations of the U.S. Treasury, government-sponsored enterprises, foreign governments and redeemable preferred stock. September 30, 2019 Total Assets/Liabilities at Fair Value (In millions) Level 1 Level 2 Level 3 Assets Fixed maturity securities: Corporate bonds and other $ 161 $ 22,095 $ 428 $ 22,684 States, municipalities and political subdivisions — 10,795 — 10,795 Asset-backed — 8,784 196 8,980 Total fixed maturity securities 161 41,674 624 42,459 Equity securities: Common stock 114 — 6 120 Non-redeemable preferred stock 52 653 16 721 Total equity securities 166 653 22 841 Short term and other 288 1,089 — 1,377 Total assets $ 615 $ 43,416 $ 646 $ 44,677 Liabilities Other liabilities $ — $ 9 $ — $ 9 Total liabilities $ — $ 9 $ — $ 9 December 31, 2018 Total Assets/Liabilities at Fair Value (In millions) Level 1 Level 2 Level 3 Assets Fixed maturity securities: Corporate bonds and other $ 196 $ 19,396 $ 222 $ 19,814 States, municipalities and political subdivisions — 10,748 — 10,748 Asset-backed — 8,787 197 8,984 Total fixed maturity securities 196 38,931 419 39,546 Equity securities: Common stock 144 — 4 148 Non-redeemable preferred stock 48 570 14 632 Total equity securities 192 570 18 780 Short term and other 216 949 — 1,165 Total assets $ 604 $ 40,450 $ 437 $ 41,491 Liabilities Other liabilities $ — $ (4 ) $ — $ (4 ) Total liabilities $ — $ (4 ) $ — $ (4 )
Table of reconciliation for assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs	The tables below present a reconciliation for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3). Level 3 (In millions) Corporate bonds and other States, municipalities and political subdivisions Asset-backed Equity securities Total Balance as of July 1, 2019 $ 338 $ — $ 193 $ 22 $ 553 Total realized and unrealized investment gains (losses): Reported in Net investment gains (losses) — — — — — Reported in Other comprehensive income (loss) 14 — 1 — 15 Total realized and unrealized investment gains (losses) 14 — 1 — 15 Purchases 79 — 22 — 101 Sales — — — — — Settlements (3 ) — (4 ) — (7 ) Transfers into Level 3 — — — — — Transfers out of Level 3 — — (16 ) — (16 ) Balance as of September 30, 2019 $ 428 $ — $ 196 $ 22 $ 646 Unrealized gains (losses) on Level 3 assets and liabilities held as of September 30, 2019 recognized in Net income (loss) in the period $ — $ — $ — $ — $ — Unrealized gains (losses) on Level 3 assets and liabilities held as of September 30, 2019 recognized in Other comprehensive income (loss) in the period 14 — 2 — 16 Level 3 (In millions) Corporate bonds and other States, municipalities and political subdivisions Asset-backed Equity securities Total Balance as of July 1, 2018 $ 94 $ 1 $ 273 $ 17 $ 385 Total realized and unrealized investment gains (losses): Reported in Net investment gains (losses) — — (2 ) 1 (1 ) Reported in Other comprehensive income (loss) — — — — — Total realized and unrealized investment gains (losses) — — (2 ) 1 (1 ) Purchases 67 — 55 — 122 Sales — — — — — Settlements (3 ) (1 ) (25 ) — (29 ) Transfers into Level 3 30 — 29 — 59 Transfers out of Level 3 — — (32 ) — (32 ) Balance as of September 30, 2018 $ 188 $ — $ 298 $ 18 $ 504 Unrealized gains (losses) on Level 3 assets and liabilities held as of September 30, 2018 recognized in Net income (loss) in the period $ — $ — $ (2 ) $ 1 $ (1 ) Unrealized gains (losses) on Level 3 assets and liabilities held as of September 30, 2018 recognized in Other comprehensive income (loss) in the period — — 1 — 1 Level 3 (In millions) Corporate bonds and other States, municipalities and political subdivisions Asset-backed Equity securities Total Balance as of January 1, 2019 $ 222 $ — $ 197 $ 18 $ 437 Total realized and unrealized investment gains (losses): Reported in Net investment gains (losses) — — — 2 2 Reported in Other comprehensive income (loss) 34 — 8 — 42 Total realized and unrealized investment gains (losses) 34 — 8 2 44 Purchases 211 — 42 2 255 Sales — — — — — Settlements (7 ) — (12 ) — (19 ) Transfers into Level 3 — — 45 — 45 Transfers out of Level 3 (32 ) — (84 ) — (116 ) Balance as of September 30, 2019 $ 428 $ — $ 196 $ 22 $ 646 Unrealized gains (losses) on Level 3 assets and liabilities held as of September 30, 2019 recognized in Net income (loss) in the period $ — $ — $ — $ 2 $ 2 Unrealized gains (losses) on Level 3 assets and liabilities held as of September 30, 2019 recognized in Other comprehensive income (loss) in the period 29 — 9 — 38 Level 3 (In millions) Corporate bonds and other States, municipalities and political subdivisions Asset-backed Equity securities Total Balance as of January 1, 2018 $ 98 $ 1 $ 335 $ 20 $ 454 Total realized and unrealized investment gains (losses): Reported in Net investment gains (losses) (1 ) — 5 (2 ) 2 Reported in Other comprehensive income (loss) (1 ) — (6 ) — (7 ) Total realized and unrealized investment gains (losses) (2 ) — (1 ) (2 ) (5 ) Purchases 69 — 126 — 195 Sales (5 ) — (72 ) — (77 ) Settlements (7 ) (1 ) (37 ) — (45 ) Transfers into Level 3 35 — 42 — 77 Transfers out of Level 3 — — (95 ) — (95 ) Balance as of September 30, 2018 $ 188 $ — $ 298 $ 18 $ 504 Unrealized gains (losses) on Level 3 assets and liabilities held as of September 30, 2018 recognized in Net income (loss) in the period $ — $ — $ (2 ) $ (2 ) $ (4 ) Unrealized gains (losses) on Level 3 assets and liabilities held as of September 30, 2018 recognized in Other comprehensive income (loss) in the period (2 ) — (2 ) — (4 )
Quantitative information about significant unobservable inputs in the fair value measurement of level 3 assets	The following tables present quantitative information about the significant unobservable inputs utilized by the Company in the fair value measurements of Level 3 assets. Valuations for assets and liabilities not presented in the tables below are primarily based on broker/dealer quotes for which there is a lack of transparency as to inputs used to develop the valuations. The quantitative detail of these unobservable inputs is neither provided nor reasonably available to the Company. The weighted average rate is calculated based on fair value. September 30, 2019 Estimated Fair Value (In millions) Valuation Technique(s) Unobservable Input(s) Range (Weighted Average) Fixed maturity securities $ 496 Discounted cash flow Credit spread 1% - 6% (2%) December 31, 2018 Estimated Fair Value Valuation Technique(s) Unobservable Input(s) Range (Weighted Average) Fixed maturity securities $ 228 Discounted cash flow Credit spread 1% - 12% (3%)
Carrying amount and estimated fair value of financial instrument assets and liabilities not measured at fair value	The carrying amount and estimated fair value of the Company's financial assets and liabilities which are not measured at fair value on the Condensed Consolidated Balance Sheets are presented in the following tables. September 30, 2019 Carrying Amount Estimated Fair Value (In millions) Level 1 Level 2 Level 3 Total Assets Mortgage loans $ 923 $ — $ — $ 950 $ 950 Note receivable 21 — — 21 21 Liabilities Long term debt $ 2,678 $ — $ 2,905 $ — $ 2,905 December 31, 2018 Carrying Estimated Fair Value (In millions) Level 1 Level 2 Level 3 Total Assets Mortgage loans $ 839 $ — $ — $ 827 $ 827 Note receivable 35 — — 35 35 Liabilities Long term debt $ 2,680 $ — $ 2,731 $ — $ 2,731

Claim and Claim Adjustment Ex_2

Claim and Claim Adjustment Expense and Future Policy Benefit Reserves (Tables)	9 Months Ended
	Sep. 30, 2019
Net Incurred Claim and Claim Adjustment Expense [Line Items]
Schedule of liability for unpaid claims and claims adjustment expense	The following table presents a reconciliation between beginning and ending claim and claim adjustment expense reserves, including claim and claim adjustment expense reserves of the Life & Group segment. For the nine months ended September 30 (In millions) 2019 2018 Reserves, beginning of year: Gross $ 21,984 $ 22,004 Ceded 4,019 3,934 Net reserves, beginning of year 17,965 18,070 Net incurred claim and claim adjustment expenses: Provision for insured events of current year 3,968 3,866 Increase (decrease) in provision for insured events of prior years (65 ) (173 ) Amortization of discount 143 136 Total net incurred (1) 4,046 3,829 Net payments attributable to: Current year events (599 ) (658 ) Prior year events (3,547 ) (3,415 ) Total net payments (4,146 ) (4,073 ) Foreign currency translation adjustment and other 29 (80 ) Net reserves, end of period 17,894 17,746 Ceded reserves, end of period 3,702 3,858 Gross reserves, end of period $ 21,596 $ 21,604 (1) Total net incurred above does not agree to Insurance claims and policyholders' benefits as reflected on the Condensed Consolidated Statements of Operations due to amounts related to retroactive reinsurance deferred gain accounting, uncollectible reinsurance and loss deductible receivables, and benefit expenses related to future policy benefits, which are not reflected in the table above.
Net prior year development	The following table presents development recorded for the Specialty, Commercial, International and Corporate & Other segments. Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Pretax (favorable) unfavorable development: Specialty $ (20 ) $ (53 ) $ (58 ) $ (127 ) Commercial 35 (5 ) 15 (27 ) International 1 (2 ) 14 (4 ) Corporate & Other — (2 ) — (2 ) Total pretax (favorable) unfavorable development $ 16 $ (62 ) $ (29 ) $ (160 )
Specialty
Net Incurred Claim and Claim Adjustment Expense [Line Items]
Net prior year claim and allocated claim adjustment expense reserve development	The following table presents further detail of the development recorded for the Specialty segment. Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Pretax (favorable) unfavorable development: Medical Professional Liability $ 29 $ 15 $ 59 $ 38 Other Professional Liability and Management Liability (18 ) (45 ) (37 ) (113 ) Surety (43 ) (20 ) (83 ) (50 ) Warranty — (1 ) (7 ) (7 ) Other 12 (2 ) 10 5 Total pretax (favorable) unfavorable development $ (20 ) $ (53 ) $ (58 ) $ (127 )
Commercial
Net Incurred Claim and Claim Adjustment Expense [Line Items]
Net prior year claim and allocated claim adjustment expense reserve development	The following table presents further detail of the development recorded for the Commercial segment. Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Pretax (favorable) unfavorable development: Commercial Auto $ (16 ) $ 1 $ (24 ) $ — General Liability 43 (5 ) 36 13 Workers' Compensation 7 (2 ) 2 (14 ) Property and Other 1 1 1 (26 ) Total pretax (favorable) unfavorable development $ 35 $ (5 ) $ 15 $ (27 )
International
Net Incurred Claim and Claim Adjustment Expense [Line Items]
Net prior year claim and allocated claim adjustment expense reserve development	The following table presents further detail of the development recorded for the International segment. Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Pretax (favorable) unfavorable development: Casualty $ (6 ) $ (5 ) $ (11 ) $ (11 ) Property 3 2 14 14 Energy and Marine 1 (5 ) 9 (10 ) Specialty (1) 3 6 2 3 Total pretax (favorable) unfavorable development $ 1 $ (2 ) $ 14 $ (4 ) (1) Effective January 1, 2019 the Healthcare and Technology line of business has been absorbed within the Specialty line of business in the International segment. Prior period information has been conformed to the new line of business presentation.
CNAF Consolidated
Net Incurred Claim and Claim Adjustment Expense [Line Items]
Impact of loss portfolio transfer on the consolidated statement of operations	The following table presents the impact of the Loss Portfolio Transfer on the Condensed Consolidated Statements of Operations. Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Additional amounts ceded under LPT: Net A&EP adverse development before consideration of LPT $ — $ — $ — $ 113 Provision for uncollectible third-party reinsurance on A&EP — — — (16 ) Total additional amounts ceded under LPT — — — 97 Retroactive reinsurance benefit recognized (7 ) (12 ) (43 ) (84 ) Pretax impact of deferred retroactive reinsurance $ (7 ) $ (12 ) $ (43 ) $ 13

Benefit Plans (Tables)

Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2019
Retirement Benefits [Abstract]
Components of net periodic cost (benefit)	The components of net periodic pension cost (benefit) are presented in the following table. Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Net periodic pension cost (benefit) Service cost $ — $ — $ — $ — Non-service cost (benefit): Interest cost on projected benefit obligation 25 23 75 70 Expected return on plan assets (36 ) (40 ) (107 ) (120 ) Amortization of net actuarial (gain) loss 10 10 30 28 Settlement loss — — — 5 Total non-service cost (benefit) (1 ) (7 ) (2 ) (17 ) Total net periodic pension cost (benefit) $ (1 ) $ (7 ) $ (2 ) $ (17 )

Accumulated Other Comprehensi_2

Accumulated Other Comprehensive Income (Loss) by Component (Tables)	9 Months Ended
	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract]
Accumulated other comprehensive income (loss) by component	The tables below display the changes in Accumulated other comprehensive income (loss) by component. (In millions) Net unrealized gains (losses) on investments with OTTI losses Net unrealized gains (losses) on other investments Pension and postretirement benefits Cumulative foreign currency translation adjustment Total Balance as of July 1, 2019 $ 20 $ 1,023 $ (760 ) $ (163 ) $ 120 Other comprehensive income (loss) before reclassifications — 44 — (29 ) 15 Amounts reclassified from accumulated other comprehensive income (loss) net of tax (expense) benefit of $-, $-, $2, $- and $2 — 3 (7 ) — (4 ) Other comprehensive income (loss) net of tax (expense) benefit of $-, $(11), $(2), $- and $(13) — 41 7 (29 ) 19 Balance as of September 30, 2019 $ 20 $ 1,064 $ (753 ) $ (192 ) $ 139 (In millions) Net unrealized gains (losses) on investments with OTTI losses Net unrealized gains (losses) on other investments Pension and postretirement benefits Cumulative foreign currency translation adjustment Total Balance as of July 1, 2018 $ 20 $ 271 $ (758 ) $ (138 ) $ (605 ) Other comprehensive income (loss) before reclassifications (1 ) (148 ) — — (149 ) Amounts reclassified from accumulated other comprehensive income (loss) net of tax (expense) benefit of $-, $(2), $1, $- and $(1) — 10 (7 ) — 3 Other comprehensive income (loss) net of tax (expense) benefit of $-, $42, $(1), $- and $41 (1 ) (158 ) 7 — (152 ) Balance as of September 30, 2018 $ 19 $ 113 $ (751 ) $ (138 ) $ (757 ) (In millions) Net unrealized gains (losses) on investments with OTTI losses Net unrealized gains (losses) on other investments Pension and postretirement benefits Cumulative foreign currency translation adjustment Total Balance as of January 1, 2019 $ 16 $ 61 $ (775 ) $ (180 ) $ (878 ) Other comprehensive income (loss) before reclassifications 3 999 (1 ) (12 ) 989 Amounts reclassified from accumulated other comprehensive income (loss) net of tax (expense) benefit of $-, $1, $6, $- and $7 (1 ) (4 ) (23 ) — (28 ) Other comprehensive income (loss) net of tax (expense) benefit of $(2), $(266), $(6), $- and $(274) 4 1,003 22 (12 ) 1,017 Balance as of September 30, 2019 $ 20 $ 1,064 $ (753 ) $ (192 ) $ 139 (In millions) Net unrealized gains (losses) on investments with OTTI losses Net unrealized gains (losses) on other investments Pension and postretirement benefits Cumulative foreign currency translation adjustment Total Balance as of January 1, 2018 $ 30 $ 859 $ (775 ) $ (98 ) $ 16 Other comprehensive income (loss) before reclassifications (12 ) (718 ) — (40 ) (770 ) Amounts reclassified from accumulated other comprehensive income (loss) net of tax (expense) benefit of $-, $(7), $6, $- and $(1) (1 ) 28 (24 ) — 3 Other comprehensive income (loss) net of tax (expense) benefit of $3, $197, $(6), $- and $194 (11 ) (746 ) 24 (40 ) (773 ) Balance as of September 30, 2018 $ 19 $ 113 $ (751 ) $ (138 ) $ (757 )
Reclassification out of accumulated other comprehensive income	Amounts reclassified from Accumulated other comprehensive income (loss) shown above are reported in Net income (loss) as follows: Component of AOCI Consolidated Statements of Operations Line Item Affected by Reclassifications Net unrealized gains (losses) on investments with OTTI losses Net investment gains (losses) Net unrealized gains (losses) on other investments Net investment gains (losses) Pension and postretirement benefits Other operating expenses and Insurance claims and policyholders' benefits

Business Segments (Tables)

Business Segments (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting [Abstract]
Significant components of the Company's continuing operations and selected balance sheet items	The Company's results of operations and selected balance sheet items by segment are presented in the following tables. Three months ended September 30, 2019 International Life & Corporate Eliminations Total (In millions) Operating revenues Net earned premiums $ 712 $ 813 $ 236 $ 130 $ — $ (1 ) $ 1,890 Net investment income 121 136 17 207 6 — 487 Non-insurance warranty revenue 292 — — — — — 292 Other revenues 1 10 (1 ) (1 ) 1 (1 ) 9 Total operating revenues 1,126 959 252 336 7 (2 ) 2,678 Claims, benefits and expenses Net incurred claims and benefits 411 564 163 476 (7 ) — 1,607 Policyholders’ dividends 2 5 — — — — 7 Amortization of deferred acquisition costs 155 134 56 — — — 345 Non-insurance warranty expense 278 — — — — — 278 Other insurance related expenses 71 123 35 29 — (1 ) 257 Other expenses 13 9 7 1 35 (1 ) 64 Total claims, benefits and expenses 930 835 261 506 28 (2 ) 2,558 Core income (loss) before income tax 196 124 (9 ) (170 ) (21 ) — 120 Income tax (expense) benefit on core income (loss) (43 ) (27 ) — 48 4 — (18 ) Core income (loss) $ 153 $ 97 $ (9 ) $ (122 ) $ (17 ) $ — 102 Net investment gains (losses) 7 Income tax (expense) benefit on net investment gains (losses) (2 ) Net investment gains (losses), after tax 5 Net income $ 107 Three months ended September 30, 2018 International Life & Corporate Eliminations Total (In millions) Operating revenues Net earned premiums $ 684 $ 782 $ 255 $ 133 $ — $ (1 ) $ 1,853 Net investment income 124 144 14 200 5 — 487 Non-insurance warranty revenue 258 — — — — — 258 Other revenues — 8 1 (1 ) 2 — 10 Total operating revenues 1,066 934 270 332 7 (1 ) 2,608 Claims, benefits and expenses Net incurred claims and benefits 373 496 172 277 (12 ) — 1,306 Policyholders’ dividends 1 5 — — — — 6 Amortization of deferred acquisition costs 153 127 57 — — — 337 Non-insurance warranty expense 235 — — — — — 235 Other insurance related expenses 68 133 36 31 (1 ) (1 ) 266 Other expenses 11 10 3 2 44 — 70 Total claims, benefits and expenses 841 771 268 310 31 (1 ) 2,220 Core income (loss) before income tax 225 163 2 22 (24 ) — 388 Income tax (expense) benefit on core income (loss) (48 ) (36 ) (1 ) 10 4 — (71 ) Core income (loss) $ 177 $ 127 $ 1 $ 32 $ (20 ) $ — 317 Net investment gains (losses) 14 Income tax (expense) benefit on net investment gains (losses) (1 ) Net investment gains (losses), after tax 13 Net deferred tax asset remeasurement 6 Net income $ 336 Nine months ended September 30, 2019 Specialty Commercial International Life & Group Corporate & Other Eliminations Total (In millions) Operating revenues Net earned premiums $ 2,061 $ 2,339 $ 729 $ 390 $ — $ (2 ) $ 5,517 Net investment income 410 480 47 616 20 — 1,573 Non-insurance warranty revenue 858 — — — — — 858 Other revenues 1 20 — — 5 (4 ) 22 Total operating revenues 3,330 2,839 776 1,006 25 (6 ) 7,970 Claims, benefits and expenses Net incurred claims and benefits 1,198 1,581 472 1,093 (40 ) — 4,304 Policyholders’ dividends 4 15 — — — — 19 Amortization of deferred acquisition costs 454 391 180 — — — 1,025 Non-insurance warranty expense 801 — — — — — 801 Other insurance related expenses 217 372 94 87 (2 ) (2 ) 766 Other expenses 37 27 14 5 108 (4 ) 187 Total claims, benefits and expenses 2,711 2,386 760 1,185 66 (6 ) 7,102 Core income (loss) before income tax 619 453 16 (179 ) (41 ) — 868 Income tax (expense) benefit on core income (loss) (136 ) (97 ) (2 ) 74 7 — (154 ) Core income (loss) $ 483 $ 356 $ 14 $ (105 ) $ (34 ) $ — 714 Net investment gains (losses) 20 Income tax (expense) benefit on net investment gains (losses) (7 ) Net investment gains (losses), after tax 13 Net income $ 727 September 30, 2019 (In millions) Reinsurance receivables $ 599 $ 759 $ 242 $ 394 $ 2,098 $ — $ 4,092 Insurance receivables 992 1,243 260 8 1 — 2,504 Deferred acquisition costs 314 264 90 — — — 668 Goodwill 117 — 28 — — — 145 Deferred non-insurance warranty acquisition expense 2,772 — — — — — 2,772 Insurance reserves Claim and claim adjustment expenses 5,285 8,610 1,802 3,707 2,192 — 21,596 Unearned premiums 2,329 1,679 475 126 — (1 ) 4,608 Future policy benefits — — — 12,305 — — 12,305 Deferred non-insurance warranty revenue 3,707 — — — — — 3,707 Nine months ended September 30, 2018 Specialty Commercial International Life & Group Corporate & Other Eliminations Total (In millions) Operating revenues Net earned premiums $ 2,039 $ 2,278 $ 739 $ 398 $ — $ (1 ) $ 5,453 Net investment income 376 450 43 598 16 — 1,483 Non-insurance warranty revenue 744 — — — — — 744 Other revenues 1 24 — — 2 (1 ) 26 Total operating revenues 3,160 2,752 782 996 18 (2 ) 7,706 Claims, benefits and expenses Net incurred claims and benefits 1,124 1,434 480 907 15 — 3,960 Policyholders’ dividends 3 15 — — — — 18 Amortization of deferred acquisition costs 447 375 170 — — — 992 Non-insurance warranty expense 676 — — — — — 676 Other insurance related expenses 202 386 102 91 (1 ) (1 ) 779 Other expenses 34 31 6 5 153 (1 ) 228 Total claims, benefits and expenses 2,486 2,241 758 1,003 167 (2 ) 6,653 Core income (loss) before income tax 674 511 24 (7 ) (149 ) — 1,053 Income tax (expense) benefit on core income (loss) (143 ) (108 ) (7 ) 43 30 — (185 ) Core income (loss) $ 531 $ 403 $ 17 $ 36 $ (119 ) $ — 868 Net investment gains (losses) 25 Income tax (expense) benefit on net investment gains (losses) (2 ) Net investment gains (losses), after tax 23 Net deferred tax asset remeasurement 6 Net income $ 897 December 31, 2018 (In millions) Reinsurance receivables $ 649 $ 795 $ 250 $ 414 $ 2,347 $ — $ 4,455 Insurance receivables 947 1,277 284 9 (152 ) — 2,365 Deferred acquisition costs 308 230 95 — — — 633 Goodwill 117 — 29 — — — 146 Deferred non-insurance warranty acquisition expense 2,513 — — — — — 2,513 Insurance reserves Claim and claim adjustment expenses 5,465 8,743 1,750 3,601 2,425 — 21,984 Unearned premiums 2,132 1,454 475 122 — — 4,183 Future policy benefits — — — 10,597 — — 10,597 Deferred non-insurance warranty revenue 3,402 — — — — — 3,402
Revenues by line of business	The following table presents operating revenue by line of business for each reportable segment. Periods ended September 30 Three Months Nine Months (In millions) 2019 2018 2019 2018 Specialty Management & Professional Liability $ 638 $ 616 $ 1,903 $ 1,867 Surety 156 153 446 427 Warranty & Alternative Risks 332 297 981 866 Specialty revenues 1,126 1,066 3,330 3,160 Commercial Middle Market 560 530 1,652 1,555 Small Business 115 125 351 364 Other Commercial Insurance 284 279 836 833 Commercial revenues 959 934 2,839 2,752 International Canada 70 66 204 187 Europe 91 94 270 273 Hardy 91 110 302 322 International revenues 252 270 776 782 Life & Group revenues 336 332 1,006 996 Corporate & Other revenues 7 7 25 18 Eliminations (2 ) (1 ) (6 ) (2 ) Total operating revenues 2,678 2,608 7,970 7,706 Net investment gains (losses) 7 14 20 25 Total revenues $ 2,685 $ 2,622 $ 7,990 $ 7,731

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2019
Leases [Abstract]
Assets and liabilities, lessee	The following table presents operating lease ROU assets and lease liabilities. (In millions) September 30, 2019 Operating lease ROU assets $ 223 Operating lease liabilities 304
Maturities of operating lease liabilities	The following table presents the maturities of operating lease liabilities as of September 30, 2019 . (In millions) Operating Leases 2019 (Excluding the nine months ended September 30, 2019) $ 6 2020 39 2021 42 2022 39 2023 34 Thereafter 213 Total lease payments 373 Less: Discount (69 ) Total operating lease liabilities $ 304
Lease terms and discount rates	The following table presents the weighted average remaining lease term for operating leases and weighted average discount rate used in calculating operating lease right-of-use assets. September 30, 2019 Weighted average remaining lease term 10.9 years Weighted average discount rate 3.4 %
Schedule of future minimum rental payments for operating leases	The following table presents the expected future minimum lease payments to be made under non-cancelable operating leases as of December 31, 2018 . (In millions) Future Minimum Lease Payments 2019 $ 35 2020 39 2021 41 2022 38 2023 32 Thereafter 200 Total $ 385

General (Narrative) (Details)

General (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other assets	$ (1,571)	$ (1,445)	$ (1,208)
CNAF Consolidated | Loews
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Noncontrolling interest, ownership percentage by parent	89.00%
Adjustments Due to Adoption of Topic 842
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Other assets	$ 75	$ (237)

General (Adoption of Updated Gu

General (Adoption of Updated Guidance) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property and equipment at cost (less accumulated depreciation)	$ 293	$ 326	$ 324
Other assets	1,571	1,445	1,208
Other liabilities	3,433	3,328	$ 3,089
Adjustments Due to Adoption of Topic 842
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Property and equipment at cost (less accumulated depreciation)		2
Other assets	$ (75)	237
Other liabilities		$ 239

Earnings (Loss) Per Share (Deta

Earnings (Loss) Per Share (Details) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Earnings Per Share [Abstract]
Incremental common shares attributable to dilutive effect of share-based payment arrangements (in shares)	1,000,000	900,000	920,000	925,000
Antidilutive securities excluded from computation of earnings per share, amount (in shares)	1,000	1,000	3,000	3,000
Number of repurchased shares (in shares)			415,695
Cost of repurchased stock			$ 18,000,000		$ 0

Investments (Net investment inc

Investments (Net investment income) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Net Investment Income [Line Items]
Gross investment income	$ 503	$ 501	$ 1,621	$ 1,528
Investment expense	(16)	(14)	(48)	(45)
Net investment income	487	487	1,573	1,483
Fixed maturity securities
Net Investment Income [Line Items]
Gross investment income	452	449	1,362	1,339
Equity securities
Net Investment Income [Line Items]
Gross investment income	16	10	62	32
Limited partnership investments
Net Investment Income [Line Items]
Gross investment income	12	23	125	93
Mortgage loans
Net Investment Income [Line Items]
Gross investment income	13	11	37	36
Short term investments
Net Investment Income [Line Items]
Gross investment income	8	6	27	18
Trading portfolio
Net Investment Income [Line Items]
Gross investment income	2	1	6	6
Other
Net Investment Income [Line Items]
Gross investment income	$ 0	$ 1	$ 2	$ 4

Investments (Narrative) (Detail

Investments (Narrative) (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Gain (Loss) on Securities [Line Items]
Reduction of net unrealized gains on investments included in AOCI due to shadow adjustments	$ 2,237,000,000		$ 2,237,000,000		$ 1,078,000,000
Derivative, notional amount	170,000,000		170,000,000		172,000,000
Derivative liability	(9,000,000)		(9,000,000)
Derivative asset, fair value, gross asset					$ 4,000,000
Commitments to purchase or fund privately placed debt securities	865,000,000		865,000,000
Commitments to sell various privately placed debt securities	90,000,000		90,000,000
Common Stock
Gain (Loss) on Securities [Line Items]
Equity securities, FV-NI, gain (loss)	5,000,000		26,000,000
Preferred stock
Gain (Loss) on Securities [Line Items]
Equity securities, FV-NI, gain (loss)	7,000,000	$ 2,000,000	60,000,000	$ (23,000,000)
5.875%, face amount of $500, due August 15, 2020
Gain (Loss) on Securities [Line Items]
Equity securities, FV-NI, gain (loss)		$ 2,000,000	(21,000,000)
Face amount	$ 500,000,000		$ 500,000,000

Investments (Net realized inves

Investments (Net realized investment gains (losses)) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Fixed maturity securities:
Gross gains	$ 34	$ 42	$ 98	$ 148
Gross losses	(31)	(32)	(104)	(116)
Net investment gains (losses) on fixed maturity securities	3	10	(6)	32
Equity securities	7	2	60	(23)
Derivatives	(2)	1	(13)	10
Short term investments and other	(1)	1	(21)	6
Net investment gains	$ 7	$ 14	$ 20	$ 25

Investments (Components of othe

Investments (Components of other-than-temporary impairment losses recognized in earnings) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Debt Securities, Available-for-sale [Line Items]
Total fixed maturity securities available-for-sale	$ 14	$ 3	$ 34	$ 9
Corporate and other bonds
Debt Securities, Available-for-sale [Line Items]
Total fixed maturity securities available-for-sale	12	1	24	6
Asset-backed
Debt Securities, Available-for-sale [Line Items]
Total fixed maturity securities available-for-sale	$ 2	$ 2	$ 10	$ 3

Investments (Summary of fixed m

Investments (Summary of fixed maturity and equity securities) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Fixed maturity securities available-for-sale:
Cost or Amortized Cost	$ 38,253	$ 38,081
Gross Unrealized Gains	4,251	1,982
Gross Unrealized Losses	50	521
Estimated Fair Value	42,454	39,542
Total fixed maturity securities trading
Debt securities, amortized cost	38,258	38,085
Debt securities	42,459	39,546
Corporate and other bonds
Fixed maturity securities available-for-sale:
Cost or Amortized Cost	19,806	18,764
Gross Unrealized Gains	2,263	791
Gross Unrealized Losses	42	395
Estimated Fair Value	22,027	19,160
Total fixed maturity securities trading
Debt securities	22,684	19,814
Unrealized OTTI Losses (Gains)	0	0
States, municipalities and political subdivisions
Fixed maturity securities available-for-sale:
Cost or Amortized Cost	9,154	9,681
Gross Unrealized Gains	1,641	1,076
Gross Unrealized Losses	0	9
Estimated Fair Value	10,795	10,748
Total fixed maturity securities trading
Debt securities	10,795	10,748
Unrealized OTTI Losses (Gains)	0	0
Residential mortgage-backed
Fixed maturity securities available-for-sale:
Cost or Amortized Cost	4,718	4,815
Gross Unrealized Gains	157	68
Gross Unrealized Losses	1	57
Estimated Fair Value	4,874	4,826
Total fixed maturity securities trading
Unrealized OTTI Losses (Gains)	(23)	(20)
Commercial mortgage-backed
Fixed maturity securities available-for-sale:
Cost or Amortized Cost	2,066	2,200
Gross Unrealized Gains	117	28
Gross Unrealized Losses	3	32
Estimated Fair Value	2,180	2,196
Total fixed maturity securities trading
Unrealized OTTI Losses (Gains)	1	0
Other asset-backed
Fixed maturity securities available-for-sale:
Cost or Amortized Cost	1,884	1,975
Gross Unrealized Gains	46	11
Gross Unrealized Losses	4	24
Estimated Fair Value	1,926	1,962
Total fixed maturity securities trading
Unrealized OTTI Losses (Gains)	(3)	0
Asset-backed
Fixed maturity securities available-for-sale:
Cost or Amortized Cost	8,668	8,990
Gross Unrealized Gains	320	107
Gross Unrealized Losses	8	113
Estimated Fair Value	8,980	8,984
Total fixed maturity securities trading
Debt securities	8,980	8,984
Unrealized OTTI Losses (Gains)	(25)	(20)
U.S. Treasury and obligations of government-sponsored enterprises
Fixed maturity securities available-for-sale:
Cost or Amortized Cost	124	156
Gross Unrealized Gains	7	3
Gross Unrealized Losses	0	0
Estimated Fair Value	131	159
Total fixed maturity securities trading
Unrealized OTTI Losses (Gains)	0	0
Foreign government
Fixed maturity securities available-for-sale:
Cost or Amortized Cost	491	480
Gross Unrealized Gains	20	5
Gross Unrealized Losses	0	4
Estimated Fair Value	511	481
Total fixed maturity securities trading
Unrealized OTTI Losses (Gains)	0	0
Redeemable preferred stock
Fixed maturity securities available-for-sale:
Cost or Amortized Cost	10	10
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	10	10
Total fixed maturity securities trading
Unrealized OTTI Losses (Gains)	0	0
Fixed maturity securities
Fixed maturity securities available-for-sale:
Cost or Amortized Cost	38,253	38,081
Gross Unrealized Gains	4,251	1,982
Gross Unrealized Losses	50	521
Estimated Fair Value	42,454	39,542
Total fixed maturity securities trading
Unrealized OTTI Losses (Gains)	(25)	(20)
Total fixed maturity securities trading
Total fixed maturity securities trading
Cost or amortized cost, trading securities	5	4
Estimated fair value, trading securities	$ 5	$ 4

Investments (Securities in a gr

Investments (Securities in a gross unrealized loss position) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Corporate and other bonds
Debt Securities, Available-for-sale [Line Items]
Estimated Fair Value, Less than 12 months	$ 890	$ 8,543
Gross Unrealized Losses, Less than 12 Months	26	340
Estimated Fair Value, 12 Months or Longer	200	825
Gross Unrealized Losses, 12 Months or Longer	16	55
Estimated Fair Value, Total	1,090	9,368
Gross Unrealized Losses, Total	42	395
States, municipalities and political subdivisions
Debt Securities, Available-for-sale [Line Items]
Estimated Fair Value, Less than 12 months	20	517
Gross Unrealized Losses, Less than 12 Months	0	8
Estimated Fair Value, 12 Months or Longer	2	5
Gross Unrealized Losses, 12 Months or Longer	0	1
Estimated Fair Value, Total	22	522
Gross Unrealized Losses, Total	0	9
Residential mortgage-backed
Debt Securities, Available-for-sale [Line Items]
Estimated Fair Value, Less than 12 months	150	1,932
Gross Unrealized Losses, Less than 12 Months	0	23
Estimated Fair Value, 12 Months or Longer	38	1,119
Gross Unrealized Losses, 12 Months or Longer	1	34
Estimated Fair Value, Total	188	3,051
Gross Unrealized Losses, Total	1	57
Commercial mortgage-backed
Debt Securities, Available-for-sale [Line Items]
Estimated Fair Value, Less than 12 months	83	728
Gross Unrealized Losses, Less than 12 Months	2	10
Estimated Fair Value, 12 Months or Longer	26	397
Gross Unrealized Losses, 12 Months or Longer	1	22
Estimated Fair Value, Total	109	1,125
Gross Unrealized Losses, Total	3	32
Other asset-backed
Debt Securities, Available-for-sale [Line Items]
Estimated Fair Value, Less than 12 months	416	834
Gross Unrealized Losses, Less than 12 Months	3	21
Estimated Fair Value, 12 Months or Longer	6	125
Gross Unrealized Losses, 12 Months or Longer	1	3
Estimated Fair Value, Total	422	959
Gross Unrealized Losses, Total	4	24
Asset-backed
Debt Securities, Available-for-sale [Line Items]
Estimated Fair Value, Less than 12 months	649	3,494
Gross Unrealized Losses, Less than 12 Months	5	54
Estimated Fair Value, 12 Months or Longer	70	1,641
Gross Unrealized Losses, 12 Months or Longer	3	59
Estimated Fair Value, Total	719	5,135
Gross Unrealized Losses, Total	8	113
U.S. Treasury and obligations of government-sponsored enterprises
Debt Securities, Available-for-sale [Line Items]
Estimated Fair Value, Less than 12 months	14	21
Gross Unrealized Losses, Less than 12 Months	0	0
Estimated Fair Value, 12 Months or Longer	4	19
Gross Unrealized Losses, 12 Months or Longer	0	0
Estimated Fair Value, Total	18	40
Gross Unrealized Losses, Total	0	0
Foreign government
Debt Securities, Available-for-sale [Line Items]
Estimated Fair Value, Less than 12 months	17	114
Gross Unrealized Losses, Less than 12 Months	0	2
Estimated Fair Value, 12 Months or Longer	2	124
Gross Unrealized Losses, 12 Months or Longer	0	2
Estimated Fair Value, Total	19	238
Gross Unrealized Losses, Total	0	4
Fixed maturity securities
Debt Securities, Available-for-sale [Line Items]
Estimated Fair Value, Less than 12 months	1,590	12,689
Gross Unrealized Losses, Less than 12 Months	31	404
Estimated Fair Value, 12 Months or Longer	278	2,614
Gross Unrealized Losses, 12 Months or Longer	19	117
Estimated Fair Value, Total	1,868	15,303
Gross Unrealized Losses, Total	$ 50	$ 521

Investments (Activity related t

Investments (Activity related to the pretax fixed maturity credit loss component reflected within retained earnings for securities still held for which a portion of an OTTI loss was recognized in OCI) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Roll Forward]
Beginning balance of credit losses on fixed maturity securities	$ 16	$ 21	$ 18	$ 27
Reductions for securities sold during the period	0	(2)	(2)	(8)
Ending balance of credit losses on fixed maturity securities	$ 16	$ 19	$ 16	$ 19

Investments (Contractual maturi

Investments (Contractual maturity) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Investments [Abstract]
Due in one year or less, cost or amortized cost	$ 1,071	$ 1,350
Due after one year through five years, cost or amortized cost	10,992	7,979
Due after five years through ten years, cost or amortized cost	13,694	16,859
Due after ten years, cost or amortized cost	12,496	11,893
Cost or Amortized Cost	38,253	38,081
Due in one year or less, estimated fair value	1,091	1,359
Due after one year through five years, estimated fair value	11,470	8,139
Due after five years through ten years, estimated fair value	14,711	16,870
Due after ten years, estimated fair value	15,182	13,174
Total Estimated Fair Value	$ 42,454	$ 39,542

Fair Value (Assets and liabilit

Fair Value (Assets and liabilities measured at fair value on a recurring basis) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Fixed maturity securities:
Debt securities	$ 42,459	$ 39,546
Equity securities:
Equity securities	841	780
Short term and other	1,377	1,165
Total assets	44,677	41,491
Liabilities
Other liabilities	9	(4)
Total liabilities	9	(4)
Corporate and other bonds
Fixed maturity securities:
Debt securities	22,684	19,814
States, municipalities and political subdivisions
Fixed maturity securities:
Debt securities	10,795	10,748
Asset-backed
Fixed maturity securities:
Debt securities	8,980	8,984
Common Stock
Equity securities:
Equity securities	120	148
Preferred stock
Equity securities:
Equity securities	721	632
Level 1
Fixed maturity securities:
Debt securities	161	196
Equity securities:
Equity securities	166	192
Short term and other	288	216
Total assets	615	604
Liabilities
Other liabilities	0	0
Total liabilities	0	0
Level 1 | Corporate and other bonds
Fixed maturity securities:
Debt securities	161	196
Level 1 | States, municipalities and political subdivisions
Fixed maturity securities:
Debt securities	0	0
Level 1 | Asset-backed
Fixed maturity securities:
Debt securities	0	0
Level 1 | Common Stock
Equity securities:
Equity securities	114	144
Level 1 | Preferred stock
Equity securities:
Equity securities	52	48
Level 2
Fixed maturity securities:
Debt securities	41,674	38,931
Equity securities:
Equity securities	653	570
Short term and other	1,089	949
Total assets	43,416	40,450
Liabilities
Other liabilities	9	(4)
Total liabilities	9	(4)
Level 2 | Corporate and other bonds
Fixed maturity securities:
Debt securities	22,095	19,396
Level 2 | States, municipalities and political subdivisions
Fixed maturity securities:
Debt securities	10,795	10,748
Level 2 | Asset-backed
Fixed maturity securities:
Debt securities	8,784	8,787
Level 2 | Common Stock
Equity securities:
Equity securities	0	0
Level 2 | Preferred stock
Equity securities:
Equity securities	653	570
Level 3
Fixed maturity securities:
Debt securities	624	419
Equity securities:
Equity securities	22	18
Short term and other	0	0
Total assets	646	437
Liabilities
Other liabilities	0	0
Total liabilities	0	0
Level 3 | Corporate and other bonds
Fixed maturity securities:
Debt securities	428	222
Level 3 | States, municipalities and political subdivisions
Fixed maturity securities:
Debt securities	0	0
Level 3 | Asset-backed
Fixed maturity securities:
Debt securities	196	197
Level 3 | Common Stock
Equity securities:
Equity securities	6	4
Level 3 | Preferred stock
Equity securities:
Equity securities	$ 16	$ 14

Fair Value (Table of reconcilia

Fair Value (Table of reconciliation for assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of beginning of the period	$ 553	$ 385	$ 437	$ 454
Reported in Other comprehensive income (loss)	15	0	42	(7)
Total realized and unrealized investment gains (losses)	15	(1)	44	(5)
Purchases	101	122	255	195
Sales	0	0	0	(77)
Settlements	(7)	(29)	(19)	(45)
Transfers into Level 3	0	59	45	77
Transfers out of Level 3	(16)	(32)	(116)	(95)
Balance as of end of the period	646	504	646	504
Unrealized gains (losses) on Level 3 assets and liabilities recognized in Net income (loss) in the period	0	(1)	2	(4)
Unrealized gains (losses) on Level 3 assets and liabilities recognized in Other comprehensive income (loss) in the period	16	1	38	(4)
Corporate and other bonds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of beginning of the period	338	94	222	98
Reported in Other comprehensive income (loss)	14	0	34	(1)
Total realized and unrealized investment gains (losses)	14	0	34	(2)
Purchases	79	67	211	69
Sales	0	0	0	(5)
Settlements	(3)	(3)	(7)	(7)
Transfers into Level 3	0	30	0	35
Transfers out of Level 3	0	0	(32)	0
Balance as of end of the period	428	188	428	188
Unrealized gains (losses) on Level 3 assets and liabilities recognized in Net income (loss) in the period	0	0	0	0
Unrealized gains (losses) on Level 3 assets and liabilities recognized in Other comprehensive income (loss) in the period	14	0	29	(2)
States, municipalities and political subdivisions
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of beginning of the period	0	1	0	1
Reported in Other comprehensive income (loss)	0	0	0	0
Total realized and unrealized investment gains (losses)	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Settlements	0	(1)	0	(1)
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Balance as of end of the period	0	0	0	0
Unrealized gains (losses) on Level 3 assets and liabilities recognized in Net income (loss) in the period	0	0	0	0
Unrealized gains (losses) on Level 3 assets and liabilities recognized in Other comprehensive income (loss) in the period	0	0	0	0
Asset-backed
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of beginning of the period	193	273	197	335
Reported in Other comprehensive income (loss)	1	0	8	(6)
Total realized and unrealized investment gains (losses)	1	(2)	8	(1)
Purchases	22	55	42	126
Sales	0	0	0	(72)
Settlements	(4)	(25)	(12)	(37)
Transfers into Level 3	0	29	45	42
Transfers out of Level 3	(16)	(32)	(84)	(95)
Balance as of end of the period	196	298	196	298
Unrealized gains (losses) on Level 3 assets and liabilities recognized in Net income (loss) in the period	0	(2)	0	(2)
Unrealized gains (losses) on Level 3 assets and liabilities recognized in Other comprehensive income (loss) in the period	2	1	9	(2)
Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance as of beginning of the period	22	17	18	20
Reported in Other comprehensive income (loss)	0	0	0	0
Total realized and unrealized investment gains (losses)	0	1	2	(2)
Purchases	0	0	2	0
Sales	0	0	0	0
Settlements	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
Balance as of end of the period	22	18	22	18
Unrealized gains (losses) on Level 3 assets and liabilities recognized in Net income (loss) in the period	0	1	2	(2)
Unrealized gains (losses) on Level 3 assets and liabilities recognized in Other comprehensive income (loss) in the period	0	0	0	0
Reported in Net investment gains (losses)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Reported in Net investment gains (losses)	0	(1)	2	2
Reported in Net investment gains (losses) | Corporate and other bonds
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Reported in Net investment gains (losses)	0	0	0	(1)
Reported in Net investment gains (losses) | States, municipalities and political subdivisions
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Reported in Net investment gains (losses)	0	0	0	0
Reported in Net investment gains (losses) | Asset-backed
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Reported in Net investment gains (losses)	0	(2)	0	5
Reported in Net investment gains (losses) | Equity securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Reported in Net investment gains (losses)	$ 0	$ 1	$ 2	$ (2)

Fair Value (Narrative) (Details

Fair Value (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Other invested assets overseas deposit	$ 55	$ 48

Fair Value (Quantitative inform

Fair Value (Quantitative information about significant unobservable inputs in the fair value measurement of level 3 assets) (Details) $ in Millions	Sep. 30, 2019USD ($)	Dec. 31, 2018USD ($)
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Estimated fair value	$ 44,677	$ 41,491
Fixed maturity securities | Discounted cash flow
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Estimated fair value	$ 496	$ 228
Measurement Input, Credit Spread | Discounted cash flow | Minimum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Debt securities, available-for-sale, measurement Input	0.01	0.01
Measurement Input, Credit Spread | Discounted cash flow | Maximum
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Debt securities, available-for-sale, measurement Input	0.06	0.12
Measurement Input, Credit Spread | Discounted cash flow | Weighted Average
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Debt securities, available-for-sale, measurement Input	0.02	0.03

Fair Value (Carrying amount and

Fair Value (Carrying amount and estimated fair value of financial instrument assets and liabilities which are not measured at fair value) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Financial Assets [Abstract]
Mortgage loans	$ 923	$ 839
Financial Liabilities [Abstract]
Long term debt	2,678	2,680
Carrying Amount
Financial Assets [Abstract]
Mortgage loans	923	839
Note receivable	21	35
Financial Liabilities [Abstract]
Long term debt	2,678	2,680
Estimated Fair Value
Financial Assets [Abstract]
Mortgage loans	950	827
Note receivable	21	35
Financial Liabilities [Abstract]
Long term debt	2,905	2,731
Level 1 | Estimated Fair Value
Financial Assets [Abstract]
Mortgage loans	0	0
Note receivable	0	0
Financial Liabilities [Abstract]
Long term debt	0	0
Level 2 | Estimated Fair Value
Financial Assets [Abstract]
Mortgage loans	0	0
Note receivable	0	0
Financial Liabilities [Abstract]
Long term debt	2,905	2,731
Level 3 | Estimated Fair Value
Financial Assets [Abstract]
Mortgage loans	950	827
Note receivable	21	35
Financial Liabilities [Abstract]
Long term debt	$ 0	$ 0

Claim and Claim Adjustment Ex_3

Claim and Claim Adjustment Expense and Future Policy Benefit Reserves (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Dec. 31, 2010
Liability for Claims and Claims Adjustment Expense [Line Items]
Catastrophe losses net of reinsurance	$ 32	$ 46	$ 128	$ 106
Asbestos and Environmental Reserves
Liability for Claims and Claims Adjustment Expense [Line Items]
Net A&EP claim and allocated claim adjustment expense reserves ceded to NICO						$ 1,600
Aggregate limit under A&EP Loss Portfolio Transfer						4,000
A&EP claim and allocated claim adjustment expense reserves ceded under existing third party reinsurance contracts transferred to NICO under A&EP Loss Portfolio Transfer						1,200
Reinsurance premium paid to NICO under A&EP Loss Portfolio Transfer						2,000
Net reinsurance receivables transferred to NICO under A&EP Loss Portfolio Transfer						215
Total consideration paid to NICO under AEP Loss Portfolio Transfer						$ 2,200
Net A&EP adverse development before consideration of LPT	0	$ 0	0	$ 113
Cumulative amounts ceded under AEP Loss Portfolio Transfer	3,100		3,100		$ 3,100
Deferred reinsurance benefit yet to be recognized	331		331		374
Fair value of collateral trust account established by NICO under A&EP Loss Portfolio Transfer	$ 3,300		$ 3,300		$ 2,700

Claim and Claim Adjustment Ex_4

Claim and Claim Adjustment Expense and Future Policy Benefit Reserves (Reconciliation of claim and claim adjustment expense reserves) (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Reserves, beginning of year: [Abstract]
Gross	$ 21,984	$ 22,004
Ceded	4,019	3,934
Net reserves, beginning of year	17,965	18,070
Net incurred claim and claim adjustment expenses:
Provision for insured events of current year	3,968	3,866
Increase (decrease) in provision for insured events of prior years	(65)	(173)
Amortization of discount	143	136
Total net incurred	4,046	3,829
Net payments attributable to:
Current year events	(599)	(658)
Prior year events	(3,547)	(3,415)
Total net payments	(4,146)	(4,073)
Foreign currency translation adjustment and other	29	(80)
Net reserves, end of period	17,894	17,746
Ceded reserves, end of period	3,702	3,858
Gross reserves, end of period	$ 21,596	$ 21,604

Claim and Claim Adjustment Ex_5

Claim and Claim Adjustment Expense and Future Policy Benefit Reserves (Net prior year development) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Pretax (favorable) unfavorable premium development, excluding Life & Group	$ 16	$ (62)	$ (29)	$ (160)
Specialty
Segment Reporting Information [Line Items]
Pretax (favorable) unfavorable premium development, excluding Life & Group	(20)	(53)	(58)	(127)
Commercial
Segment Reporting Information [Line Items]
Pretax (favorable) unfavorable premium development, excluding Life & Group	35	(5)	15	(27)
International
Segment Reporting Information [Line Items]
Pretax (favorable) unfavorable premium development, excluding Life & Group	1	(2)	14	(4)
Corporate & Other
Segment Reporting Information [Line Items]
Pretax (favorable) unfavorable premium development, excluding Life & Group	$ 0	$ (2)	$ 0	$ (2)

Claim and Claim Adjustment Ex_6

Claim and Claim Adjustment Expense and Future Policy Benefit Reserves (Specialty - Net prior year claim and allocated claim adjustment expense reserve development) (Details) - Specialty - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Liability for Claims and Claims Adjustment Expense [Line Items]
Medical Professional Liability	$ 29	$ 15	$ 59	$ 38
Other Professional Liability and Management Liability	(18)	(45)	(37)	(113)
Surety	(43)	(20)	(83)	(50)
Warranty	0	(1)	(7)	(7)
Other	12	(2)	10	5
Total pretax (favorable) unfavorable development	$ (20)	$ (53)	$ (58)	$ (127)

Claim and Claim Adjustment Ex_7

Claim and Claim Adjustment Expense and Future Policy Benefit Reserves (Commercial - Net prior year claim and allocated claim adjustment expense reserve development) (Details) - Commercial - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Liability for Claims and Claims Adjustment Expense [Line Items]
Commercial Auto	$ (16)	$ 1	$ (24)	$ 0
General Liability	43	(5)	36	13
Workers' Compensation	7	(2)	2	(14)
Property and Other	1	1	1	(26)
Total pretax (favorable) unfavorable development	$ 35	$ (5)	$ 15	$ (27)

Claim and Claim Adjustment Ex_8

Claim and Claim Adjustment Expense and Future Policy Benefit Reserves (International - Net prior year claim and allocated claim adjustment expense reserve development) (Details) - International - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Liability for Claims and Claims Adjustment Expense [Line Items]
Casualty	$ (6)	$ (5)	$ (11)	$ (11)
Property	3	2	14	14
Energy and Marine	1	(5)	9	(10)
Specialty	3	6	2	3
Total pretax (favorable) unfavorable development	$ 1	$ (2)	$ 14	$ (4)

Claim and Claim Adjustment Ex_9

Claim and Claim Adjustment Expense and Future Policy Benefit Reserves (Impact of Loss Portfolio Transfer on the Consolidated Statement of Operations) (Details) - Asbestos and Environmental Reserves - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Liability for Claims and Claims Adjustment Expense [Line Items]
Net A&EP adverse development before consideration of LPT	$ 0	$ 0	$ 0	$ 113
Provision for uncollectible third-party reinsurance on A&EP	0	0	0	(16)
Total additional amounts ceded under LPT	0	0	0	97
Retroactive reinsurance benefit recognized	(7)	(12)	(43)	(84)
Pretax impact of deferred retroactive reinsurance	$ (7)	$ (12)	$ (43)	$ 13

Claim and Claim Adjustment E_10

Claim and Claim Adjustment Expense and Future Policy Benefit Reserves (Life & Group Policyholder Reserves) (Details) - USD ($) $ in Millions	3 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Liability for Claims and Claims Adjustment Expense [Abstract]
Liability for unpaid claims and claims adjustment expense, period increase (decrease)	$ 56	$ 31
Premium deficiency testing expense, long-duration contract, amount	$ 216

Legal Proceedings, Contingenc_2

Legal Proceedings, Contingencies and Guarantees (Narrative) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Guarantee Obligations
Legal Proceedings, Commitments and Contingencies, and Guarantees [Line Items]
Guarantor obligations, maximum exposure, undiscounted	$ 1,700
Guarantee and Indemnification
Legal Proceedings, Commitments and Contingencies, and Guarantees [Line Items]
Guarantor obligations, current carrying value	$ 5	$ 5

Benefit Plans (Narrative) (Deta

Benefit Plans (Narrative) (Details) - Pension Benefits - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Total non-service cost (benefit) (less than)	$ (1)	$ (7)	$ (2)	$ (17)
Insurance Claims and Policyholder's Benefits, Including Policyholder's Dividends
Total non-service cost (benefit) (less than)	(1)	(3)	(1)	(6)
Other Expense
Total non-service cost (benefit) (less than)	$ (1)	$ (4)	$ (1)	$ (11)

Benefit Plans (Components of ne

Benefit Plans (Components of net periodic cost (benefit)) (Details) - Pension Benefits - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 0	$ 0	$ 0	$ 0
Interest cost on projected benefit obligation	25	23	75	70
Expected return on plan assets	(36)	(40)	(107)	(120)
Amortization of net actuarial (gain) loss	10	10	30	28
Settlement loss	0	0	0	5
Total non-service cost (benefit)	(1)	(7)	(2)	(17)
Total net periodic pension cost (benefit)	$ (1)	$ (7)	$ (2)	$ (17)

Accumulated Other Comprehensi_3

Accumulated Other Comprehensive Income (Loss) by Component Schedule of Accumulated Other Comprehensive Income (Loss) by Component (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Total stockholder's equity at beginning of period			$ 11,217
Other comprehensive income (loss) before reclassifications	$ 15	$ (149)	989	$ (770)
Amounts reclassified from accumulated other comprehensive income (loss) net of tax	(4)	3	(28)	3
Other comprehensive income (loss) after tax (expense) benefit	19	(152)	1,017	(773)
Total stockholder's equity at end of period	12,123	11,510	12,123	11,510
Reclassification from AOCI, tax (expense) benefit	2	(1)	7	(1)
Tax (expense) benefit on other comprehensive income (loss)	(13)	41	(274)	194
Net unrealized gains (losses) on investments with OTTI losses
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Total stockholder's equity at beginning of period	20	20	16	30
Other comprehensive income (loss) before reclassifications	0	(1)	3	(12)
Amounts reclassified from accumulated other comprehensive income (loss) net of tax	0	0	(1)	(1)
Other comprehensive income (loss) after tax (expense) benefit	0	(1)	4	(11)
Total stockholder's equity at end of period	20	19	20	19
Reclassification from AOCI, tax (expense) benefit	0	0	0	0
Tax (expense) benefit on other comprehensive income (loss)	0	0	(2)	3
Net unrealized gains (losses) on other investments
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Total stockholder's equity at beginning of period	1,023	271	61	859
Other comprehensive income (loss) before reclassifications	44	(148)	999	(718)
Amounts reclassified from accumulated other comprehensive income (loss) net of tax	3	10	(4)	28
Other comprehensive income (loss) after tax (expense) benefit	41	(158)	1,003	(746)
Total stockholder's equity at end of period	1,064	113	1,064	113
Reclassification from AOCI, tax (expense) benefit	0	(2)	1	(7)
Tax (expense) benefit on other comprehensive income (loss)	(11)	42	(266)	197
Pension and postretirement benefits
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Total stockholder's equity at beginning of period	(760)	(758)	(775)	(775)
Other comprehensive income (loss) before reclassifications	0	0	(1)	0
Amounts reclassified from accumulated other comprehensive income (loss) net of tax	(7)	(7)	(23)	(24)
Other comprehensive income (loss) after tax (expense) benefit	7	7	22	24
Total stockholder's equity at end of period	(753)	(751)	(753)	(751)
Reclassification from AOCI, tax (expense) benefit	2	1	6	6
Tax (expense) benefit on other comprehensive income (loss)	(2)	(1)	(6)	(6)
Cumulative foreign currency translation adjustment
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Total stockholder's equity at beginning of period	(163)	(138)	(180)	(98)
Other comprehensive income (loss) before reclassifications	(29)	0	(12)	(40)
Amounts reclassified from accumulated other comprehensive income (loss) net of tax	0	0	0	0
Other comprehensive income (loss) after tax (expense) benefit	(29)	0	(12)	(40)
Total stockholder's equity at end of period	(192)	(138)	(192)	(138)
Reclassification from AOCI, tax (expense) benefit	0	0	0	0
Tax (expense) benefit on other comprehensive income (loss)	0	0	0	0
Accumulated other comprehensive income (loss)
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Total stockholder's equity at beginning of period	120	(605)	(878)	16
Total stockholder's equity at end of period	$ 139	$ (757)	$ 139	$ (757)

Business Segments (Narrative) (

Business Segments (Narrative) (Details)	9 Months Ended
	Sep. 30, 2019segment
Core Segments - Specialty, Commercial and International
Segment Reporting Information [Line Items]
Number of operating segments	3
Non-Core Segments, Life & Group Non-Core and Corporate and Other Non-Core
Segment Reporting Information [Line Items]
Number of operating segments	2

Business Segments (Income State

Business Segments (Income Statement Information) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Operating revenues
Net earned premiums	$ 1,890	$ 1,853	$ 5,517	$ 5,453
Net investment income	487	487	1,573	1,483
Non-insurance warranty revenue	292	258	858	744
Other revenues	9	10	22	26
Total operating revenues	2,678	2,608	7,970	7,706
Claims, Benefits and Expenses
Net incurred claims and benefits	1,607	1,306	4,304	3,960
Policyholders’ dividends	7	6	19	18
Amortization of deferred acquisition costs	345	337	1,025	992
Non-insurance warranty expense	278	235	801	676
Other insurance related expenses	257	266	766	779
Other expenses	64	70	187	228
Total claims, benefits and expenses	2,558	2,220	7,102	6,653
Core income (loss) before income tax	120	388	868	1,053
Income tax (expense) benefit on core income (loss)	(18)	(71)	(154)	(185)
Core income (loss)	102	317	714	868
Net investment gains (losses)	7	14	20	25
Income tax (expense) benefit on net investment gains (losses)	(2)	(1)	(7)	(2)
Net investment gains (losses), after tax	5	13	13	23
Deferred Income Tax Expense (Benefit), Remeasurement of Deferred Tax Asset		6		6
Net income	107	336	727	897
Operating Segments | Specialty
Operating revenues
Net earned premiums	712	684	2,061	2,039
Net investment income	121	124	410	376
Non-insurance warranty revenue	292	258	858	744
Other revenues	1	0	1	1
Total operating revenues	1,126	1,066	3,330	3,160
Claims, Benefits and Expenses
Net incurred claims and benefits	411	373	1,198	1,124
Policyholders’ dividends	2	1	4	3
Amortization of deferred acquisition costs	155	153	454	447
Non-insurance warranty expense	278	235	801	676
Other insurance related expenses	71	68	217	202
Other expenses	13	11	37	34
Total claims, benefits and expenses	930	841	2,711	2,486
Core income (loss) before income tax	196	225	619	674
Income tax (expense) benefit on core income (loss)	(43)	(48)	(136)	(143)
Core income (loss)	153	177	483	531
Operating Segments | Commercial
Operating revenues
Net earned premiums	813	782	2,339	2,278
Net investment income	136	144	480	450
Non-insurance warranty revenue	0	0	0	0
Other revenues	10	8	20	24
Total operating revenues	959	934	2,839	2,752
Claims, Benefits and Expenses
Net incurred claims and benefits	564	496	1,581	1,434
Policyholders’ dividends	5	5	15	15
Amortization of deferred acquisition costs	134	127	391	375
Non-insurance warranty expense	0	0	0	0
Other insurance related expenses	123	133	372	386
Other expenses	9	10	27	31
Total claims, benefits and expenses	835	771	2,386	2,241
Core income (loss) before income tax	124	163	453	511
Income tax (expense) benefit on core income (loss)	(27)	(36)	(97)	(108)
Core income (loss)	97	127	356	403
Operating Segments | International
Operating revenues
Net earned premiums	236	255	729	739
Net investment income	17	14	47	43
Non-insurance warranty revenue	0	0	0	0
Other revenues	(1)	1	0	0
Total operating revenues	252	270	776	782
Claims, Benefits and Expenses
Net incurred claims and benefits	163	172	472	480
Policyholders’ dividends	0	0	0	0
Amortization of deferred acquisition costs	56	57	180	170
Non-insurance warranty expense	0	0	0	0
Other insurance related expenses	35	36	94	102
Other expenses	7	3	14	6
Total claims, benefits and expenses	261	268	760	758
Core income (loss) before income tax	(9)	2	16	24
Income tax (expense) benefit on core income (loss)	0	(1)	(2)	(7)
Core income (loss)	(9)	1	14	17
Operating Segments | Life & Group
Operating revenues
Net earned premiums	130	133	390	398
Net investment income	207	200	616	598
Non-insurance warranty revenue	0	0	0	0
Other revenues	(1)	(1)	0	0
Total operating revenues	336	332	1,006	996
Claims, Benefits and Expenses
Net incurred claims and benefits	476	277	1,093	907
Policyholders’ dividends	0	0	0	0
Amortization of deferred acquisition costs	0	0	0	0
Non-insurance warranty expense	0	0	0	0
Other insurance related expenses	29	31	87	91
Other expenses	1	2	5	5
Total claims, benefits and expenses	506	310	1,185	1,003
Core income (loss) before income tax	(170)	22	(179)	(7)
Income tax (expense) benefit on core income (loss)	48	10	74	43
Core income (loss)	(122)	32	(105)	36
Operating Segments | Corporate & Other
Operating revenues
Net earned premiums	0	0	0	0
Net investment income	6	5	20	16
Non-insurance warranty revenue	0	0	0	0
Other revenues	1	2	5	2
Total operating revenues	7	7	25	18
Claims, Benefits and Expenses
Net incurred claims and benefits	(7)	(12)	(40)	15
Policyholders’ dividends	0	0	0	0
Amortization of deferred acquisition costs	0	0	0	0
Non-insurance warranty expense	0	0	0	0
Other insurance related expenses	0	(1)	(2)	(1)
Other expenses	35	44	108	153
Total claims, benefits and expenses	28	31	66	167
Core income (loss) before income tax	(21)	(24)	(41)	(149)
Income tax (expense) benefit on core income (loss)	4	4	7	30
Core income (loss)	(17)	(20)	(34)	(119)
Eliminations
Operating revenues
Net earned premiums	(1)	(1)	(2)	(1)
Net investment income	0	0	0	0
Non-insurance warranty revenue	0	0	0	0
Other revenues	(1)	0	(4)	(1)
Total operating revenues	(2)	(1)	(6)	(2)
Claims, Benefits and Expenses
Net incurred claims and benefits	0	0	0	0
Policyholders’ dividends	0	0	0	0
Amortization of deferred acquisition costs	0	0	0	0
Non-insurance warranty expense	0	0	0	0
Other insurance related expenses	(1)	(1)	(2)	(1)
Other expenses	(1)	0	(4)	(1)
Total claims, benefits and expenses	(2)	(1)	(6)	(2)
Core income (loss) before income tax	0	0	0	0
Income tax (expense) benefit on core income (loss)	0	0	0	0
Core income (loss)	$ 0	$ 0	$ 0	$ 0

Business Segments (Balance Shee

Business Segments (Balance Sheet Information) (Details) - USD ($) $ in Millions	Sep. 30, 2019	Dec. 31, 2018
Segment Reporting Information [Line Items]
Reinsurance receivables	$ 4,092	$ 4,455
Insurance receivables	2,504	2,365
Deferred acquisition costs	668	633
Goodwill	145	146
Deferred non-insurance warranty acquisition expense	2,772	2,513
Insurance reserves
Claim and claim adjustment expenses	21,596	21,984
Unearned premiums	4,608	4,183
Future policy benefits	12,305	10,597
Deferred non-insurance warranty revenue	3,707	3,402
Operating Segments | Specialty
Segment Reporting Information [Line Items]
Reinsurance receivables	599	649
Insurance receivables	992	947
Deferred acquisition costs	314	308
Goodwill	117	117
Deferred non-insurance warranty acquisition expense	2,772	2,513
Insurance reserves
Claim and claim adjustment expenses	5,285	5,465
Unearned premiums	2,329	2,132
Future policy benefits	0	0
Deferred non-insurance warranty revenue	3,707	3,402
Operating Segments | Commercial
Segment Reporting Information [Line Items]
Reinsurance receivables	759	795
Insurance receivables	1,243	1,277
Deferred acquisition costs	264	230
Goodwill	0	0
Deferred non-insurance warranty acquisition expense	0	0
Insurance reserves
Claim and claim adjustment expenses	8,610	8,743
Unearned premiums	1,679	1,454
Future policy benefits	0	0
Deferred non-insurance warranty revenue	0	0
Operating Segments | International
Segment Reporting Information [Line Items]
Reinsurance receivables	242	250
Insurance receivables	260	284
Deferred acquisition costs	90	95
Goodwill	28	29
Deferred non-insurance warranty acquisition expense	0	0
Insurance reserves
Claim and claim adjustment expenses	1,802	1,750
Unearned premiums	475	475
Future policy benefits	0	0
Deferred non-insurance warranty revenue	0	0
Operating Segments | Life & Group
Segment Reporting Information [Line Items]
Reinsurance receivables	394	414
Insurance receivables	8	9
Deferred acquisition costs	0	0
Goodwill	0	0
Deferred non-insurance warranty acquisition expense	0	0
Insurance reserves
Claim and claim adjustment expenses	3,707	3,601
Unearned premiums	126	122
Future policy benefits	12,305	10,597
Deferred non-insurance warranty revenue	0	0
Operating Segments | Corporate & Other
Segment Reporting Information [Line Items]
Reinsurance receivables	2,098	2,347
Insurance receivables	1	(152)
Deferred acquisition costs	0	0
Goodwill	0	0
Deferred non-insurance warranty acquisition expense	0	0
Insurance reserves
Claim and claim adjustment expenses	2,192	2,425
Unearned premiums	0	0
Future policy benefits	0	0
Deferred non-insurance warranty revenue	0	0
Eliminations
Segment Reporting Information [Line Items]
Reinsurance receivables	0	0
Insurance receivables	0	0
Deferred acquisition costs	0	0
Goodwill	0	0
Deferred non-insurance warranty acquisition expense	0	0
Insurance reserves
Claim and claim adjustment expenses	0	0
Unearned premiums	(1)	0
Future policy benefits	0	0
Deferred non-insurance warranty revenue	$ 0	$ 0

Business Segments (Revenues by

Business Segments (Revenues by Line of Business) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenues	$ 2,685	$ 2,622	$ 7,990	$ 7,731
Net investment gains (losses)	7	14	20	25
Operating Segments | Specialty
Revenues	1,126	1,066	3,330	3,160
Operating Segments | Commercial
Revenues	959	934	2,839	2,752
Operating Segments | International
Revenues	252	270	776	782
Operating Segments | Life & Group
Revenues	336	332	1,006	996
Operating Segments | Corporate & Other
Revenues	7	7	25	18
Eliminations
Revenues	(2)	(1)	(6)	(2)
Total operating revenues
Revenues	2,678	2,608	7,970	7,706
Management & Professional Liability | Operating Segments | Specialty
Revenues	638	616	1,903	1,867
Surety | Operating Segments | Specialty
Revenues	156	153	446	427
Warranty & Alternative Risks | Operating Segments | Specialty
Revenues	332	297	981	866
Middle Market | Operating Segments | Commercial
Revenues	560	530	1,652	1,555
Small Business | Operating Segments | Commercial
Revenues	115	125	351	364
Other Commercial Insurance | Operating Segments | Commercial
Revenues	284	279	836	833
Canada | Operating Segments | International
Revenues	70	66	204	187
Europe | Operating Segments | International
Revenues	91	94	270	273
Hardy | Operating Segments | International
Revenues	$ 91	$ 110	$ 302	$ 322

Non-Insurance Revenues from C_2

Non-Insurance Revenues from Contracts with Customers (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Revenue from Contract with Customer [Abstract]
Deferred non-insurance warranty revenue	$ 3,707		$ 3,707		$ 3,402
Contract with customer, liability, revenue recognized	$ 236	$ 200	$ 747	$ 635

Non-Insurance Revenues from C_3

Non-Insurance Revenues from Contracts with Customers (Performance Obligation) (Details) $ in Millions	Sep. 30, 2019USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-10-01
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Remaining performance obligation, amount	$ 278
Remaining performance obligation, expected timing of satisfaction, period	3 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Remaining performance obligation, amount	$ 1,000
Remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Remaining performance obligation, amount	$ 800
Remaining performance obligation, expected timing of satisfaction, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Remaining performance obligation, amount	$ 1,600
Remaining performance obligation, expected timing of satisfaction, period

Leases (Narrative) (Details)

Leases (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Leases [Abstract]
Operating lease cost	$ 9	$ 28
Variable lease cost	5	13
Operating lease payments	$ 8	25
Right of use assets obtained in exchange for lease obligations		$ 11

Leases (Assets and Liabilities)

Leases (Assets and Liabilities) (Details) $ in Millions	Sep. 30, 2019USD ($)
Leases [Abstract]
Operating lease ROU assets	$ 223
Operating lease liabilities	$ 304

Leases (Maturities of Operating

Leases (Maturities of Operating Lease Liabilities) (Details) $ in Millions	Sep. 30, 2019USD ($)
Leases [Abstract]
2019 (Excluding the nine months ended September 30, 2019)	$ 6
2020	39
2021	42
2022	39
2023	34
Thereafter	213
Total lease payments	373
Less: Discount	(69)
Total operating lease liabilities	$ 304

Leases (Lease Terms and Discoun

Leases (Lease Terms and Discount Rates) (Details)	Sep. 30, 2019
Leases [Abstract]
Weighted average remaining lease term	10 years 10 months 24 days
Weighted average discount rate	3.40%

Leases (Minimum Lease Payments)

Leases (Minimum Lease Payments) (Details) $ in Millions	Dec. 31, 2018USD ($)
Leases [Abstract]
2019	$ 35
2020	39
2021	41
2022	38
2023	32
Thereafter	200
Total	$ 385