Loews (L) 10-Q 30 Oct 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2017	Oct. 20, 2017
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	Q3
Trading Symbol	L
Entity Registrant Name	LOEWS CORP
Entity Central Index Key	60,086
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		336,631,152

Consolidated Condensed Balance

Consolidated Condensed Balance Sheets - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Assets:
Fixed maturities, amortized cost of $39,230 and $38,947	$ 42,507	$ 41,494
Equity securities, cost of $592 and $571	610	549
Limited partnership investments	3,201	3,220
Other invested assets, primarily mortgage loans	825	683
Short term investments	4,991	4,765
Total investments	52,134	50,711
Cash	416	327
Receivables	7,792	7,644
Property, plant and equipment	15,475	15,230
Goodwill	648	346
Other assets	2,419	1,736
Deferred acquisition costs of insurance subsidiaries	643	600
Total assets	79,527	76,594
Liabilities and Equity:
Claim and claim adjustment expense	22,209	22,343
Future policy benefits	11,040	10,326
Unearned premiums	4,060	3,762
Total insurance reserves	37,309	36,431
Payable to brokers	324	150
Short term debt	194	110
Long term debt	11,239	10,668
Deferred income taxes	905	636
Other liabilities	5,195	5,238
Total liabilities	55,166	53,233
Commitments and contingent liabilities
Preferred stock, $0.10 par value: Authorized - 100,000,000 shares
Common stock, $0.01 par value: Authorized - 1,800,000,000 shares Issued - 336,753,017 and 336,621,358 shares	3	3
Additional paid-in capital	3,181	3,187
Retained earnings	15,811	15,196
Accumulated other comprehensive income (loss)	32	(223)
Shareholders Equity Before Treasury Stock, Total	19,027	18,163
Less treasury stock, at cost (123,500 shares)	(6)
Total shareholders' equity	19,021	18,163
Noncontrolling interests	5,340	5,198
Total equity	24,361	23,361
Total liabilities and equity	$ 79,527	$ 76,594

Consolidated Condensed Balance3

Consolidated Condensed Balance Sheets (Parenthetical) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Statement of Financial Position [Abstract]
Fixed maturities, amortized cost	$ 39,230	$ 38,947
Equity securities, cost	$ 592	$ 571
Preferred stock, par value	$ 0.10	$ 0.10
Preferred stock, shares authorized	100,000,000	100,000,000
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	1,800,000,000	1,800,000,000
Common stock, shares issued	336,753,017	336,621,358
Treasury stock, shares	123,500

Consolidated Condensed Statemen

Consolidated Condensed Statements of Income - USD ($) shares in Thousands, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues:
Insurance premiums	$ 1,806	$ 1,767	$ 5,185	$ 5,196
Net investment income	557	561	1,639	1,570
Investment gains (losses):
Other-than-temporary impairment losses	(5)	(18)	(9)	(56)
Other net investment gains	21	63	102	74
Total investment gains	16	45	93	18
Contract drilling revenues	357	340	1,113	1,141
Other revenues	785	574	2,150	1,842
Total	3,521	3,287	10,180	9,767
Expenses:
Insurance claims and policyholders' benefits	1,480	1,202	4,053	3,949
Amortization of deferred acquisition costs	309	314	926	926
Contract drilling expenses	198	187	598	598
Other operating expenses	1,047	898	2,978	3,416
Interest	223	130	504	403
Total	3,257	2,731	9,059	9,292
Income before income tax	264	556	1,121	475
Income tax expense	(52)	(163)	(240)	(171)
Net income	212	393	881	304
Amounts attributable to noncontrolling interests	(55)	(66)	(198)	60
Net income attributable to Loews Corporation	$ 157	$ 327	$ 683	$ 364
Basic net income per share	$ 0.46	$ 0.97	$ 2.03	$ 1.08
Diluted net income per share	0.46	0.97	2.02	1.08
Dividends per share	$ 0.0625	$ 0.0625	$ 0.1875	$ 0.1875
Weighted average shares outstanding:
Shares of common stock	336,910	337,180	336,900	338,330
Dilutive potential shares of common stock	880	440	830	280
Total weighted average shares outstanding assuming dilution	337,790	337,620	337,730	338,610

Consolidated Condensed Stateme5

Consolidated Condensed Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net income	$ 212	$ 393	$ 881	$ 304
Other comprehensive income (loss), after tax Changes in:
Net unrealized gains (losses) on investments with other-than-temporary impairments	1	3	(3)	7
Net other unrealized gains on investments	23	42	167	591
Total unrealized gains on available-for-sale investments	24	45	164	598
Unrealized gains on cash flow hedges	1	1	1	2
Pension liability	11	7	26	20
Foreign currency translation	41	(24)	94	(58)
Other comprehensive income	77	29	285	562
Comprehensive income	289	422	1,166	866
Amounts attributable to noncontrolling interests	(64)	(70)	(228)	(1)
Total comprehensive income attributable to Loews Corporation	$ 225	$ 352	$ 938	$ 865

Consolidated Condensed Stateme6

Consolidated Condensed Statements of Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Common Stock Held in Treasury [Member]	Noncontrolling Interests [Member]
Beginning Balance at Dec. 31, 2015	$ 22,810	$ 3	$ 3,184	$ 14,731	$ (357)		$ 5,249
Net income	304			364			(60)
Other comprehensive income	562				501		61
Dividends paid	(177)			(63)
Dividends paid							(114)
Purchases of subsidiary stock from noncontrolling interests	(9)		3				(12)
Purchases of Loews treasury stock	(115)					$ (115)
Stock-based compensation	35		33				2
Other	(4)		(13)	(1)			10
Ending Balance at Sep. 30, 2016	23,406	3	3,207	15,031	144	(115)	5,136
Net income	393
Other comprehensive income	29
Ending Balance at Sep. 30, 2016	23,406	3	3,207	15,031	144	(115)	5,136
Beginning Balance at Dec. 31, 2016	23,361	3	3,187	15,196	(223)		5,198
Net income	881			683			198
Other comprehensive income	285				255		30
Dividends paid	(180)			(63)
Dividends paid							(117)
Purchases of Loews treasury stock	(6)					(6)
Stock-based compensation	24		(8)				32
Other	(4)		2	(5)			(1)
Ending Balance at Sep. 30, 2017	24,361	3	3,181	15,811	32	(6)	5,340
Net income	212
Other comprehensive income	77
Ending Balance at Sep. 30, 2017	$ 24,361	$ 3	$ 3,181	$ 15,811	$ 32	$ (6)	$ 5,340

Consolidated Condensed Stateme7

Consolidated Condensed Statements of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Operating Activities:
Net income	$ 881	$ 304
Adjustments to reconcile net income to net cash provided (used) by operating activities, net	959	1,676
Changes in operating assets and liabilities, net:
Receivables	19	(165)
Deferred acquisition costs	(34)	(24)
Insurance reserves	248	464
Other assets	(85)	(80)
Other liabilities	(116)	9
Trading securities	(62)	(468)
Net cash flow operating activities	1,810	1,716
Investing Activities:
Purchases of fixed maturities	(6,877)	(7,472)
Proceeds from sales of fixed maturities	4,167	4,239
Proceeds from maturities of fixed maturities	2,635	2,263
Purchases of limited partnership investments	(85)	(324)
Proceeds from sales of limited partnership investments	179	207
Purchases of property, plant and equipment	(735)	(1,185)
Acquisitions	(1,218)	(79)
Dispositions	68	277
Change in short term investments	(85)	104
Other, net	(136)	124
Net cash flow investing activities	(2,087)	(1,846)
Financing Activities:
Dividends paid	(63)	(63)
Dividends paid to noncontrolling interests	(117)	(114)
Purchases of subsidiary stock from noncontrolling interests		(8)
Purchases of Loews treasury stock	(6)	(115)
Principal payments on debt	(2,249)	(2,882)
Issuance of debt	2,808	3,226
Other, net	(16)	(2)
Net cash flow financing activities	357	42
Effect of foreign exchange rate on cash	9	(8)
Net change in cash	89	(96)
Cash, beginning of period	327	440
Cash, end of period	$ 416	$ 344

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Basis of Presentation	1. Basis of Presentation Loews Corporation is a holding company. Its subsidiaries are engaged in the following lines of business: commercial property and casualty insurance (CNA Financial Corporation (“CNA”), a 89% owned subsidiary); the operation of offshore oil and gas drilling rigs (Diamond Offshore Drilling, Inc. (“Diamond Offshore”), a 53% owned subsidiary); transportation and storage of natural gas and natural gas liquids (Boardwalk Pipeline Partners, LP (“Boardwalk Pipeline”), a 51% owned subsidiary); the operation of a chain of hotels (Loews Hotels Holding Corporation (“Loews Hotels & Co”), a wholly owned subsidiary); and the manufacture of rigid plastic packaging solutions (Consolidated Container Company LLC, a 99% owned subsidiary). Unless the context otherwise requires, the terms “Company,” “Loews” and “Registrant” as used herein mean Loews Corporation excluding its subsidiaries and the term “Net income (loss) attributable to Loews Corporation” as used herein means Net income (loss) attributable to Loews Corporation shareholders. In the opinion of management, the accompanying unaudited Consolidated Condensed Financial Statements reflect all adjustments (consisting of normal recurring accruals) necessary to present fairly the Company’s financial position as of September 30, 2017 and December 31, 2016, results of operations and comprehensive income for the three and nine months ended September 30, 2017 and 2016 and changes in shareholders’ equity and cash flows for the nine months ended September 30, 2017 and 2016. Net income (loss) for the third quarter and first nine months of each of the years is not necessarily indicative of net income (loss) for that entire year. These Consolidated Condensed Financial Statements should be read in conjunction with the Consolidated Financial Statements in the Company’s Annual Report on Form 10-K The Company presents basic and diluted net income (loss) per share on the Consolidated Condensed Statements of Income. Basic net income (loss) per share excludes dilution and is computed by dividing net income (loss) attributable to common stock by the weighted average number of common shares outstanding for the period. Diluted net income 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. 0.4 million and 3.3 million shares for the three months ended September 30, 2017 and 2016 and 0.4 million and 4.7 million shares for the nine months ended September 30, 2017 and 2016 attributable to employee stock-based compensation awards were not included in the diluted weighted average shares outstanding amounts because the effect would have been antidilutive. Accounting changes – 2016-09, Recently issued ASUs – 2014-09, In January of 2016, the FASB issued ASU 2016-01, – 825-10): available-for-sale In February of 2016, the FASB issued ASU 2016-02, 2014-09. In June of 2016, the FASB issued ASU 2016-13, available-for-sale available-for-sale In October of 2016, the FASB issued ASU 2016-16,

Acquisition of Consolidated Con

Acquisition of Consolidated Container Company	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Acquisition of Consolidated Container Company	2. Acquisition of Consolidated Container Company On May 22, 2017, the Company completed the previously announced acquisition of CCC Acquisition Holdings, Inc. for $1.2 billion, subject to closing adjustments. CCC Acquisition Holdings, Inc., through its wholly owned subsidiary, Consolidated Container Company LLC (“Consolidated Container”), is a rigid plastic packaging and recycled resins manufacturer that provides packaging solutions to end markets such as beverage, food and household chemicals through a network of manufacturing locations across North America. The results of Consolidated Container are included in the Consolidated Condensed Financial Statements since the acquisition date in the Corporate segment. For the three months ended September 30, 2017 and for the period since the acquisition date, Consolidated Container’s revenues were $202 million and $293 million and net income was not significant. For the year ended December 31, 2016, Consolidated Container reported total revenues of $788 million. The acquisition was funded with approximately $620 million of parent company cash and debt financing proceeds at Consolidated Container of $600 million, as discussed in Note 7. The following table summarizes the preliminary allocation of the purchase price to the tangible and intangible assets acquired and liabilities assumed based on their estimated fair value as of the acquisition date and is subject to change within the measurement period. The primary areas that are not yet finalized relate to working capital at closing and determination of tax bases of net assets acquired. (In millions) Cash $ 5 Property, plant and equipment 391 Goodwill 300 Other assets: Inventory 57 Customer relationships 459 Trade name 43 Other 122 Deferred income taxes (17 ) Other liabilities: Accounts payable (52 ) Pension liability (27 ) Other (58 ) $ 1,223 Customer relationships were valued using an income approach, which values the intangible asset at the present value of the related incremental after tax cash flows. The customer relationships intangible asset will be amortized over a useful life of 21 years. The trade name was valued using an income approach, which values the intangible asset based on an estimate of cost savings, or a relief from royalty. The trade name will be amortized over a useful life of 10 years. Goodwill includes value associated with the assembled workforce and Consolidated Container’s future growth and profitability. The assets acquired and liabilities assumed as part of the acquisition did not result in a step up of tax basis and approximately $94 million of goodwill is deductible for tax purposes.

Investments

Investments	9 Months Ended
	Sep. 30, 2017
Text Block [Abstract]
Investments	3. Investments Net investment income is as follows: Three Months Ended Nine Months Ended September 30, September 30, 2017 2016 2017 2016 (In millions) Fixed maturity securities $ 455 $ 457 $ 1,367 $ 1,352 Limited partnership investments 67 91 206 98 Short term investments 5 3 13 8 Equity securities 1 1 4 8 Income from trading portfolio (a) 34 11 67 113 Other 10 12 26 34 Total investment income 572 575 1,683 1,613 Investment expenses (15 ) (14 ) (44 ) (43 ) Net investment income $ 557 $ 561 $ 1,639 $ 1,570 (a) Net unrealized gains (losses) related to changes in fair value on trading securities still held were $22 and $8 for the three months ended September 30, 2017 and 2016 and $35 and $63 for the nine months ended September 30, 2017 and 2016. Investment gains (losses) are as follows: Three Months Ended Nine Months Ended September 30, September 30, 2017 2016 2017 2016 (In millions) Fixed maturity securities $ 16 $ 47 $ 92 $ 34 Equity securities (3 ) (5 ) Derivative instruments (1 ) 1 (3 ) (12 ) Short term investments and other 1 4 1 Investment gains (a) $ 16 $ 45 $ 93 $ 18 (a) Gross realized gains on available-for-sale available-for-sale The components of other-than-temporary impairment (“OTTI”) losses recognized in earnings by asset type are as follows: Three Months Ended Nine Months Ended September 30, September 30, 2017 2016 2017 2016 (In millions) Fixed maturity securities available-for-sale: Corporate and other bonds $ 4 $ 14 $ 8 $ 43 Asset-backed: Residential mortgage-backed 1 1 1 Other asset-backed 3 Total asset-backed 1 - 1 4 Total fixed maturities available-for-sale 5 14 9 47 Equity securities available-for-sale 4 9 Net OTTI losses recognized in earnings $ 5 $ 18 $ 9 $ 56 The amortized cost and fair values of securities are as follows: Cost or Gross Gross Unrealized Amortized Unrealized Unrealized Estimated OTTI Losses September 30, 2017 Cost Gains Losses Fair Value (Gains) (In millions) Fixed maturity securities: Corporate and other bonds $ 17,965 $ 1,645 $ 26 $ 19,584 States, municipalities and political subdivisions 12,462 1,501 7 13,956 $ (14 ) Asset-backed: Residential mortgage-backed 4,906 127 28 5,005 (28 ) Commercial mortgage-backed 1,858 55 13 1,900 Other asset-backed 1,047 18 4 1,061 Total asset-backed 7,811 200 45 7,966 (28 ) U.S. Treasury and obligations of government-sponsored enterprises 115 3 3 115 Foreign government 439 10 4 445 Redeemable preferred stock 18 2 20 Fixed maturities available-for-sale 38,810 3,361 85 42,086 (42 ) Fixed maturities trading 420 2 1 421 Total fixed maturities 39,230 3,363 86 42,507 (42 ) Equity securities: Common stock 16 7 1 22 Preferred stock 102 5 107 Equity securities available-for-sale 118 12 1 129 - Equity securities trading 474 86 79 481 Total equity securities 592 98 80 610 - Total $ 39,822 $ 3,461 $ 166 $ 43,117 $ (42 ) December 31, 2016 Fixed maturity securities: Corporate and other bonds $ 17,711 $ 1,323 $ 76 $ 18,958 $ (1 ) States, municipalities and political subdivisions 12,060 1,213 33 13,240 (16 ) Asset-backed: Residential mortgage-backed 5,004 120 51 5,073 (28 ) Commercial mortgage-backed 2,016 48 24 2,040 Other asset-backed 1,022 8 5 1,025 Total asset-backed 8,042 176 80 8,138 (28 ) U.S. Treasury and obligations of government-sponsored enterprises 83 10 93 Foreign government 435 13 3 445 Redeemable preferred stock 18 1 19 Fixed maturities available-for-sale 38,349 2,736 192 40,893 (45 ) Fixed maturities trading 598 3 601 Total fixed maturities 38,947 2,739 192 41,494 (45 ) Equity securities: Common stock 13 6 19 Preferred stock 93 2 4 91 Equity securities available-for-sale 106 8 4 110 - Equity securities trading 465 60 86 439 Total equity securities 571 68 90 549 - Total $ 39,518 $ 2,807 $ 282 $ 42,043 $ (45 ) 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 noncontrolling interests and any required Shadow Adjustments. To the extent that unrealized gains on fixed income securities supporting certain long term care products would result in a premium deficiency if realized, a related increase in Insurance reserves is recorded, net of tax and noncontrolling interests, as a reduction of net unrealized gains through Other comprehensive income (“Shadow Adjustments”). As of September 30, 2017 and December 31, 2016, the net unrealized gains on investments included in AOCI were correspondingly reduced by Shadow Adjustments of $1.2 billion and $909 million (after tax and noncontrolling interests). The available-for-sale Less than 12 Months 12 Months or Longer Total September 30, 2017 Estimated Gross Estimated Gross Estimated Gross (In millions) Fixed maturity securities: Corporate and other bonds $ 1,216 $ 21 $ 91 $ 5 $ 1,307 $ 26 States, municipalities and political subdivisions 583 6 56 1 639 7 Asset-backed: Residential mortgage-backed 1,522 25 106 3 1,628 28 Commercial mortgage-backed 378 6 138 7 516 13 Other asset-backed 129 4 10 139 4 Total asset-backed 2,029 35 254 10 2,283 45 U.S. Treasury and obligations of government-sponsored enterprises 67 3 6 73 3 Foreign government 191 4 5 196 4 Total fixed maturity securities 4,086 69 412 16 4,498 85 Equity securities: Common stock 2 1 2 1 Preferred stock 16 16 - Total equity securities 18 1 - - 18 1 Total $ 4,104 $ 70 $ 412 $ 16 $ 4,516 $ 86 December 31, 2016 Fixed maturity securities: Corporate and other bonds $ 2,615 $ 61 $ 254 $ 15 $ 2,869 $ 76 States, municipalities and political subdivisions 959 32 23 1 982 33 Asset-backed: Residential mortgage-backed 2,136 44 201 7 2,337 51 Commercial mortgage-backed 756 22 69 2 825 24 Other asset-backed 398 5 24 422 5 Total asset-backed 3,290 71 294 9 3,584 80 U.S. Treasury and obligations of government-sponsored enterprises 5 5 - Foreign government 108 3 108 3 Total fixed maturity securities 6,977 167 571 25 7,548 192 Equity securities 12 13 4 25 4 Total $ 6,989 $ 167 $ 584 $ 29 $ 7,573 $ 196 Based on current facts and circumstances, the Company believes the unrealized losses presented in the September 30, 2017 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, 2017. 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, 2017 and 2016 for which a portion of an OTTI loss was recognized in Other comprehensive income. Three Months Ended Nine Months Ended September 30, September 30, 2017 2016 2017 2016 (In millions) Beginning balance of credit losses on fixed maturity securities $ 30 $ 41 $ 36 $ 53 Reductions for securities sold during the period (2 ) (2 ) (8 ) (14 ) Reductions for securities the Company intends to sell or more likely than not will be required to sell (1 ) (1 ) Ending balance of credit losses on fixed maturity securities $ 28 $ 38 $ 28 $ 38 Contractual Maturity The following table presents available-for-sale September 30, 2017 December 31, 2016 Cost or Estimated Cost or Estimated (In millions) Due in one year or less $ 1,374 $ 1,404 $ 1,779 $ 1,828 Due after one year through five years 7,931 8,293 7,566 7,955 Due after five years through ten years 15,853 16,574 15,892 16,332 Due after ten years 13,652 15,815 13,112 14,778 Total $ 38,810 $ 42,086 $ 38,349 $ 40,893 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 A summary of the aggregate contractual or notional amounts and gross estimated fair values related to derivative financial instruments follows. The contractual or notional amounts for derivatives are used to calculate the exchange of contractual payments under the agreements and may not be representative of the potential for gain or loss on these instruments. Gross estimated fair values of derivative positions are currently presented in Equity securities, Receivables and Payable to brokers on the Consolidated Condensed Balance Sheets. September 30, 2017 December 31, 2016 Contractual/ Contractual/ Notional Estimated Fair Value Notional Estimated Fair Value Amount Asset (Liability) Amount Asset (Liability) (In millions) With hedge designation: Interest rate swaps $ 500 Without hedge designation: Equity markets: Options – purchased 267 $ 15 $ 223 $ 14 – written 296 $ (8 ) 267 $ (8 ) Futures – short 249 (1 ) 225 1 Commodity futures – long 39 42 Embedded derivative on funds withheld liability 170 (1 ) 174 3

Fair Value

Fair Value	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Fair Value	4. 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) detailed analysis, 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 on a recurring basis are presented in the following tables: September 30, 2017 Level 1 Level 2 Level 3 Total (In millions) Fixed maturity securities: Corporate and other bonds $ 19,465 $ 119 $ 19,584 States, municipalities and political subdivisions 13,955 1 13,956 Asset-backed: Residential mortgage-backed 4,829 176 5,005 Commercial mortgage-backed 1,876 24 1,900 Other asset-backed 915 146 1,061 Total asset-backed 7,620 346 7,966 U.S. Treasury and obligations of government-sponsored enterprises $ 115 115 Foreign government 445 445 Redeemable preferred stock 20 20 Fixed maturities available-for-sale 135 41,485 466 42,086 Fixed maturities trading 9 407 5 421 Total fixed maturities $ 144 $ 41,892 $ 471 $ 42,507 Equity securities available-for-sale $ 110 $ 19 $ 129 Equity securities trading 479 2 481 Total equity securities $ 589 $ - $ 21 $ 610 Short term investments $ 4,019 $ 876 $ 4,895 Other invested assets 61 5 66 Payable to brokers (9 ) (9 ) December 31, 2016 Level 1 Level 2 Level 3 Total (In millions) Fixed maturity securities: Corporate and other bonds $ 18,828 $ 130 $ 18,958 States, municipalities and political subdivisions 13,239 1 13,240 Asset-backed: Residential mortgage-backed 4,944 129 5,073 Commercial mortgage-backed 2,027 13 2,040 Other asset-backed 968 57 1,025 Total asset-backed 7,939 199 8,138 U.S. Treasury and obligations of government-sponsored enterprises $ 93 93 Foreign government 445 445 Redeemable preferred stock 19 19 Fixed maturities available-for-sale 112 40,451 330 40,893 Fixed maturities trading 595 6 601 Total fixed maturities $ 112 $ 41,046 $ 336 $ 41,494 Equity securities available-for-sale $ 91 $ 19 $ 110 Equity securities trading 438 1 439 Total equity securities $ 529 $ - $ 20 $ 549 Short term investments $ 3,833 $ 853 $ 4,686 Other invested assets 55 5 60 Receivables 1 1 Life settlement contracts $ 58 58 Payable to brokers (44 ) (44 ) The following tables present reconciliations for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the three and nine months ended September 30, 2017 and 2016: Net Realized Gains Unrealized (Losses) 2017 Balance, Included in Included in Purchases Sales Settlements Transfers Transfers Balance, Liabilities (In millions) Fixed maturity securities: Corporate and other bonds $ 100 $ 1 $ 1 $ 13 $ (11 ) $ 15 $ 119 States, municipalities and political subdivisions 1 1 Asset-backed: Residential mortgage-backed 123 1 1 (7 ) 58 176 Commercial mortgage-backed 13 (1 ) 12 (2 ) 2 24 Other asset-backed 82 (1 ) 1 27 (4 ) 41 146 Total asset-backed 218 - 1 39 $ - (13 ) 101 $ - 346 $ - Fixed maturities available-for-sale 319 1 2 52 (24 ) 116 466 Fixed maturities trading 5 5 Total fixed maturities $ 324 $ 1 $ 2 $ 52 $ - $ (24 ) $ 116 $ - $ 471 $ - Equity securities available-for-sale $ 19 $ 19 Equity securities trading 1 $ 1 2 Total equity securities $ 20 $ - $ - $ 1 $ - $ - $ - $ - $ 21 $ - Life settlement contracts $ 1 $ (1) $ - Net Realized Gains Transfers Transfers Unrealized (Losses) 3 Assets and Liabilities 2016 Balance, Included in Included in Purchases Sales Settlements into out of Balance, Held at (In millions) Fixed maturity securities: Corporate and other bonds $ 242 $ 1 $ 7 $ 16 $ (5 ) $ 261 States, municipalities and political subdivisions 2 (1 ) 1 Asset-backed: Residential mortgage-backed 134 (1 ) 5 (1 ) $ (58 ) 79 Commercial mortgage-backed 11 23 (8 ) (2 ) 24 Other asset-backed 45 34 (36 ) 43 Total asset-backed 190 - (1 ) 62 $ - (9 ) $ - (96 ) 146 $ - Fixed maturities available-for-sale 434 1 6 78 (15 ) (96 ) 408 Fixed maturities trading 6 6 (1 ) Total fixed maturities $ 440 $ 1 $ 6 $ 78 $ - $ (15 ) $ - $ (96 ) $ 414 $ (1 ) Equity securities available-for-sale $ 19 $ (1 ) $ 1 $ 19 $ (2 ) Equity securities trading 2 $ (1 ) 1 (1 ) Total equity securities $ 21 $ (1 ) $ 1 $ (1 ) $ - $ - $ - $ - $ 20 $ (3 ) Life settlement contracts $ 67 $ 67 Derivative financial instruments, net 1 $ (1 ) - Net Realized Gains Unrealized (Losses) 2017 Balance, January 1 Included in Included in Purchases Sales Settlements Transfers Transfers Balance, Liabilities (In millions) Fixed maturity securities: Corporate and other bonds $ 130 $ 1 $ 2 $ 18 $ (1) $ (36 ) $ 15 $ (10 ) $ 119 States, municipalities and political subdivisions 1 1 Asset-backed: Residential mortgage-backed 129 3 4 (18 ) 58 176 Commercial mortgage-backed 13 (1 ) 12 (2 ) 2 24 Other asset-backed 57 (2 ) 1 78 (6 ) 93 (75 ) 146 Total asset-backed 199 1 4 90 - (26 ) 153 (75 ) 346 $ - Fixed maturities available-for-sale 330 2 6 108 (1) (62 ) 168 (85 ) 466 Fixed maturities trading 6 (1 ) 5 (1 ) Total fixed maturities $ 336 $ 1 $ 6 $ 108 $ (1) $ (62 ) $ 168 $ (85 ) $ 471 $ (1 ) Equity securities available-for-sale $ 19 $ 2 $ 1 $ (3) $ 19 Equity securities trading 1 1 2 Total equity securities $ 20 $ - $ 2 $ 2 $ (3) $ - $ - $ - $ 21 $ - Life settlement contracts $ 58 $ 6 $ (59) $ (5 ) $ - Derivative financial instruments, net - 1 (1) - Net Realized Gains Transfers Transfers Unrealized (Losses) 3 Assets and 2016 Balance, January 1 Included in Included in Purchases Sales Settlements into out of Balance, Held at (In millions) Fixed maturity securities: Corporate and other bonds $ 168 $ 1 $ 14 $ 163 $ (36 ) $ (15 ) $ (34 ) $ 261 States, municipalities and political subdivisions 2 (1 ) 1 Asset-backed: Residential mortgage-backed 134 2 (2 ) 15 (10 ) (60 ) 79 Commercial mortgage-backed 22 32 (17 ) $ 3 (16 ) 24 Other asset-backed 53 2 69 (25 ) (1 ) 2 (57 ) 43 Total asset-backed 209 2 - 116 (25 ) (28 ) 5 (133 ) 146 $ - Fixed maturities available-for-sale 379 3 14 279 (61 ) (44 ) 5 (167 ) 408 Fixed maturities trading 85 5 2 (86 ) 6 3 Total fixed maturities $ 464 $ 8 $ 14 $ 281 $ (147 ) $ (44 ) $ 5 $ (167 ) $ 414 $ 3 Equity securities available-for-sale $ 20 $ (1 ) $ 19 $ (2 ) Equity securities trading 1 1 $ (1 ) 1 Total equity securities $ 21 $ - $ - $ - $ (1 ) $ - $ - $ - $ 20 $ (2 ) Life settlement contracts $ 74 $ 10 $ (17 ) $ 67 $ 2 Derivative financial instruments, net 3 (4 ) $ (2 ) $ 3 - (3 ) Net realized and unrealized gains and losses are reported in Net income (loss) as follows: Major Category of Assets and Liabilities Consolidated Condensed Statements of Income Line Items Fixed maturity securities available-for-sale Investment gains (losses) Fixed maturity securities trading Net investment income Equity securities available-for-sale Investment gains (losses) Equity securities trading Net investment income Other invested assets Investment gains (losses) and Net investment income Derivative financial instruments held in a trading portfolio Net investment income Derivative financial instruments, other Investment gains (losses) and Other revenues Life settlement contracts Other revenues 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. During the three and nine months ended September 30, 2017 and 2016 there were no transfers between Level 1 and Level 2. The Company’s policy is to recognize transfers between levels at the beginning of quarterly reporting periods. 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 and redeemable preferred stock, 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 non-redeemable Derivative Financial Instruments Exchange traded derivatives are valued using quoted market prices and are classified within Level 1 of the fair value hierarchy. Level 2 derivatives primarily include currency forwards valued using observable market forward rates. Over-the-counter Short Term Investments 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 in the Consolidated Condensed Balance Sheets because certain short term investments, such as time deposits, are not measured at fair value. Other Invested Assets Level 1 securities include exchange traded open-end Life Settlement Contracts CNA accounts for its investment in life settlement contracts using the fair value method. Historically, the fair value of life settlement contracts was determined as the present value of the anticipated death benefits less anticipated premium payments based on contract terms that are distinct for each insured, as well as CNA’s own assumptions for mortality, premium expense and the rate of return that a buyer would require on the contracts. The entire portfolio of life settlement contracts was determined to be held for sale as of December 31, 2016 as CNA reached an agreement on terms to sell the portfolio. As such, CNA adjusted the fair value to the estimated sales proceeds less cost to sell. The definitive Purchase and Sale Agreement (“PSA”) related to the portfolio was executed on March 7, 2017 (“sale date”). In connection therewith, the life settlement contracts and related sale proceeds were placed in escrow until the buyer was recognized as the owner and beneficiary of each individual life settlement contract by the life insurance company that issued the policy. All of the contracts have been released from escrow as of September 30, 2017. CNA derecognized the released contracts and recorded the consideration, including a note receivable, which is payable over three years and is carried at amortized cost less any valuation allowance. The note receivable of $45 million is included within Other assets on the September 30, 2017 Consolidated Condensed Balance Sheet and interest income is accreted to the principal balance of the note. The fair value of CNA’s investments in life settlement contracts were $0 million and $58 million as of September 30, 2017 and December 31, 2016, and are included in Other assets on the Consolidated Condensed Balance Sheets. Despite the sale, the contracts were classified as Level 3 as there is not an active market for life settlement contracts. The cash receipts and payments related to the life settlement contracts prior to the sale date are included in operating activities on the Consolidated Condensed Statements of Cash Flows. Cash receipts related to the sale of the life settlement contracts as well as principal payments on the note receivable are included in investing activities. Significant Unobservable Inputs The following tables present quantitative information about the significant unobservable inputs utilized by the Company in the fair value measurement 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 unobservable inputs from these broker quotes is neither provided nor reasonably available to the Company. The valuation of life settlement contracts was based on the terms of the sale of the contracts to a third party; therefore the contracts are not included in the tables below. September 30, 2017 Estimated Fair Value Valuation Techniques Unobservable Inputs Range (Weighted Average) (In millions) Fixed maturity securities $ 139 Discounted cash flow Credit spread 1% – 12% (3%) December 31, 2016 Fixed maturity securities $ 106 Discounted cash flow Credit spread 2% – 40% (4%) 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, estimated fair value and the level of the fair value hierarchy of the Company’s financial assets and liabilities which are not measured at fair value on the Consolidated Condensed Balance Sheets are presented in the following tables. The carrying amounts and estimated fair values of short term debt and long term debt exclude capital lease obligations. The carrying amounts reported on the Consolidated Condensed Balance Sheets for cash and short term investments not carried at fair value and certain other assets and liabilities approximate fair value due to the short term nature of these items. Carrying Estimated Fair Value September 30, 2017 Amount Level 1 Level 2 Level 3 Total (In millions) Assets: Other invested assets, primarily mortgage loans $ 722 $ 731 $ 731 Liabilities: Short term debt 191 $ 152 41 193 Long term debt 11,222 10,316 1,216 11,532 December 31, 2016 Assets: Other invested assets, primarily mortgage loans $ 591 $ 594 $ 594 Liabilities: Short term debt 107 $ 104 3 107 Long term debt 10,655 10,150 646 10,796 The following methods and assumptions were used in estimating the fair value of these financial assets and liabilities. The fair values of mortgage loans, included in Other invested assets, were based on the present value of the expected future cash flows discounted at the current interest rate for similar financial instruments, adjusted for specific loan risk. Fair value of debt was based on observable market prices when available. When observable market prices were not available, the fair value of debt was based on observable market prices of comparable instruments adjusted for differences between the observed instruments and the instruments being valued or is estimated using discounted cash flow analyses, based on current incremental borrowing rates for similar types of borrowing arrangements.

Property, Plant and Equipment

Property, Plant and Equipment	9 Months Ended
	Sep. 30, 2017
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	5. Property, Plant and Equipment Diamond Offshore Asset Impairments During the third quarter of 2017, Diamond Offshore evaluated six drilling rigs with indicators of impairment. Based on its assumptions and analyses, Diamond Offshore determined that the carrying values of these rigs were not impaired. If market fundamentals in the offshore oil and gas industry deteriorate further or a market recovery is delayed, additional impairment losses may be required to be recognized in future periods. During the second quarter of 2017, Diamond Offshore evaluated seven drilling rigs with indicators of impairment. Due to the continued deterioration of market fundamentals in the contract drilling industry, as well as newly-available market projections, which indicated that a full market recovery is likely to occur further in the future than had previously been estimated, Diamond Offshore determined that the carrying values of one ultra-deepwater and one deepwater semisubmersible rig were impaired. Diamond Offshore estimated the fair value of the rigs impaired in 2017 using an income approach, whereby the fair value of each rig was estimated based on a calculation of the rig’s future net cash flows. These calculations utilized significant unobservable inputs, including estimated proceeds that may be received on ultimate disposition of the rig, and are representative of Level 3 fair value measurements due to the significant level of estimation involved and lack of transparency as to the inputs used. During the second quarter of 2017, Diamond Offshore recorded an asset impairment charge of $72 million ($23 million after tax and noncontrolling interests), which is included in Other operating expenses on the Consolidated Condensed Statements of Income. Diamond Offshore recorded aggregate asset impairment charges of $672 million ($263 million after tax and noncontrolling interests), which is included in Other operating expenses on the Consolidated Condensed Statements of Income for the nine months ended September 30, 2016. See Note 6 of the Consolidated Financial Statements in the Company’s Annual Report on Form 10-K Boardwalk Pipeline Sale of Assets In May of 2017, Boardwalk Pipeline sold a processing plant and related assets, for approximately $64 million, including customary adjustments. The sale resulted in a loss of $47 million ($15 million after tax and noncontrolling interests) and is included in Other operating expenses on the Consolidated Condensed Statements of Income.

Claim and Claim Adjustment Expe

Claim and Claim Adjustment Expense Reserves	9 Months Ended
	Sep. 30, 2017
Insurance [Abstract]
Claim and Claim Adjustment Expense Reserves	6. Claim and Claim Adjustment Expense Reserves CNA’s 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. CNA’s reserve projections are based primarily on detailed analysis of the facts in each case, CNA’s experience with similar cases and various historical development patterns. Consideration is given to such historical patterns as claim reserving trends and settlement practices, loss payments, pending levels of unpaid claims and product mix, as well as court decisions, 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 all 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 CNA’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 Liability for Unpaid Claim and Claim Adjustment Expenses Rollforward The following table presents a reconciliation between beginning and ending claim and claim adjustment expense reserves, including claim and claim adjustment expense reserves of non-core Nine Months Ended September 30 2017 2016 (In millions) Reserves, beginning of year: Gross $ 22,343 $ 22,663 Ceded 4,094 4,087 Net reserves, beginning of year 18,249 18,576 Net incurred claim and claim adjustment expenses: Provision for insured events of current year 3,949 3,799 Decrease in provision for insured events of prior years (284 ) (332 ) Amortization of discount 138 134 Total net incurred (a) 3,803 3,601 Net payments attributable to: Current year events (560 ) (591 ) Prior year events (3,401 ) (3,209 ) Total net payments (3,961 ) (3,800 ) Foreign currency translation adjustment and other 110 39 Net reserves, end of period 18,201 18,416 Ceded reserves, end of period 4,008 4,256 Gross reserves, end of period $ 22,209 $ 22,672 (a) Total net incurred above does not agree to Insurance claims and policyholders’ benefits as reflected in the Consolidated Condensed Statements of Income 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 allocated claim adjustment expense reserves and premium accruals, net of reinsurance, for prior years are defined as net prior year development. These changes can be favorable or unfavorable. The following table and discussion present net prior year development: Three Months Ended Nine Months Ended 2017 2016 2017 2016 (In millions) Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development $ (115 ) $ (132 ) $ (227 ) $ (282 ) Pretax (favorable) unfavorable premium development (19 ) (5 ) (2 ) (27 ) Total pretax (favorable) unfavorable net prior year development $ (134 ) $ (137 ) $ (229 ) $ (309 ) Premium development can occur in the property and casualty business when there is a change in exposure on auditable policies or when premium accruals differ from processed premium. Audits on policies usually occur in a period after the expiration date of the policy. See Note 11 for further information on the premium development for the Small Business multi-peril package product and workers’ compensation policies for the three and nine months ended September 30, 2017. The following table and discussion present details of the net prior year claim and allocated claim adjustment expense reserve development (“development”): Three Months Ended Nine Months Ended 2017 2016 2017 2016 (In millions) Medical professional liability $ 1 $ 13 $ 5 $ (17 ) Other professional liability and management liability (27 ) (48 ) (96 ) (98 ) Surety (82 ) (63 ) (82 ) (63 ) Commercial auto (14 ) (12 ) (40 ) (47 ) General liability 7 14 6 (38 ) Workers’ compensation 7 (6 ) (39 ) 48 Other (7 ) (30 ) 19 (67 ) Total pretax (favorable) unfavorable development $ (115 ) $ (132 ) $ (227 ) $ (282 ) Three Months 2017 Favorable development in other professional and management liability was primarily due to lower than expected claim frequency in accident years 2012 through 2015, primarily for professional liability products. Favorable development in surety coverages was primarily due to lower than expected frequency of large losses in accident years 2015 and prior. Favorable development for commercial auto was primarily due to lower than expected severity in accident years 2015 and 2016, as well as a large favorable recovery on a claim in accident year 2012. Unfavorable development in workers’ compensation reflects the recognition of loss estimates related to favorable premium development as well as an adverse arbitration ruling related to reinsurance recoverables from older accident years. Favorable development for other coverages reflects better than expected emergence in Canadian run-off 2016 Unfavorable development for medical professional liability was primarily due to higher than expected frequency in accident years 2014 and 2015 in aging services. Increased claims on a specific hospital policy in accident years 2014 and 2015 was also an unfavorable contributor, although more than offset by favorable development relative to expectations in accident years 2013 and prior. Favorable development in other professional liability and management liability was primarily related to lower than expected frequency of claims and favorable outcomes on specific claims for accident years 2010 through 2014. Favorable development in surety coverages was primarily due to lower than expected frequency of large losses in accident years 2014 and prior. Favorable development for commercial auto was primarily due to lower than expected severities in accident years 2012 through 2015. Unfavorable development for general liability was primarily due to an increase in reported claims prior to the closing of the three year window set forth by the Minnesota Child Victims Act in accident years 2006 and prior. Favorable development for workers’ compensation was primarily driven by lower than expected frequencies in accident years 2009 through 2014, partially offset by the estimated impact of recent Florida court rulings in accident years 2008 through 2015. Favorable development for other coverages was primarily due to better than expected claim frequency in commercial lines coverages provided to customers in accident years 2010 through 2015, favorable settlements on claims in accident years 2013 and prior and favorable emergence of expected losses on a specific claim relating to the December 2015 United Kingdom (“U.K.”) floods for property and marine. This favorable development was partially offset by higher than expected unfavorable large loss emergence in accident years 2014 and 2015. Nine Months 2017 Favorable development in other professional liability and management liability was primarily due to favorable settlements on closed claims and a lower frequency of large losses for accident years 2011 through 2016 for professional and management liability, lower than expected claim frequency in accident years 2012 through 2015 for professional liability and lower than expected severity in accident years 2014 through 2016 for professional liability. Favorable development in surety coverages was primarily due to lower than expected frequency of large losses in accident years 2015 and prior. Favorable development for commercial auto was primarily due to lower than expected severity in accident years 2013 through 2016, as well as a large favorable recovery on a claim in accident year 2012. Favorable development for workers’ compensation was primarily related to decreases in frequency and severity in recent accident years, partially attributable to California reforms related to decreases in medical costs. This was partially offset by unfavorable development related to an adverse arbitration ruling on reinsurance recoverables from older accident years as well as the recognition of loss estimates associated with favorable premium development. Favorable development for other coverages was primarily due to better than expected emergence in the Canadian run-off 2016 Favorable development for medical professional liability was primarily due to lower than expected severities for individual healthcare professionals, allied facilities and hospitals in accident years 2011 and prior. This was partially offset by unfavorable development in accident years 2012 and 2013 related to higher than expected large loss emergence in hospitals and higher than expected frequency and severity in accident years 2014 and 2015 in CNA’s aging services business. Favorable development in other professional liability and management liability was primarily related to favorable settlements on closed claims in accident years 2011 through 2013 in professional services. Additional favorable development related to lower than expected frequency of claims and favorable outcomes on specific claims in accident years 2010 through 2014 in professional services. This was partially offset by unfavorable development related to a specific financial institutions claim in accident year 2014, higher severities in accident year 2015 and deterioration on credit crises-related claims in accident year 2009. Favorable development in surety coverages was primarily due to lower than expected frequency of large losses in accident years 2014 and prior. Favorable development for commercial auto was primarily due to favorable settlements on claims in accident years 2010 through 2014 and lower than expected severities in accident years 2012 through 2015. Favorable development for general liability was primarily due to better than expected claim settlements in accident years 2012 through 2014 and better than expected severity on umbrella claims in accident years 2010 through 2013. This was partially offset by unfavorable development related to an increase in reported claims prior to the closing of the three year window set forth by the Minnesota Child Victims Act in accident years 2006 and prior. Unfavorable development for workers’ compensation was primarily due to higher than expected severity for Defense Base Act contractors and the estimated impact of recent Florida court rulings in accident years 2008 through 2015. This was partially offset by favorable development related to lower than expected frequencies related to accident years 2009 through 2014. Favorable development for other coverages was primarily due to better than expected claim frequency in property coverages in accident year 2015 and commercial lines coverages in accident years 2010 through 2015, better than expected loss frequency in accident years 2013 through 2015 for property and other, favorable settlements on claims in accident years 2013 and prior, better than expected severity in accident years 2013 and prior for liability, favorable emergence of expected losses on a specific claim relating to the December 2015 U.K. floods for property and marine and better than expected severity in accident years 2011 through 2015 for auto liability. This favorable development was partially offset by higher than expected severity from a 2015 catastrophe event for property and other and higher than expected large loss emergence in accident years 2011 through 2015. Asbestos and Environmental Pollution (“A&EP”) Reserves In 2010, Continental Casualty Company (“CCC”) together with several of CNA’s insurance subsidiaries completed a transaction with National Indemnity Company (“NICO”), a subsidiary of Berkshire Hathaway Inc., under which substantially all of CNA’s legacy A&EP liabilities were ceded to NICO through a loss portfolio transfer (“LPT”). At the effective date of the transaction, CNA 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 $4.0 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. CNA paid NICO a reinsurance premium of $2.0 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. Subsequent to the effective date of the LPT, CNA recognized adverse prior year development on its A&EP reserves which resulted in additional amounts ceded under the LPT. As a result, the cumulative amounts ceded under the LPT 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 CNA recognizes a change in the estimate of A&EP reserves that increases the amounts ceded under the LPT, the proportion of actual paid recoveries to total ceded losses is impacted 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 in the Consolidated Condensed Statements of Income. The following table presents the impact of the loss portfolio transfer on the Consolidated Condensed Statements of Income. Three Months Ended Nine Months Ended 2017 2016 2017 2016 (In millions) Net A&EP adverse development before consideration of LPT $ - $ - $ 60 $ 200 Retroactive reinsurance benefit recognized (17 ) (12 ) (60 ) (94 ) Pretax impact of A&EP reserve development and the LPT $ (17 ) $ (12 ) $ - $ 106 Based upon CNA’s annual A&EP reserve review, net unfavorable prior year development of $60 million and $200 million was recognized before consideration of cessions to the LPT for the nine months ended September 30, 2017 and 2016. The 2017 unfavorable development was driven by modestly higher anticipated payouts on claims from known sources of asbestos exposure. The 2016 unfavorable development was driven by an increase in anticipated future expenses associated with determination of coverage, higher anticipated payouts associated with a limited number of historical accounts having significant asbestos exposures and higher than expected severity on pollution claims. While this unfavorable development was ceded to NICO under the LPT, CNA’s reported earnings in both periods were negatively affected due to the application of retroactive reinsurance accounting. As of September 30, 2017 and December 31, 2016, the cumulative amounts ceded under the LPT were $2.9 billion and $2.8 billion. The unrecognized deferred retroactive reinsurance benefit was $334 million as of September 30, 2017 and December 31, 2016. NICO established a collateral trust account as security for its obligations to CNA. The fair value of the collateral trust account was $2.9 billion and $2.8 billion as of September 30, 2017 and December 31, 2016. 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 CNA’s A&EP claims.

Debt

Debt	9 Months Ended
	Sep. 30, 2017
Debt Disclosure [Abstract]
Debt	7. Debt CNA Financial In the third quarter of 2017, CNA completed a public offering of $500 million aggregate principal amount of its 3.5% senior notes due August 15, 2027 and used a portion of the net proceeds to redeem the entire $350 million outstanding principal amount of its 7.4% senior notes due November 15, 2019. The redemption of the $350 million senior notes resulted in a loss of $42 million ($24 million after tax and noncontrolling interests) and is included in Interest expense on the Consolidated Condensed Statements of Income for the three and nine months ended September 30, 2017. Diamond Offshore In the third quarter of 2017, Diamond Offshore completed a public offering of $500 million aggregate principal amount of its 7.9% senior notes due August 15, 2025 and used the net proceeds together with cash on hand to redeem the entire $500 million outstanding principal amount of its 5.9% senior notes due May 1, 2019. The redemption of this debt resulted in a loss of $35 million ($11 million after tax and noncontrolling interests) and is included in Interest expense on the Consolidated Condensed Statements of Income for the three and nine months ended September 30, 2017. Boardwalk Pipeline In the first quarter of 2017, Boardwalk Pipeline completed a public offering of $500 million aggregate principal amount of its 4.5% senior notes due July 15, 2027 and used the net proceeds to repay the entire $275 million outstanding principal amount of its 6.3% senior notes due August 15, 2017 and to fund growth capital expenditures. Consolidated Container In the second quarter of 2017, Consolidated Container entered into a credit agreement providing for a $605 million term loan and a five year $125 million asset based lending facility (“ABL facility”) in conjunction with the acquisition discussed in Note 2. The term loan is a variable rate facility which bears interest at a floating rate equal to the London Interbank Offered Rate (“LIBOR”) plus an applicable margin of 3.5%, subject to a 1.0% floor. The term loan matures on May 22, 2024 and requires annual principal amortization of 1.0% of the original loan amount beginning December 31, 2017. Consolidated Container recorded approximately $19 million of debt issuance costs, which will be amortized over the terms of the facilities. Consolidated Container entered into interest rate swaps for a notional amount of $500 million to hedge its cash flow exposure to the variable rate debt. These swaps effectively fix the interest rate on the hedged portion of the term loan at approximately 5.6%. As of September 30, 2017, Consolidated Container had no borrowings outstanding under its ABL facility.

Shareholders' Equity

Shareholders' Equity	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Shareholders' Equity	8. Shareholders’ Equity Accumulated other comprehensive income (loss) The tables below present the changes in AOCI by component for the three and nine months ended September 30, 2016 and 2017: OTTI Unrealized on Investments Cash Flow Pension Foreign Total (In millions) Balance, July 1, 2016 $ 28 $ 838 $ (2 ) $ (639 ) $ (106 ) $ 119 Other comprehensive income (loss) before reclassifications, after tax of $(4), $(32), $0, $0 and $0 7 69 (24 ) 52 Reclassification of (gains) losses from accumulated other comprehensive income, after tax of $2, $13, $0, $(4) and $0 (4 ) (27 ) 1 7 (23 ) Other comprehensive income (loss) 3 42 1 7 (24 ) 29 Amounts attributable to noncontrolling interests (1 ) (4 ) (1 ) 2 (4 ) Balance, September 30, 2016 $ 30 $ 876 $ (2 ) $ (632 ) $ (128 ) $ 144 Balance, July 1, 2017 $ 23 $ 705 $ (2 ) $ (632 ) $ (130 ) $ (36 ) Other comprehensive income (loss) before reclassifications, after tax of $0, $(20), $0, $0 and $0 1 35 (2 ) 41 75 Reclassification of (gains) losses from accumulated other comprehensive income, after tax of $0, $4, $0, $(6) and $0 (12 ) 3 11 2 Other comprehensive income 1 23 1 11 41 77 Amounts attributable to noncontrolling interests (3 ) (1 ) (1 ) (4 ) (9 ) Balance, September 30, 2017 $ 24 $ 725 $ (2 ) $ (622 ) $ (93 ) $ 32 OTTI Unrealized Cash Flow Pension Foreign Total (In millions) Balance, January 1, 2016 $ 24 $ 347 $ (3 ) $ (649 ) $ (76 ) $ (357 ) Other comprehensive income (loss) before reclassifications, after tax of $(5), $(304), $0, $0 and $0 9 608 (58 ) 559 Reclassification of (gains) losses from accumulated other comprehensive income, after tax of $1, $12, $0, $(11) and $0 (2 ) (17 ) 2 20 3 Other comprehensive income (loss) 7 591 2 20 (58 ) 562 Amounts attributable to noncontrolling interests (1 ) (62 ) (1 ) (3 ) 6 (61 ) Balance, September 30, 2016 $ 30 $ 876 $ (2 ) $ (632 ) $ (128 ) $ 144 Balance, January 1, 2017 $ 27 $ 576 $ (2 ) $ (646 ) $ (178 ) $ (223 ) Other comprehensive income (loss) before reclassifications, after tax of $0, $(130), $0, $0 and $0 228 (3 ) 94 319 Reclassification of (gains) losses from accumulated other comprehensive income, after tax of $1, $28, $0, $(13) and $0 (3 ) (61 ) 4 26 (34 ) Other comprehensive income (loss) (3 ) 167 1 26 94 285 Amounts attributable to noncontrolling interests (18 ) (1 ) (2 ) (9 ) (30 ) Balance, September 30, 2017 $ 24 $ 725 $ (2 ) $ (622 ) $ (93 ) $ 32 Amounts reclassified from AOCI shown above are reported in Net income as follows: Major Category of AOCI Affected Line Item OTTI gains (losses) Investment gains (losses) Unrealized gains (losses) on investments Investment gains (losses) Cash flow hedges Other revenues, Interest expense and Contract drilling expenses Pension liability Other operating expenses Treasury Stock The Company repurchased 0.1 million and 3.0 million shares of Loews common stock at aggregate costs of $6 million and $115 million during the nine months ended September 30, 2017 and 2016.

Benefit Plans

Benefit Plans	9 Months Ended
	Sep. 30, 2017
Retirement Benefits [Abstract]
Benefit Plans	9. Benefit Plans The Company has several non-contributory The following table presents the components of net periodic benefit cost for the plans: Pension Benefits Three Months Ended Nine Months Ended 2017 2016 2017 2016 (In millions) Service cost $ 2 $ 2 $ 6 $ 6 Interest cost 30 33 89 97 Expected return on plan assets (43 ) (45 ) (129 ) (133 ) Amortization of unrecognized net loss 10 11 32 34 Settlement charge 7 1 10 3 Net periodic benefit cost $ 6 $ 2 $ 8 $ 7 Other Postretirement Benefits Three Months Ended Nine Months Ended 2017 2016 2017 2016 (In millions) Service cost $ 1 $ 1 Interest cost $ 1 1 $ 2 2 Expected return on plan assets (1 ) (1 ) (3 ) (3 ) Amortization of unrecognized prior service benefit (1 ) (1 ) (2 ) (3 ) Net periodic benefit cost $ (1 ) $ - $ (3 ) $ (3 )

Legal Proceedings

Legal Proceedings	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Legal Proceedings	10. Legal Proceedings CNA Financial In September of 2016, a class action lawsuit was filed against CCC, Continental Assurance Company (“CAC”), CNA, the Investment Committee of the CNA 401(k) Plus Plan (“Plan”), The Northern Trust Company and John Does 1-10 Based on information currently available and CNA’s assessment of the mediation, CNA has recorded its best estimate of probable loss, however, it is reasonably possible that the ultimate liability may differ from that amount given the inherent uncertainty involved in this matter. After consideration of available insurance coverage, the Company does not believe that the ultimate resolution of this matter will have a material impact on its condensed consolidated financial statements; however, the timing of recognition of any additional loss, if any, and insurance recovery, if any, may differ. Other Litigation The Company and its subsidiaries are parties to other litigation arising in the ordinary course of business. The outcome of this litigation will not, in the opinion of management, materially affect the Company’s results of operations or equity.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	11. Commitments and Contingencies CNA Guarantees In the course of selling business entities and assets to third parties, CNA agreed to guarantee the performance of certain obligations of previously owned subsidiaries and to indemnify purchasers for losses arising out of breaches of representations and warranties with respect to the business entities or assets sold, including, in certain cases, losses arising from undisclosed liabilities or certain named litigation. Such guarantee and indemnification agreements in effect for sales of business entities, assets and third party loans may include provisions that survive indefinitely. As of September 30, 2017, the aggregate amount related to quantifiable guarantees was $375 million and the aggregate amount related to quantifiable indemnification agreements was $254 million. In certain cases, should CNA be required to make payments under any such guarantee, it would have the right to seek reimbursement from an affiliate of a previously owned subsidiary. In addition, CNA has agreed to provide indemnification to third party purchasers for certain losses associated with sold business entities or assets that are not limited by a contractual monetary amount. As of September 30, 2017, CNA had outstanding unlimited indemnifications in connection with the sales of certain of its business entities or assets 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. CNA 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, 2017, the potential amount of future payments CNA could be required to pay under these guarantees was approximately $1.8 billion, which will be paid over the lifetime of the annuitants. CNA does not believe any payment is likely under these guarantees, as CNA is the beneficiary of a trust that must be maintained at a level that approximates the discounted reserves for these annuities. CNA Small Business Premium Rate Adjustment In prior quarters, CNA identified rating errors related to its multi-peril package product and workers’ compensation policies within its Small Business unit and CNA determined that it would voluntarily issue premium refunds along with interest on affected policies. After the rating errors were identified, written and earned premium have been reported net of any impact from the premium rate adjustments. There was no premium development impact for the three months ended September 30, 2017 and $37 million of adverse premium development was recognized as a result of the rating errors for the nine months ended September 30, 2017. CNA’s pretax income was reduced by $1 million and $7 million for the three and nine months ended September 30, 2017 for interest due to policyholders on the premium rate adjustments. The policyholder refunds for the multi-package product were issued in the quarter ended September 30, 2017. The estimated refund liability for the workers’ compensation policies as of September 30, 2017 was $61 million including interest. Any fines or penalties related to the foregoing are reasonably possible, but are not expected to be material to the Company’s financial statements.

Segments

Segments	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Segments	12. Segments The Company has five reportable segments comprised of four individual operating subsidiaries, CNA, Diamond Offshore, Boardwalk Pipeline and Loews Hotels & Co; and the Corporate segment. Each of the operating subsidiaries are headed by a chief executive officer who is responsible for the operation of its business and has the duties and authority commensurate with that position. The operations of Consolidated Container since the acquisition date are included in the Corporate segment. For additional disclosures regarding the composition of the Company’s segments, see Note 20 of the Consolidated Financial Statements in the Company’s Annual Report on Form 10-K The following tables present the reportable segments of the Company and their contribution to the Consolidated Condensed Statements of Income. Amounts presented will not necessarily be the same as those in the individual financial statements of the Company’s subsidiaries due to adjustments for purchase accounting, income taxes and noncontrolling interests. Statements of Income by segment are presented in the following tables. Three Months Ended September 30, 2017 CNA Diamond Boardwalk Loews Corporate Total (In millions) Revenues: Insurance premiums $ 1,806 $ 1,806 Net investment income 509 $ 48 557 Investment gains 16 16 Contract drilling revenues $ 357 357 Other revenues 110 11 $ 301 $ 162 201 785 Total 2,441 368 301 162 249 3,521 Expenses: Insurance claims and policyholders’ benefits 1,480 1,480 Amortization of deferred acquisition costs 309 309 Contract drilling expenses 198 198 Other operating expenses 379 109 191 147 221 1,047 Interest 83 64 41 7 28 223 Total 2,251 371 232 154 249 3,257 Income (loss) before income tax 190 (3 ) 69 8 - 264 Income tax (expense) benefit (44 ) 14 (18 ) (4 ) (52) Net income 146 11 51 4 - 212 Amounts attributable to noncontrolling interests (16 ) (5 ) (34 ) (55) Net income attributable to Loews Corporation $ 130 $ 6 $ 17 $ 4 $ - $ 157 Three Months Ended September 30, 2016 CNA Financial Diamond Boardwalk Loews Corporate Total (In millions) Revenues: Insurance premiums $ 1,767 $ 1,767 Net investment income 524 $ 1 $ 36 561 Investment gains 45 45 Contract drilling revenues 340 340 Other revenues 97 9 $ 306 $ 161 1 574 Total 2,433 350 306 161 37 3,287 Expenses: Insurance claims and policyholders’ benefits 1,202 1,202 Amortization of deferred acquisition costs 314 314 Contract drilling expenses 187 187 Other operating expenses 402 108 212 151 25 898 Interest 39 19 48 6 18 130 Total 1,957 314 260 157 43 2,731 Income (loss) before income tax 476 36 46 4 (6 ) 556 Income tax (expense) benefit (132 ) (22 ) (9 ) (1 ) 1 (163) Net income (loss) 344 14 37 3 (5 ) 393 Amounts attributable to noncontrolling interests (36 ) (7 ) (23 ) (66) Net income (loss) attributable to Loews Corporation $ 308 $ 7 $ 14 $ 3 $ (5 ) $ 327 Nine Months Ended September 30, 2017 CNA Diamond Boardwalk Loews Corporate Total (In millions) Revenues: Insurance premiums $ 5,185 $ 5,185 Net investment income 1,529 $ 1 $ 109 1,639 Investment gains 93 93 Contract drilling revenues 1,113 1,113 Other revenues 329 30 $ 987 $ 510 294 2,150 Total 7,136 1,144 987 510 403 10,180 Expenses: Insurance claims and policyholders’ benefits 4,053 4,053 Amortization of deferred acquisition costs 926 926 Contract drilling expenses 598 598 Other operating expenses 1,086 414 646 443 389 2,978 Interest 166 119 131 20 68 504 Total 6,231 1,131 777 463 457 9,059 Income (loss) before income tax 905 13 210 47 (54 ) 1,121 Income tax (expense) benefit (226 ) 35 (46 ) (23 ) 20 (240) Net income (loss) 679 48 164 24 (34 ) 881 Amounts attributable to noncontrolling interests (71 ) (23 ) (104 ) (198) Net income (loss) attributable to Loews Corporation $ 608 $ 25 $ 60 $ 24 $ (34) $ 683 Nine Months Ended September 30, 2016 CNA Financial Diamond Boardwalk Loews Corporate Total (In millions) Revenues: Insurance premiums $ 5,196 $ 5,196 Net investment income 1,461 $ 1 $ 108 1,570 Investment gains (losses) 30 (12 ) 18 Contract drilling revenues 1,141 1,141 Other revenues 297 69 $ 961 $ 513 2 1,842 Total 6,984 1,199 961 513 110 9,767 Expenses: Insurance claims and policyholders’ benefits 3,949 3,949 Amortization of deferred acquisition costs 926 926 Contract drilling expenses 598 598 Other operating expenses 1,158 1,082 615 479 82 3,416 Interest 127 69 136 17 54 403 Total 6,160 1,749 751 496 136 9,292 Income (loss) before income tax 824 (550 ) 210 17 (26 ) 475 Income tax (expense) benefit (203 ) 78 (44 ) (10 ) 8 (171) Net income (loss) 621 (472 ) 166 7 (18 ) 304 Amounts attributable to noncontrolling interests (64 ) 228 (104 ) 60 Net income (loss) attributable to Loews Corporation $ 557 $ (244) $ 62 $ 7 $ (18) $ 364

Basis of Presentation (Policies

Basis of Presentation (Policies)	9 Months Ended
	Sep. 30, 2017
Accounting Policies [Abstract]
Basis of Accounting	Loews Corporation is a holding company. Its subsidiaries are engaged in the following lines of business: commercial property and casualty insurance (CNA Financial Corporation (“CNA”), a 89% owned subsidiary); the operation of offshore oil and gas drilling rigs (Diamond Offshore Drilling, Inc. (“Diamond Offshore”), a 53% owned subsidiary); transportation and storage of natural gas and natural gas liquids (Boardwalk Pipeline Partners, LP (“Boardwalk Pipeline”), a 51% owned subsidiary); the operation of a chain of hotels (Loews Hotels Holding Corporation (“Loews Hotels & Co”), a wholly owned subsidiary); and the manufacture of rigid plastic packaging solutions (Consolidated Container Company LLC, a 99% owned subsidiary). Unless the context otherwise requires, the terms “Company,” “Loews” and “Registrant” as used herein mean Loews Corporation excluding its subsidiaries and the term “Net income (loss) attributable to Loews Corporation” as used herein means Net income (loss) attributable to Loews Corporation shareholders. In the opinion of management, the accompanying unaudited Consolidated Condensed Financial Statements reflect all adjustments (consisting of normal recurring accruals) necessary to present fairly the Company’s financial position as of September 30, 2017 and December 31, 2016, results of operations and comprehensive income for the three and nine months ended September 30, 2017 and 2016 and changes in shareholders’ equity and cash flows for the nine months ended September 30, 2017 and 2016. Net income (loss) for the third quarter and first nine months of each of the years is not necessarily indicative of net income (loss) for that entire year. These Consolidated Condensed Financial Statements should be read in conjunction with the Consolidated Financial Statements in the Company’s Annual Report on Form 10-K
Income Per Share	The Company presents basic and diluted net income (loss) per share on the Consolidated Condensed Statements of Income. Basic net income (loss) per share excludes dilution and is computed by dividing net income (loss) attributable to common stock by the weighted average number of common shares outstanding for the period. Diluted net income 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. 0.4 million and 3.3 million shares for the three months ended September 30, 2017 and 2016 and 0.4 million and 4.7 million shares for the nine months ended September 30, 2017 and 2016 attributable to employee stock-based compensation awards were not included in the diluted weighted average shares outstanding amounts because the effect would have been antidilutive.
Accounting changes	Accounting changes – 2016-09,
Recently issued ASUs	Recently issued ASUs – 2014-09, In January of 2016, the FASB issued ASU 2016-01, – 825-10): available-for-sale In February of 2016, the FASB issued ASU 2016-02, 2014-09. In June of 2016, the FASB issued ASU 2016-13, available-for-sale available-for-sale In October of 2016, the FASB issued ASU 2016-16,

Acquisition of Consolidated C21

Acquisition of Consolidated Container Company (Tables)	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Summary of Preliminary Allocation of Purchase Price to Tangible and Identifiable Intangible Assets Acquired and Liabilities Assumed	The following table summarizes the preliminary allocation of the purchase price to the tangible and intangible assets acquired and liabilities assumed based on their estimated fair value as of the acquisition date and is subject to change within the measurement period. The primary areas that are not yet finalized relate to working capital at closing and determination of tax bases of net assets acquired. (In millions) Cash $ 5 Property, plant and equipment 391 Goodwill 300 Other assets: Inventory 57 Customer relationships 459 Trade name 43 Other 122 Deferred income taxes (17 ) Other liabilities: Accounts payable (52 ) Pension liability (27 ) Other (58 ) $ 1,223

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2017
Text Block [Abstract]
Net Investment Income and Investment Gains (Losses)	Net investment income is as follows: Three Months Ended Nine Months Ended September 30, September 30, 2017 2016 2017 2016 (In millions) Fixed maturity securities $ 455 $ 457 $ 1,367 $ 1,352 Limited partnership investments 67 91 206 98 Short term investments 5 3 13 8 Equity securities 1 1 4 8 Income from trading portfolio (a) 34 11 67 113 Other 10 12 26 34 Total investment income 572 575 1,683 1,613 Investment expenses (15 ) (14 ) (44 ) (43 ) Net investment income $ 557 $ 561 $ 1,639 $ 1,570 (a) Net unrealized gains (losses) related to changes in fair value on trading securities still held were $22 and $8 for the three months ended September 30, 2017 and 2016 and $35 and $63 for the nine months ended September 30, 2017 and 2016. Investment gains (losses) are as follows: Three Months Ended Nine Months Ended September 30, September 30, 2017 2016 2017 2016 (In millions) Fixed maturity securities $ 16 $ 47 $ 92 $ 34 Equity securities (3 ) (5 ) Derivative instruments (1 ) 1 (3 ) (12 ) Short term investments and other 1 4 1 Investment gains (a) $ 16 $ 45 $ 93 $ 18 (a) Gross realized gains on available-for-sale available-for-sale
Components of 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 as follows: Three Months Ended Nine Months Ended September 30, September 30, 2017 2016 2017 2016 (In millions) Fixed maturity securities available-for-sale: Corporate and other bonds $ 4 $ 14 $ 8 $ 43 Asset-backed: Residential mortgage-backed 1 1 1 Other asset-backed 3 Total asset-backed 1 - 1 4 Total fixed maturities available-for-sale 5 14 9 47 Equity securities available-for-sale 4 9 Net OTTI losses recognized in earnings $ 5 $ 18 $ 9 $ 56
Amortized Cost and Fair Values of Securities	The amortized cost and fair values of securities are as follows: Cost or Gross Gross Unrealized Amortized Unrealized Unrealized Estimated OTTI Losses September 30, 2017 Cost Gains Losses Fair Value (Gains) (In millions) Fixed maturity securities: Corporate and other bonds $ 17,965 $ 1,645 $ 26 $ 19,584 States, municipalities and political subdivisions 12,462 1,501 7 13,956 $ (14 ) Asset-backed: Residential mortgage-backed 4,906 127 28 5,005 (28 ) Commercial mortgage-backed 1,858 55 13 1,900 Other asset-backed 1,047 18 4 1,061 Total asset-backed 7,811 200 45 7,966 (28 ) U.S. Treasury and obligations of government-sponsored enterprises 115 3 3 115 Foreign government 439 10 4 445 Redeemable preferred stock 18 2 20 Fixed maturities available-for-sale 38,810 3,361 85 42,086 (42 ) Fixed maturities trading 420 2 1 421 Total fixed maturities 39,230 3,363 86 42,507 (42 ) Equity securities: Common stock 16 7 1 22 Preferred stock 102 5 107 Equity securities available-for-sale 118 12 1 129 - Equity securities trading 474 86 79 481 Total equity securities 592 98 80 610 - Total $ 39,822 $ 3,461 $ 166 $ 43,117 $ (42 ) December 31, 2016 Fixed maturity securities: Corporate and other bonds $ 17,711 $ 1,323 $ 76 $ 18,958 $ (1 ) States, municipalities and political subdivisions 12,060 1,213 33 13,240 (16 ) Asset-backed: Residential mortgage-backed 5,004 120 51 5,073 (28 ) Commercial mortgage-backed 2,016 48 24 2,040 Other asset-backed 1,022 8 5 1,025 Total asset-backed 8,042 176 80 8,138 (28 ) U.S. Treasury and obligations of government-sponsored enterprises 83 10 93 Foreign government 435 13 3 445 Redeemable preferred stock 18 1 19 Fixed maturities available-for-sale 38,349 2,736 192 40,893 (45 ) Fixed maturities trading 598 3 601 Total fixed maturities 38,947 2,739 192 41,494 (45 ) Equity securities: Common stock 13 6 19 Preferred stock 93 2 4 91 Equity securities available-for-sale 106 8 4 110 - Equity securities trading 465 60 86 439 Total equity securities 571 68 90 549 - Total $ 39,518 $ 2,807 $ 282 $ 42,043 $ (45 )
Securities Available-for-Sale in Gross Unrealized Loss Position	The available-for-sale Less than 12 Months 12 Months or Longer Total September 30, 2017 Estimated Gross Estimated Gross Estimated Gross (In millions) Fixed maturity securities: Corporate and other bonds $ 1,216 $ 21 $ 91 $ 5 $ 1,307 $ 26 States, municipalities and political subdivisions 583 6 56 1 639 7 Asset-backed: Residential mortgage-backed 1,522 25 106 3 1,628 28 Commercial mortgage-backed 378 6 138 7 516 13 Other asset-backed 129 4 10 139 4 Total asset-backed 2,029 35 254 10 2,283 45 U.S. Treasury and obligations of government-sponsored enterprises 67 3 6 73 3 Foreign government 191 4 5 196 4 Total fixed maturity securities 4,086 69 412 16 4,498 85 Equity securities: Common stock 2 1 2 1 Preferred stock 16 16 - Total equity securities 18 1 - - 18 1 Total $ 4,104 $ 70 $ 412 $ 16 $ 4,516 $ 86 December 31, 2016 Fixed maturity securities: Corporate and other bonds $ 2,615 $ 61 $ 254 $ 15 $ 2,869 $ 76 States, municipalities and political subdivisions 959 32 23 1 982 33 Asset-backed: Residential mortgage-backed 2,136 44 201 7 2,337 51 Commercial mortgage-backed 756 22 69 2 825 24 Other asset-backed 398 5 24 422 5 Total asset-backed 3,290 71 294 9 3,584 80 U.S. Treasury and obligations of government-sponsored enterprises 5 5 - Foreign government 108 3 108 3 Total fixed maturity securities 6,977 167 571 25 7,548 192 Equity securities 12 13 4 25 4 Total $ 6,989 $ 167 $ 584 $ 29 $ 7,573 $ 196
Pretax Credit Loss Component Reflected in Retained Earnings on Fixed Maturity Securities	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, 2017 and 2016 for which a portion of an OTTI loss was recognized in Other comprehensive income. Three Months Ended Nine Months Ended September 30, September 30, 2017 2016 2017 2016 (In millions) Beginning balance of credit losses on fixed maturity securities $ 30 $ 41 $ 36 $ 53 Reductions for securities sold during the period (2 ) (2 ) (8 ) (14 ) Reductions for securities the Company intends to sell or more likely than not will be required to sell (1 ) (1 ) Ending balance of credit losses on fixed maturity securities $ 28 $ 38 $ 28 $ 38
Available-for-Sale Fixed Maturity Securities by Contractual Maturity	The following table presents available-for-sale September 30, 2017 December 31, 2016 Cost or Estimated Cost or Estimated (In millions) Due in one year or less $ 1,374 $ 1,404 $ 1,779 $ 1,828 Due after one year through five years 7,931 8,293 7,566 7,955 Due after five years through ten years 15,853 16,574 15,892 16,332 Due after ten years 13,652 15,815 13,112 14,778 Total $ 38,810 $ 42,086 $ 38,349 $ 40,893
Summary of Aggregate Contractual or Notional Amounts and Gross Estimated Fair Values Related to Derivative Financial Instruments	A summary of the aggregate contractual or notional amounts and gross estimated fair values related to derivative financial instruments follows. The contractual or notional amounts for derivatives are used to calculate the exchange of contractual payments under the agreements and may not be representative of the potential for gain or loss on these instruments. Gross estimated fair values of derivative positions are currently presented in Equity securities, Receivables and Payable to brokers on the Consolidated Condensed Balance Sheets. September 30, 2017 December 31, 2016 Contractual/ Contractual/ Notional Estimated Fair Value Notional Estimated Fair Value Amount Asset (Liability) Amount Asset (Liability) (In millions) With hedge designation: Interest rate swaps $ 500 Without hedge designation: Equity markets: Options – purchased 267 $ 15 $ 223 $ 14 – written 296 $ (8 ) 267 $ (8 ) Futures – short 249 (1 ) 225 1 Commodity futures – long 39 42 Embedded derivative on funds withheld liability 170 (1 ) 174 3

Fair Value (Tables)

Fair Value (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Assets and Liabilities Measured at Fair Value on Recurring Basis	Assets and liabilities measured at fair value on a recurring basis are presented in the following tables: September 30, 2017 Level 1 Level 2 Level 3 Total (In millions) Fixed maturity securities: Corporate and other bonds $ 19,465 $ 119 $ 19,584 States, municipalities and political subdivisions 13,955 1 13,956 Asset-backed: Residential mortgage-backed 4,829 176 5,005 Commercial mortgage-backed 1,876 24 1,900 Other asset-backed 915 146 1,061 Total asset-backed 7,620 346 7,966 U.S. Treasury and obligations of government-sponsored enterprises $ 115 115 Foreign government 445 445 Redeemable preferred stock 20 20 Fixed maturities available-for-sale 135 41,485 466 42,086 Fixed maturities trading 9 407 5 421 Total fixed maturities $ 144 $ 41,892 $ 471 $ 42,507 Equity securities available-for-sale $ 110 $ 19 $ 129 Equity securities trading 479 2 481 Total equity securities $ 589 $ - $ 21 $ 610 Short term investments $ 4,019 $ 876 $ 4,895 Other invested assets 61 5 66 Payable to brokers (9 ) (9 ) December 31, 2016 Level 1 Level 2 Level 3 Total (In millions) Fixed maturity securities: Corporate and other bonds $ 18,828 $ 130 $ 18,958 States, municipalities and political subdivisions 13,239 1 13,240 Asset-backed: Residential mortgage-backed 4,944 129 5,073 Commercial mortgage-backed 2,027 13 2,040 Other asset-backed 968 57 1,025 Total asset-backed 7,939 199 8,138 U.S. Treasury and obligations of government-sponsored enterprises $ 93 93 Foreign government 445 445 Redeemable preferred stock 19 19 Fixed maturities available-for-sale 112 40,451 330 40,893 Fixed maturities trading 595 6 601 Total fixed maturities $ 112 $ 41,046 $ 336 $ 41,494 Equity securities available-for-sale $ 91 $ 19 $ 110 Equity securities trading 438 1 439 Total equity securities $ 529 $ - $ 20 $ 549 Short term investments $ 3,833 $ 853 $ 4,686 Other invested assets 55 5 60 Receivables 1 1 Life settlement contracts $ 58 58 Payable to brokers (44 ) (44 )
Reconciliations of Assets and Liabilities Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs	The following tables present reconciliations for all assets and liabilities measured at fair value on a recurring basis using significant unobservable inputs (Level 3) for the three and nine months ended September 30, 2017 and 2016: Net Realized Gains Unrealized (Losses) 2017 Balance, Included in Included in Purchases Sales Settlements Transfers Transfers Balance, Liabilities (In millions) Fixed maturity securities: Corporate and other bonds $ 100 $ 1 $ 1 $ 13 $ (11 ) $ 15 $ 119 States, municipalities and political subdivisions 1 1 Asset-backed: Residential mortgage-backed 123 1 1 (7 ) 58 176 Commercial mortgage-backed 13 (1 ) 12 (2 ) 2 24 Other asset-backed 82 (1 ) 1 27 (4 ) 41 146 Total asset-backed 218 - 1 39 $ - (13 ) 101 $ - 346 $ - Fixed maturities available-for-sale 319 1 2 52 (24 ) 116 466 Fixed maturities trading 5 5 Total fixed maturities $ 324 $ 1 $ 2 $ 52 $ - $ (24 ) $ 116 $ - $ 471 $ - Equity securities available-for-sale $ 19 $ 19 Equity securities trading 1 $ 1 2 Total equity securities $ 20 $ - $ - $ 1 $ - $ - $ - $ - $ 21 $ - Life settlement contracts $ 1 $ (1) $ - Net Realized Gains Transfers Transfers Unrealized (Losses) 3 Assets and Liabilities 2016 Balance, Included in Included in Purchases Sales Settlements into out of Balance, Held at (In millions) Fixed maturity securities: Corporate and other bonds $ 242 $ 1 $ 7 $ 16 $ (5 ) $ 261 States, municipalities and political subdivisions 2 (1 ) 1 Asset-backed: Residential mortgage-backed 134 (1 ) 5 (1 ) $ (58 ) 79 Commercial mortgage-backed 11 23 (8 ) (2 ) 24 Other asset-backed 45 34 (36 ) 43 Total asset-backed 190 - (1 ) 62 $ - (9 ) $ - (96 ) 146 $ - Fixed maturities available-for-sale 434 1 6 78 (15 ) (96 ) 408 Fixed maturities trading 6 6 (1 ) Total fixed maturities $ 440 $ 1 $ 6 $ 78 $ - $ (15 ) $ - $ (96 ) $ 414 $ (1 ) Equity securities available-for-sale $ 19 $ (1 ) $ 1 $ 19 $ (2 ) Equity securities trading 2 $ (1 ) 1 (1 ) Total equity securities $ 21 $ (1 ) $ 1 $ (1 ) $ - $ - $ - $ - $ 20 $ (3 ) Life settlement contracts $ 67 $ 67 Derivative financial instruments, net 1 $ (1 ) - Net Realized Gains Unrealized (Losses) 2017 Balance, January 1 Included in Included in Purchases Sales Settlements Transfers Transfers Balance, Liabilities (In millions) Fixed maturity securities: Corporate and other bonds $ 130 $ 1 $ 2 $ 18 $ (1) $ (36 ) $ 15 $ (10 ) $ 119 States, municipalities and political subdivisions 1 1 Asset-backed: Residential mortgage-backed 129 3 4 (18 ) 58 176 Commercial mortgage-backed 13 (1 ) 12 (2 ) 2 24 Other asset-backed 57 (2 ) 1 78 (6 ) 93 (75 ) 146 Total asset-backed 199 1 4 90 - (26 ) 153 (75 ) 346 $ - Fixed maturities available-for-sale 330 2 6 108 (1) (62 ) 168 (85 ) 466 Fixed maturities trading 6 (1 ) 5 (1 ) Total fixed maturities $ 336 $ 1 $ 6 $ 108 $ (1) $ (62 ) $ 168 $ (85 ) $ 471 $ (1 ) Equity securities available-for-sale $ 19 $ 2 $ 1 $ (3) $ 19 Equity securities trading 1 1 2 Total equity securities $ 20 $ - $ 2 $ 2 $ (3) $ - $ - $ - $ 21 $ - Life settlement contracts $ 58 $ 6 $ (59) $ (5 ) $ - Derivative financial instruments, net - 1 (1) - Net Realized Gains Transfers Transfers Unrealized (Losses) 3 Assets and 2016 Balance, January 1 Included in Included in Purchases Sales Settlements into out of Balance, Held at (In millions) Fixed maturity securities: Corporate and other bonds $ 168 $ 1 $ 14 $ 163 $ (36 ) $ (15 ) $ (34 ) $ 261 States, municipalities and political subdivisions 2 (1 ) 1 Asset-backed: Residential mortgage-backed 134 2 (2 ) 15 (10 ) (60 ) 79 Commercial mortgage-backed 22 32 (17 ) $ 3 (16 ) 24 Other asset-backed 53 2 69 (25 ) (1 ) 2 (57 ) 43 Total asset-backed 209 2 - 116 (25 ) (28 ) 5 (133 ) 146 $ - Fixed maturities available-for-sale 379 3 14 279 (61 ) (44 ) 5 (167 ) 408 Fixed maturities trading 85 5 2 (86 ) 6 3 Total fixed maturities $ 464 $ 8 $ 14 $ 281 $ (147 ) $ (44 ) $ 5 $ (167 ) $ 414 $ 3 Equity securities available-for-sale $ 20 $ (1 ) $ 19 $ (2 ) Equity securities trading 1 1 $ (1 ) 1 Total equity securities $ 21 $ - $ - $ - $ (1 ) $ - $ - $ - $ 20 $ (2 ) Life settlement contracts $ 74 $ 10 $ (17 ) $ 67 $ 2 Derivative financial instruments, net 3 (4 ) $ (2 ) $ 3 - (3 )
Quantitative Information about Significant Unobservable Inputs Utilized by Company in 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 measurement 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 unobservable inputs from these broker quotes is neither provided nor reasonably available to the Company. The valuation of life settlement contracts was based on the terms of the sale of the contracts to a third party; therefore the contracts are not included in the tables below. September 30, 2017 Estimated Fair Value Valuation Techniques Unobservable Inputs Range (Weighted Average) (In millions) Fixed maturity securities $ 139 Discounted cash flow Credit spread 1% – 12% (3%) December 31, 2016 Fixed maturity securities $ 106 Discounted cash flow Credit spread 2% – 40% (4%)
Carrying Amount, Estimated Fair Value and Level of Fair Value Hierarchy of Company's Financial Assets and Liabilities	The carrying amount, estimated fair value and the level of the fair value hierarchy of the Company’s financial assets and liabilities which are not measured at fair value on the Consolidated Condensed Balance Sheets are presented in the following tables. The carrying amounts and estimated fair values of short term debt and long term debt exclude capital lease obligations. The carrying amounts reported on the Consolidated Condensed Balance Sheets for cash and short term investments not carried at fair value and certain other assets and liabilities approximate fair value due to the short term nature of these items. Carrying Estimated Fair Value September 30, 2017 Amount Level 1 Level 2 Level 3 Total (In millions) Assets: Other invested assets, primarily mortgage loans $ 722 $ 731 $ 731 Liabilities: Short term debt 191 $ 152 41 193 Long term debt 11,222 10,316 1,216 11,532 December 31, 2016 Assets: Other invested assets, primarily mortgage loans $ 591 $ 594 $ 594 Liabilities: Short term debt 107 $ 104 3 107 Long term debt 10,655 10,150 646 10,796

Claim and Claim Adjustment Ex24

Claim and Claim Adjustment Expense Reserves (Tables)	9 Months Ended
	Sep. 30, 2017
Insurance [Abstract]
Reconciliation of Claim and Claim Adjustment Expense Reserves	The following table presents a reconciliation between beginning and ending claim and claim adjustment expense reserves, including claim and claim adjustment expense reserves of non-core Nine Months Ended September 30 2017 2016 (In millions) Reserves, beginning of year: Gross $ 22,343 $ 22,663 Ceded 4,094 4,087 Net reserves, beginning of year 18,249 18,576 Net incurred claim and claim adjustment expenses: Provision for insured events of current year 3,949 3,799 Decrease in provision for insured events of prior years (284 ) (332 ) Amortization of discount 138 134 Total net incurred (a) 3,803 3,601 Net payments attributable to: Current year events (560 ) (591 ) Prior year events (3,401 ) (3,209 ) Total net payments (3,961 ) (3,800 ) Foreign currency translation adjustment and other 110 39 Net reserves, end of period 18,201 18,416 Ceded reserves, end of period 4,008 4,256 Gross reserves, end of period $ 22,209 $ 22,672 (a) Total net incurred above does not agree to Insurance claims and policyholders’ benefits as reflected in the Consolidated Condensed Statements of Income 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 and discussion present net prior year development: Three Months Ended Nine Months Ended 2017 2016 2017 2016 (In millions) Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development $ (115 ) $ (132 ) $ (227 ) $ (282 ) Pretax (favorable) unfavorable premium development (19 ) (5 ) (2 ) (27 ) Total pretax (favorable) unfavorable net prior year development $ (134 ) $ (137 ) $ (229 ) $ (309 )
Details of the Net Prior Year Claim and Allocated Claim Adjustment Expense Reserve Development ("development")	The following table and discussion present details of the net prior year claim and allocated claim adjustment expense reserve development (“development”): Three Months Ended Nine Months Ended 2017 2016 2017 2016 (In millions) Medical professional liability $ 1 $ 13 $ 5 $ (17 ) Other professional liability and management liability (27 ) (48 ) (96 ) (98 ) Surety (82 ) (63 ) (82 ) (63 ) Commercial auto (14 ) (12 ) (40 ) (47 ) General liability 7 14 6 (38 ) Workers’ compensation 7 (6 ) (39 ) 48 Other (7 ) (30 ) 19 (67 ) Total pretax (favorable) unfavorable development $ (115 ) $ (132 ) $ (227 ) $ (282 )
Schedule of Impact of Loss Portfolio Transfer on the Consolidated Statement of Operations	The following table presents the impact of the loss portfolio transfer on the Consolidated Condensed Statements of Income. Three Months Ended Nine Months Ended 2017 2016 2017 2016 (In millions) Net A&EP adverse development before consideration of LPT $ - $ - $ 60 $ 200 Retroactive reinsurance benefit recognized (17 ) (12 ) (60 ) (94 ) Pretax impact of A&EP reserve development and the LPT $ (17 ) $ (12 ) $ - $ 106

Shareholders' Equity (Tables)

Shareholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2017
Equity [Abstract]
Components of Accumulated Other Comprehensive Income	The tables below present the changes in AOCI by component for the three and nine months ended September 30, 2016 and 2017: OTTI Unrealized on Investments Cash Flow Pension Foreign Total (In millions) Balance, July 1, 2016 $ 28 $ 838 $ (2 ) $ (639 ) $ (106 ) $ 119 Other comprehensive income (loss) before reclassifications, after tax of $(4), $(32), $0, $0 and $0 7 69 (24 ) 52 Reclassification of (gains) losses from accumulated other comprehensive income, after tax of $2, $13, $0, $(4) and $0 (4 ) (27 ) 1 7 (23 ) Other comprehensive income (loss) 3 42 1 7 (24 ) 29 Amounts attributable to noncontrolling interests (1 ) (4 ) (1 ) 2 (4 ) Balance, September 30, 2016 $ 30 $ 876 $ (2 ) $ (632 ) $ (128 ) $ 144 Balance, July 1, 2017 $ 23 $ 705 $ (2 ) $ (632 ) $ (130 ) $ (36 ) Other comprehensive income (loss) before reclassifications, after tax of $0, $(20), $0, $0 and $0 1 35 (2 ) 41 75 Reclassification of (gains) losses from accumulated other comprehensive income, after tax of $0, $4, $0, $(6) and $0 (12 ) 3 11 2 Other comprehensive income 1 23 1 11 41 77 Amounts attributable to noncontrolling interests (3 ) (1 ) (1 ) (4 ) (9 ) Balance, September 30, 2017 $ 24 $ 725 $ (2 ) $ (622 ) $ (93 ) $ 32 OTTI Unrealized Cash Flow Pension Foreign Total (In millions) Balance, January 1, 2016 $ 24 $ 347 $ (3 ) $ (649 ) $ (76 ) $ (357 ) Other comprehensive income (loss) before reclassifications, after tax of $(5), $(304), $0, $0 and $0 9 608 (58 ) 559 Reclassification of (gains) losses from accumulated other comprehensive income, after tax of $1, $12, $0, $(11) and $0 (2 ) (17 ) 2 20 3 Other comprehensive income (loss) 7 591 2 20 (58 ) 562 Amounts attributable to noncontrolling interests (1 ) (62 ) (1 ) (3 ) 6 (61 ) Balance, September 30, 2016 $ 30 $ 876 $ (2 ) $ (632 ) $ (128 ) $ 144 Balance, January 1, 2017 $ 27 $ 576 $ (2 ) $ (646 ) $ (178 ) $ (223 ) Other comprehensive income (loss) before reclassifications, after tax of $0, $(130), $0, $0 and $0 228 (3 ) 94 319 Reclassification of (gains) losses from accumulated other comprehensive income, after tax of $1, $28, $0, $(13) and $0 (3 ) (61 ) 4 26 (34 ) Other comprehensive income (loss) (3 ) 167 1 26 94 285 Amounts attributable to noncontrolling interests (18 ) (1 ) (2 ) (9 ) (30 ) Balance, September 30, 2017 $ 24 $ 725 $ (2 ) $ (622 ) $ (93 ) $ 32

Benefit Plans (Tables)

Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2017
Retirement Benefits [Abstract]
Components of Net Periodic Benefit Cost	The following table presents the components of net periodic benefit cost for the plans: Pension Benefits Three Months Ended Nine Months Ended 2017 2016 2017 2016 (In millions) Service cost $ 2 $ 2 $ 6 $ 6 Interest cost 30 33 89 97 Expected return on plan assets (43 ) (45 ) (129 ) (133 ) Amortization of unrecognized net loss 10 11 32 34 Settlement charge 7 1 10 3 Net periodic benefit cost $ 6 $ 2 $ 8 $ 7 Other Postretirement Benefits Three Months Ended Nine Months Ended 2017 2016 2017 2016 (In millions) Service cost $ 1 $ 1 Interest cost $ 1 1 $ 2 2 Expected return on plan assets (1 ) (1 ) (3 ) (3 ) Amortization of unrecognized prior service benefit (1 ) (1 ) (2 ) (3 ) Net periodic benefit cost $ (1 ) $ - $ (3 ) $ (3 )

Segments (Tables)

Segments (Tables)	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Consolidating Statement of Income by Segment	Statements of Income by segment are presented in the following tables. Three Months Ended September 30, 2017 CNA Diamond Boardwalk Loews Corporate Total (In millions) Revenues: Insurance premiums $ 1,806 $ 1,806 Net investment income 509 $ 48 557 Investment gains 16 16 Contract drilling revenues $ 357 357 Other revenues 110 11 $ 301 $ 162 201 785 Total 2,441 368 301 162 249 3,521 Expenses: Insurance claims and policyholders’ benefits 1,480 1,480 Amortization of deferred acquisition costs 309 309 Contract drilling expenses 198 198 Other operating expenses 379 109 191 147 221 1,047 Interest 83 64 41 7 28 223 Total 2,251 371 232 154 249 3,257 Income (loss) before income tax 190 (3 ) 69 8 - 264 Income tax (expense) benefit (44 ) 14 (18 ) (4 ) (52) Net income 146 11 51 4 - 212 Amounts attributable to noncontrolling interests (16 ) (5 ) (34 ) (55) Net income attributable to Loews Corporation $ 130 $ 6 $ 17 $ 4 $ - $ 157 Three Months Ended September 30, 2016 CNA Financial Diamond Boardwalk Loews Corporate Total (In millions) Revenues: Insurance premiums $ 1,767 $ 1,767 Net investment income 524 $ 1 $ 36 561 Investment gains 45 45 Contract drilling revenues 340 340 Other revenues 97 9 $ 306 $ 161 1 574 Total 2,433 350 306 161 37 3,287 Expenses: Insurance claims and policyholders’ benefits 1,202 1,202 Amortization of deferred acquisition costs 314 314 Contract drilling expenses 187 187 Other operating expenses 402 108 212 151 25 898 Interest 39 19 48 6 18 130 Total 1,957 314 260 157 43 2,731 Income (loss) before income tax 476 36 46 4 (6 ) 556 Income tax (expense) benefit (132 ) (22 ) (9 ) (1 ) 1 (163) Net income (loss) 344 14 37 3 (5 ) 393 Amounts attributable to noncontrolling interests (36 ) (7 ) (23 ) (66) Net income (loss) attributable to Loews Corporation $ 308 $ 7 $ 14 $ 3 $ (5 ) $ 327 Nine Months Ended September 30, 2017 CNA Diamond Boardwalk Loews Corporate Total (In millions) Revenues: Insurance premiums $ 5,185 $ 5,185 Net investment income 1,529 $ 1 $ 109 1,639 Investment gains 93 93 Contract drilling revenues 1,113 1,113 Other revenues 329 30 $ 987 $ 510 294 2,150 Total 7,136 1,144 987 510 403 10,180 Expenses: Insurance claims and policyholders’ benefits 4,053 4,053 Amortization of deferred acquisition costs 926 926 Contract drilling expenses 598 598 Other operating expenses 1,086 414 646 443 389 2,978 Interest 166 119 131 20 68 504 Total 6,231 1,131 777 463 457 9,059 Income (loss) before income tax 905 13 210 47 (54 ) 1,121 Income tax (expense) benefit (226 ) 35 (46 ) (23 ) 20 (240) Net income (loss) 679 48 164 24 (34 ) 881 Amounts attributable to noncontrolling interests (71 ) (23 ) (104 ) (198) Net income (loss) attributable to Loews Corporation $ 608 $ 25 $ 60 $ 24 $ (34) $ 683 Nine Months Ended September 30, 2016 CNA Financial Diamond Boardwalk Loews Corporate Total (In millions) Revenues: Insurance premiums $ 5,196 $ 5,196 Net investment income 1,461 $ 1 $ 108 1,570 Investment gains (losses) 30 (12 ) 18 Contract drilling revenues 1,141 1,141 Other revenues 297 69 $ 961 $ 513 2 1,842 Total 6,984 1,199 961 513 110 9,767 Expenses: Insurance claims and policyholders’ benefits 3,949 3,949 Amortization of deferred acquisition costs 926 926 Contract drilling expenses 598 598 Other operating expenses 1,158 1,082 615 479 82 3,416 Interest 127 69 136 17 54 403 Total 6,160 1,749 751 496 136 9,292 Income (loss) before income tax 824 (550 ) 210 17 (26 ) 475 Income tax (expense) benefit (203 ) 78 (44 ) (10 ) 8 (171) Net income (loss) 621 (472 ) 166 7 (18 ) 304 Amounts attributable to noncontrolling interests (64 ) 228 (104 ) 60 Net income (loss) attributable to Loews Corporation $ 557 $ (244) $ 62 $ 7 $ (18) $ 364

Basis of Presentation - Additio

Basis of Presentation - Additional Information (Detail) - shares shares in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Subsidiary or Equity Method Investee [Line Items]
Shares excluded from diluted EPS calculation	0.4	3.3	0.4	4.7
CNA Financial [Member]
Subsidiary or Equity Method Investee [Line Items]
Subsidiary ownership percentage			89.00%
Diamond Offshore Drilling, Inc. [Member]
Subsidiary or Equity Method Investee [Line Items]
Subsidiary ownership percentage			53.00%
Boardwalk Pipeline Partners, LP [Member]
Subsidiary or Equity Method Investee [Line Items]
Subsidiary ownership percentage			51.00%
Consolidated Container Company [Member]
Subsidiary or Equity Method Investee [Line Items]
Subsidiary ownership percentage			99.00%

Acquisition of Consolidated C29

Acquisition of Consolidated Container Company - Additional Information (Detail) - USD ($) $ in Millions	May 22, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Business Acquisition [Line Items]
Revenue		$ 3,521	$ 3,287		$ 10,180	$ 9,767
Corporate [Member]
Business Acquisition [Line Items]
Revenue		249	$ 37		403	$ 110
CCC Acquisition Holdings, Inc. [Member]
Business Acquisition [Line Items]
Payments for acquisition	$ 1,200
Cash payments funding acquisition					620
Goodwill deductible for tax purposes		94		$ 94	$ 94
CCC Acquisition Holdings, Inc. [Member] | Customer Relationships [Member]
Business Acquisition [Line Items]
Useful life of intangible assets					21 years
CCC Acquisition Holdings, Inc. [Member] | Trade Name [Member]
Business Acquisition [Line Items]
Useful life of intangible assets					10 years
Consolidated Container Company [Member]
Business Acquisition [Line Items]
Revenue							$ 788
Debt financing proceeds funding acquisition					$ 600
Consolidated Container Company [Member] | Corporate [Member]
Business Acquisition [Line Items]
Revenue		$ 202		$ 293

Acquisition of Consolidated C30

Acquisition of Consolidated Container Company - Summary of Preliminary Allocation of Purchase Price to Tangible and Identifiable Intangible Assets Acquired and Liabilities Assumed (Detail) - CCC Acquisition Holdings, Inc. [Member] $ in Millions	May 22, 2017USD ($)
Business Acquisition, Contingent Consideration [Line Items]
Cash	$ 5
Property, plant and equipment	391
Goodwill	300
Other assets:
Inventory	57
Other	122
Deferred income taxes	(17)
Other liabilities:
Accounts payable	(52)
Pension liability	(27)
Other	(58)
Total	1,223
Customer Relationships [Member]
Other assets:
Intangibles	459
Trade Name [Member]
Other assets:
Intangibles	$ 43

Investments - Net Investment In

Investments - Net Investment Income and Investment Gains (Losses) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net Investment Income [Line Items]
Total investment income	$ 572	$ 575	$ 1,683	$ 1,613
Investment expenses	(15)	(14)	(44)	(43)
Investment gains	16	45	93	18
Net investment income	557	561	1,639	1,570
Fixed Maturity Securities [Member]
Net Investment Income [Line Items]
Total investment income	455	457	1,367	1,352
Investment gains	16	47	92	34
Equity Securities [Member]
Net Investment Income [Line Items]
Total investment income	1	1	4	8
Investment gains		(3)		(5)
Derivative Instruments [Member]
Net Investment Income [Line Items]
Investment gains	(1)	1	(3)	(12)
Short Term Investments [Member]
Net Investment Income [Line Items]
Total investment income	5	3	13	8
Investment gains	1		4	1
Limited Partnership Investments [Member]
Net Investment Income [Line Items]
Total investment income	67	91	206	98
Income from Trading Portfolio [Member]
Net Investment Income [Line Items]
Total investment income	34	11	67	113
Other [Member]
Net Investment Income [Line Items]
Total investment income	$ 10	$ 12	$ 26	$ 34

Investments - Net Investment 32

Investments - Net Investment Income and Investment Gains (Losses) (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Net Investment Income [Line Items]
Net unrealized gains (losses) on trading securities	$ 22	$ 8	$ 35	$ 63
Fixed Maturity Securities [Member]
Net Investment Income [Line Items]
Gross realized gains on available-for-sale securities	34	68	140	157
Gross realized losses on available-for-sale securities	$ 18	$ 24	$ 48	$ 128

Investments - Components of Oth

Investments - Components of Other-than-Temporary Impairment Losses Recognized in Earnings by Asset Type (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Net OTTI losses recognized in earnings	$ 5	$ 18	$ 9	$ 56
Corporate and Other Bonds [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Net OTTI losses recognized in earnings	4	14	8	43
Residential Mortgage-Backed [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Net OTTI losses recognized in earnings	1		1	1
Other Asset-Backed [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Net OTTI losses recognized in earnings				3
Total Asset-Backed [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Net OTTI losses recognized in earnings	1		1	4
Total Fixed Maturities Available-for-Sale [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Net OTTI losses recognized in earnings	$ 5	14	$ 9	47
Common Stock [Member]
Other than Temporary Impairment, Credit Losses Recognized in Earnings [Line Items]
Net OTTI losses recognized in earnings		$ 4		$ 9

Investments - Amortized Cost an

Investments - Amortized Cost and Fair Values of Securities (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost or Amortized Cost	$ 39,822	$ 39,518
Gross Unrealized Gains	3,461	2,807
Gross Unrealized Losses	166	282
Estimated Fair Value	43,117	42,043
Unrealized OTTI Losses (Gains)	(42)	(45)
Fixed Maturity Securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost or Amortized Cost	39,230	38,947
Gross Unrealized Gains	3,363	2,739
Gross Unrealized Losses	86	192
Estimated Fair Value	42,507	41,494
Unrealized OTTI Losses (Gains)	(42)	(45)
Corporate and Other Bonds [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost or Amortized Cost	17,965	17,711
Gross Unrealized Gains	1,645	1,323
Gross Unrealized Losses	26	76
Estimated Fair Value	19,584	18,958
Unrealized OTTI Losses (Gains)		(1)
States, Municipalities and Political Subdivisions [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost or Amortized Cost	12,462	12,060
Gross Unrealized Gains	1,501	1,213
Gross Unrealized Losses	7	33
Estimated Fair Value	13,956	13,240
Unrealized OTTI Losses (Gains)	(14)	(16)
Residential Mortgage-Backed [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost or Amortized Cost	4,906	5,004
Gross Unrealized Gains	127	120
Gross Unrealized Losses	28	51
Estimated Fair Value	5,005	5,073
Unrealized OTTI Losses (Gains)	(28)	(28)
Commercial Mortgage-Backed [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost or Amortized Cost	1,858	2,016
Gross Unrealized Gains	55	48
Gross Unrealized Losses	13	24
Estimated Fair Value	1,900	2,040
Other Asset-Backed [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost or Amortized Cost	1,047	1,022
Gross Unrealized Gains	18	8
Gross Unrealized Losses	4	5
Estimated Fair Value	1,061	1,025
Total Asset-Backed [Member] | Fixed Maturity Securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost or Amortized Cost	7,811	8,042
Gross Unrealized Gains	200	176
Gross Unrealized Losses	45	80
Estimated Fair Value	7,966	8,138
Unrealized OTTI Losses (Gains)	(28)	(28)
U.S. Treasury and Obligations of Government-Sponsored Enterprises [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost or Amortized Cost	115	83
Gross Unrealized Gains	3	10
Gross Unrealized Losses	3
Estimated Fair Value	115	93
Foreign Government [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost or Amortized Cost	439	435
Gross Unrealized Gains	10	13
Gross Unrealized Losses	4	3
Estimated Fair Value	445	445
Redeemable Preferred Stock [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost or Amortized Cost	18	18
Gross Unrealized Gains	2	1
Estimated Fair Value	20	19
Total Fixed Maturities Available-for-Sale [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost or Amortized Cost	38,810	38,349
Gross Unrealized Gains	3,361	2,736
Gross Unrealized Losses	85	192
Estimated Fair Value	42,086	40,893
Unrealized OTTI Losses (Gains)	(42)	(45)
Fixed Maturities Trading [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost or Amortized Cost	420	598
Gross Unrealized Gains	2	3
Gross Unrealized Losses	1
Estimated Fair Value	421	601
Common Stock [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost or Amortized Cost	16	13
Gross Unrealized Gains	7	6
Gross Unrealized Losses	1
Estimated Fair Value	22	19
Preferred Stock [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost or Amortized Cost	102	93
Gross Unrealized Gains	5	2
Gross Unrealized Losses		4
Estimated Fair Value	107	91
Equity Securities Available-for-Sale [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost or Amortized Cost	118	106
Gross Unrealized Gains	12	8
Gross Unrealized Losses	1	4
Estimated Fair Value	129	110
Equity Securities Trading [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost or Amortized Cost	474	465
Gross Unrealized Gains	86	60
Gross Unrealized Losses	79	86
Estimated Fair Value	481	439
Equity Securities [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Cost or Amortized Cost	592	571
Gross Unrealized Gains	98	68
Gross Unrealized Losses	80	90
Estimated Fair Value	$ 610	$ 549

Investments - Additional Inform

Investments - Additional Information (Detail) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Net unrealized gains on investments included in "AOCI"	$ 1,200,000,000	$ 909,000,000
Additional other than temporary impairment losses	$ 0

Investments - Securities Availa

Investments - Securities Available-for-Sale in Gross Unrealized Loss Position (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Corporate and Other Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	$ 1,216	$ 2,615
Gross Unrealized Losses, Less than 12 Months	21	61
Estimated Fair Value, 12 Months or Longer	91	254
Gross Unrealized Losses, 12 Months or Longer	5	15
Total Estimated Fair Value	1,307	2,869
Total Gross Unrealized Losses	26	76
States, Municipalities and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	583	959
Gross Unrealized Losses, Less than 12 Months	6	32
Estimated Fair Value, 12 Months or Longer	56	23
Gross Unrealized Losses, 12 Months or Longer	1	1
Total Estimated Fair Value	639	982
Total Gross Unrealized Losses	7	33
Residential Mortgage-Backed [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	1,522	2,136
Gross Unrealized Losses, Less than 12 Months	25	44
Estimated Fair Value, 12 Months or Longer	106	201
Gross Unrealized Losses, 12 Months or Longer	3	7
Total Estimated Fair Value	1,628	2,337
Total Gross Unrealized Losses	28	51
Commercial Mortgage-Backed [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	378	756
Gross Unrealized Losses, Less than 12 Months	6	22
Estimated Fair Value, 12 Months or Longer	138	69
Gross Unrealized Losses, 12 Months or Longer	7	2
Total Estimated Fair Value	516	825
Total Gross Unrealized Losses	13	24
Other Asset-Backed [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	129	398
Gross Unrealized Losses, Less than 12 Months	4	5
Estimated Fair Value, 12 Months or Longer	10	24
Total Estimated Fair Value	139	422
Total Gross Unrealized Losses	4	5
Total Asset-Backed [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	2,029	3,290
Gross Unrealized Losses, Less than 12 Months	35	71
Estimated Fair Value, 12 Months or Longer	254	294
Gross Unrealized Losses, 12 Months or Longer	10	9
Total Estimated Fair Value	2,283	3,584
Total Gross Unrealized Losses	45	80
U.S. Treasury and Obligations of Government-Sponsored Enterprises [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	67	5
Gross Unrealized Losses, Less than 12 Months	3
Estimated Fair Value, 12 Months or Longer	6
Total Estimated Fair Value	73	5
Total Gross Unrealized Losses	3
Foreign Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	191	108
Gross Unrealized Losses, Less than 12 Months	4	3
Estimated Fair Value, 12 Months or Longer	5
Total Estimated Fair Value	196	108
Total Gross Unrealized Losses	4	3
Total Fixed Maturities Available-for-Sale [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	4,086	6,977
Gross Unrealized Losses, Less than 12 Months	69	167
Estimated Fair Value, 12 Months or Longer	412	571
Gross Unrealized Losses, 12 Months or Longer	16	25
Total Estimated Fair Value	4,498	7,548
Total Gross Unrealized Losses	85	192
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	18	12
Gross Unrealized Losses, Less than 12 Months	1
Estimated Fair Value, 12 Months or Longer		13
Gross Unrealized Losses, 12 Months or Longer		4
Total Estimated Fair Value	18	25
Total Gross Unrealized Losses	1	4
Fixed Maturity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	4,104	6,989
Gross Unrealized Losses, Less than 12 Months	70	167
Estimated Fair Value, 12 Months or Longer	412	584
Gross Unrealized Losses, 12 Months or Longer	16	29
Total Estimated Fair Value	4,516	7,573
Total Gross Unrealized Losses	86	$ 196
Common Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	2
Gross Unrealized Losses, Less than 12 Months	1
Total Estimated Fair Value	2
Total Gross Unrealized Losses	1
Preferred Stock [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value, Less than 12 Months	16
Total Estimated Fair Value	$ 16

Investments - Pretax Credit Los

Investments - Pretax Credit Loss Component Reflected in Retained Earnings on Fixed Maturity Securities (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Investments, Debt and Equity Securities [Abstract]
Beginning balance of credit losses on fixed maturity securities	$ 30	$ 41	$ 36	$ 53
Reductions for securities sold during the period	(2)	(2)	(8)	(14)
Reductions for securities the Company intends to sell or more likely than not will be required to sell		(1)		(1)
Ending balance of credit losses on fixed maturity securities	$ 28	$ 38	$ 28	$ 38

Investments - Available-for-Sal

Investments - Available-for-Sale Fixed Maturity Securities by Contractual Maturity (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Cost or Amortized Cost, Due in one year or less	$ 1,374	$ 1,779
Cost or Amortized Cost, Due after one year through five years	7,931	7,566
Cost or Amortized Cost, Due after five years through ten years	15,853	15,892
Cost or Amortized Cost, Due after ten years	13,652	13,112
Cost or Amortized Cost, Total	38,810	38,349
Estimated Fair Value, Due in one year or less	1,404	1,828
Estimated Fair Value, Due after one year through five years	8,293	7,955
Estimated Fair Value, Due after five years through ten years	16,574	16,332
Estimated Fair Value, Due after ten years	15,815	14,778
Estimated Fair Value, Total	$ 42,086	$ 40,893

Investments - Summary of Aggreg

Investments - Summary of Aggregate Contractual or Notional Amounts and Gross Estimated Fair Values Related to Derivative Financial Instruments (Detail) - USD ($)	Sep. 30, 2017	Dec. 31, 2016
Embedded Derivative on Funds Withheld Liability [Member]
Derivative [Line Items]
Contractual/Notional Amount	$ 170,000,000	$ 174,000,000
Estimated Fair Value, Asset		3,000,000
Estimated Fair Value, (Liability)	(1,000,000)
With Hedge Designation [Member] | Interest Rate Swaps [Member]
Derivative [Line Items]
Contractual/Notional Amount	500,000,000
Without Hedge Designation [Member] | Equity Markets, Options - Purchased [Member]
Derivative [Line Items]
Contractual/Notional Amount	267,000,000	223,000,000
Estimated Fair Value, Asset	15,000,000	14,000,000
Without Hedge Designation [Member] | Equity Markets, Options - Written [Member]
Derivative [Line Items]
Contractual/Notional Amount	296,000,000	267,000,000
Estimated Fair Value, (Liability)	(8,000,000)	(8,000,000)
Without Hedge Designation [Member] | Equity Futures [Member] | Short [Member]
Derivative [Line Items]
Contractual/Notional Amount	249,000,000	225,000,000
Estimated Fair Value, Asset		1,000,000
Estimated Fair Value, (Liability)	(1,000,000)
Without Hedge Designation [Member] | Commodity Futures [Member] | Long [Member]
Derivative [Line Items]
Contractual/Notional Amount	$ 39,000,000	$ 42,000,000

Fair Value - Assets and Liabili

Fair Value - Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Payable to Brokers [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of liabilities, measured on a recurring basis	$ (9)	$ (44)
Corporate and Other Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	19,584	18,958
States, Municipalities and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	13,956	13,240
Residential Mortgage-Backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	5,005	5,073
Commercial Mortgage-Backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	1,900	2,040
Other Asset-Backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	1,061	1,025
Total Asset-Backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	7,966	8,138
U.S. Treasury and Obligations of Government-Sponsored Enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	115	93
Foreign Government [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	445	445
Redeemable Preferred Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	20	19
Total Fixed Maturities Available-for-Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	42,086	40,893
Fixed Maturities Trading [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	421	601
Fixed Maturity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	42,507	41,494
Equity Securities Available-for-Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	129	110
Equity Securities Trading [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	481	439
Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	610	549
Other Invested Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	66	60
Receivables [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis		1
Life Settlement Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis		58
Short Term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	4,895	4,686
Level 1 [Member] | Payable to Brokers [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of liabilities, measured on a recurring basis	(9)	(44)
Level 1 [Member] | U.S. Treasury and Obligations of Government-Sponsored Enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	115	93
Level 1 [Member] | Redeemable Preferred Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	20	19
Level 1 [Member] | Total Fixed Maturities Available-for-Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	135	112
Level 1 [Member] | Fixed Maturities Trading [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	9
Level 1 [Member] | Fixed Maturity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	144	112
Level 1 [Member] | Equity Securities Available-for-Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	110	91
Level 1 [Member] | Equity Securities Trading [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	479	438
Level 1 [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	589	529
Level 1 [Member] | Other Invested Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	61	55
Level 1 [Member] | Receivables [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis		1
Level 1 [Member] | Short Term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	4,019	3,833
Level 2 [Member] | Corporate and Other Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	19,465	18,828
Level 2 [Member] | States, Municipalities and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	13,955	13,239
Level 2 [Member] | Residential Mortgage-Backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	4,829	4,944
Level 2 [Member] | Commercial Mortgage-Backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	1,876	2,027
Level 2 [Member] | Other Asset-Backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	915	968
Level 2 [Member] | Total Asset-Backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	7,620	7,939
Level 2 [Member] | Foreign Government [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	445	445
Level 2 [Member] | Total Fixed Maturities Available-for-Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	41,485	40,451
Level 2 [Member] | Fixed Maturities Trading [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	407	595
Level 2 [Member] | Fixed Maturity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	41,892	41,046
Level 2 [Member] | Other Invested Assets [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	5	5
Level 2 [Member] | Short Term Investments [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	876	853
Level 3 [Member] | Corporate and Other Bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	119	130
Level 3 [Member] | States, Municipalities and Political Subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	1	1
Level 3 [Member] | Residential Mortgage-Backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	176	129
Level 3 [Member] | Commercial Mortgage-Backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	24	13
Level 3 [Member] | Other Asset-Backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	146	57
Level 3 [Member] | Total Asset-Backed [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	346	199
Level 3 [Member] | Total Fixed Maturities Available-for-Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	466	330
Level 3 [Member] | Fixed Maturities Trading [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	5	6
Level 3 [Member] | Fixed Maturity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	471	336
Level 3 [Member] | Equity Securities Available-for-Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	19	19
Level 3 [Member] | Equity Securities Trading [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	2	1
Level 3 [Member] | Equity Securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis	$ 21	20
Level 3 [Member] | Life Settlement Contracts [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of assets, measured on a recurring basis		$ 58

Fair Value - Reconciliations of

Fair Value - Reconciliations of Assets and Liabilities Measured at Fair Value on Recurring Basis Using Significant Unobservable Inputs (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Derivative Instruments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Derivative financial instruments, net, Beginning balance		$ 1		$ 3
Derivative financial instruments, net, Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in Net Income (Loss)		(1)	$ 1	(4)
Derivative financial instruments, net, Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in OCI		0	0	0
Derivative financial instruments, net, Purchases		0	0	0
Derivative financial instruments, net, Sales			(1)	(2)
Derivative financial instruments, net, Settlements		0	0	0
Derivative financial instruments, net, Transfers into Level 3				3
Derivative financial instruments, net, Transfers out of Level 3		0	0	0
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at June 30				(3)
Corporate and Other Bonds [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	$ 100	242	130	168
Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in Net Income (Loss)	1	1	1	1
Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in OCI	1	7	2	14
Purchases	13	16	18	163
Sales			(1)	(36)
Settlements	(11)	(5)	(36)	(15)
Transfers into Level 3	15		15
Transfers out of Level 3			(10)	(34)
Ending balance	119	261	119	261
States, Municipalities and Political Subdivisions [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	1	2	1	2
Settlements		(1)		(1)
Ending balance	1	1	1	1
Residential Mortgage-Backed [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	123	134	129	134
Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in Net Income (Loss)	1		3	2
Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in OCI	1	(1)	4	(2)
Purchases		5		15
Settlements	(7)	(1)	(18)	(10)
Transfers into Level 3	58		58
Transfers out of Level 3		(58)		(60)
Ending balance	176	79	176	79
Commercial Mortgage-Backed [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	13	11	13	22
Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in OCI	(1)		(1)
Purchases	12	23	12	32
Settlements	(2)	(8)	(2)	(17)
Transfers into Level 3	2		2	3
Transfers out of Level 3		(2)		(16)
Ending balance	24	24	24	24
Other Asset-Backed [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	82	45	57	53
Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in Net Income (Loss)	(1)		(2)
Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in OCI	1		1	2
Purchases	27	34	78	69
Sales				(25)
Settlements	(4)		(6)	(1)
Transfers into Level 3	41		93	2
Transfers out of Level 3		(36)	(75)	(57)
Ending balance	146	43	146	43
Total Asset-Backed [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	218	190	199	209
Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in Net Income (Loss)			1	2
Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in OCI	1	(1)	4
Purchases	39	62	90	116
Sales				(25)
Settlements	(13)	(9)	(26)	(28)
Transfers into Level 3	101		153	5
Transfers out of Level 3		(96)	(75)	(133)
Ending balance	346	146	346	146
Total Fixed Maturities Available-for-Sale [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	319	434	330	379
Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in Net Income (Loss)	1	1	2	3
Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in OCI	2	6	6	14
Purchases	52	78	108	279
Sales			(1)	(61)
Settlements	(24)	(15)	(62)	(44)
Transfers into Level 3	116		168	5
Transfers out of Level 3		(96)	(85)	(167)
Ending balance	466	408	466	408
Fixed Maturities Trading [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	5	6	6	85
Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in Net Income (Loss)			(1)	5
Purchases				2
Sales				(86)
Ending balance	5	6	5	6
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at June 30		(1)	(1)	3
Fixed Maturity Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	324	440	336	464
Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in Net Income (Loss)	1	1	1	8
Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in OCI	2	6	6	14
Purchases	52	78	108	281
Sales			(1)	(147)
Settlements	(24)	(15)	(62)	(44)
Transfers into Level 3	116		168	5
Transfers out of Level 3		(96)	(85)	(167)
Ending balance	471	414	471	414
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at June 30		(1)	(1)	3
Equity Securities Available-for-Sale [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	19	19	19	20
Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in Net Income (Loss)		(1)		(1)
Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in OCI		1	2
Purchases			1
Sales			(3)
Ending balance	19	19	19	19
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at June 30		(2)		(2)
Equity Securities Trading [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	1	2	1	1
Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in Net Income (Loss)				1
Purchases	1	(1)	1
Sales				(1)
Ending balance	2	1	2	1
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at June 30		(1)
Equity Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	20	21	20	21
Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in Net Income (Loss)		(1)
Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in OCI		1	2
Purchases	1	(1)	2
Sales			(3)	(1)
Ending balance	21	20	21	20
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at June 30		(3)		(2)
Life Settlement Contracts [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	1	67	58	74
Net Realized Gains (Losses) and Net Change in Unrealized Gains (Losses), Included in Net Income (Loss)			6	10
Sales	$ (1)		(59)
Settlements			$ (5)	(17)
Ending balance		$ 67		67
Unrealized Gains (Losses) Recognized in Net Income (Loss) on Level 3 Assets and Liabilities Held at June 30				$ 2

Fair Value - Additional Informa

Fair Value - Additional Information (Detail) - USD ($)	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016	Sep. 30, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Transfers out of Level 1 to Level 2, Assets	$ 0		$ 0
CNA Financial [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Notes receivable maturity period	3 years
Note receivable	$ 45,000,000
Investments in life settlement contracts	$ 0	$ 58,000,000

Fair Value - Quantitative Infor

Fair Value - Quantitative Information about Significant Unobservable Inputs Utilized by Company in Fair Value Measurements of Level 3 Assets (Detail) - Fixed Maturity Securities [Member] - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Discounted Cash Flow [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Estimated Fair Value	$ 139	$ 106
Valuation Techniques	Discounted cash flow
Minimum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit spread adjustment	1.00%	2.00%
Maximum [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit spread adjustment	12.00%	40.00%
Weighted Average [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Credit spread adjustment	3.00%	4.00%

Fair Value - Carrying Amount, E

Fair Value - Carrying Amount, Estimated Fair Value and Level of Fair Value Hierarchy of Company's Financial Assets and Liabilities (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Estimate Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other invested assets, primarily mortgage loans	$ 731	$ 594
Short term debt	193	107
Long term debt	11,532	10,796
Carrying Amount [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other invested assets, primarily mortgage loans	722	591
Short term debt	191	107
Long term debt	11,222	10,655
Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Short term debt	152	104
Long term debt	10,316	10,150
Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Other invested assets, primarily mortgage loans	731	594
Short term debt	41	3
Long term debt	$ 1,216	$ 646

Property, Plant and Equipment -

Property, Plant and Equipment - Additional Information (Detail) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	May 31, 2017USD ($)	Sep. 30, 2017Rig	Jun. 30, 2017USD ($)Rig	Sep. 30, 2016USD ($)
Diamond Offshore [Member]
Property, Plant and Equipment [Line Items]
Asset impairment charge, before tax and noncontrolling interests			$ 72	$ 672
Asset impairment charge, net of tax and noncontrolling interests			$ 23	$ 263
Diamond Offshore [Member] | Drilling Rigs [Member]
Property, Plant and Equipment [Line Items]
Number of rigs evaluated for impairment | Rig		6	7
Diamond Offshore [Member] | Ultra Deepwater [Member]
Property, Plant and Equipment [Line Items]
Number of rigs impaired | Rig			1
Diamond Offshore [Member] | Deepwater Semisubmersible Rigs [Member]
Property, Plant and Equipment [Line Items]
Number of rigs impaired | Rig			1
Boardwalk Pipeline [Member]
Property, Plant and Equipment [Line Items]
Proceed from sale of plant and equipment	$ 64
Gain (loss) on sale of plant and equipment	(47)
Gain (loss) on sale of plant and equipment,net of tax and noncontrolling interests	$ (15)

Claim and Claim Adjustment Ex46

Claim and Claim Adjustment Expense Reserves - Additional Information (Detail) - CNA Financial [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2010	Dec. 31, 2016
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Catastrophe losses, net of reinsurance	$ 269	$ 16	$ 342	$ 137
Catastrophe-related reinsurance reinstatement premium	6		6
Net A&EP adverse development before consideration of LPT			60	$ 200
Fair value of the collateral trust account	2,900		2,900			$ 2,800
Hurricane Harvey [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Catastrophe losses, net of reinsurance	149		149
Hurricane Irma [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Catastrophe losses, net of reinsurance	95		95
Hurricane Maria [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Catastrophe losses, net of reinsurance	20		20
Asbestos and Environmental Pollution Reserves [Member]
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Net A&EP claim and allocated claim adjustment expense reserves					$ 1,600
Aggregate limit under A&EP Loss Portfolio Transfer					4,000
Ceded A&EP claim and allocated claim adjustment expense reserves					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					$ 2,200
Cumulative amounts ceded under the Loss Portfolio Transfer	2,900		2,900			2,800
Remaining unrecognized retroactive reinsurance benefit	$ 334		$ 334			$ 334

Claim and Claim Adjustment Ex47

Claim and Claim Adjustment Expense Reserves - Reconciliation of Claim and Claim Adjustment Expense Reserves (Detail) - CNA Financial [Member] - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Liability for Claims and Claims Adjustment Expense [Line Items]
Gross reserves, beginning of year	$ 22,343	$ 22,663
Ceded reserves, beginning of year	4,094	4,087
Net reserves, beginning of year	18,249	18,576
Net incurred claim and claim adjustment expenses:
Provision for insured events of current year	3,949	3,799
Decrease in provision for insured events of prior years	(284)	(332)
Amortization of discount	138	134
Total net incurred	3,803	3,601
Net payments attributable to:
Current year events	(560)	(591)
Prior year events	(3,401)	(3,209)
Total net payments	(3,961)	(3,800)
Foreign currency translation adjustment and other	110	39
Net reserves, end of period	18,201	18,416
Ceded reserves, end of period	4,008	4,256
Gross reserves, end of period	$ 22,209	$ 22,672

Claim and Claim Adjustment Ex48

Claim and Claim Adjustment Expense Reserves - Net Prior Year Development (Detail) - CNA Financial [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Pretax (favorable) unfavorable net prior year claim and allocated claim adjustment expense reserve development	$ (115)	$ (132)	$ (227)	$ (282)
Pretax (favorable) unfavorable premium development	(19)	(5)	(2)	(27)
Total pretax (favorable) unfavorable net prior year development	$ (134)	$ (137)	$ (229)	$ (309)

Claim and Claim Adjustment Ex49

Claim and Claim Adjustment Expense Reserves - Net Prior Year Claim and Allocated Claim Adjustment Expense Reserve Development (Detail) - CNA Financial [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Causes of Increase (Decrease) in Liability for Unpaid Claims and Claims Adjustment Expense [Line Items]
Medical professional liability	$ 1	$ 13	$ 5	$ (17)
Other professional liability and management liability	(27)	(48)	(96)	(98)
Surety	(82)	(63)	(82)	(63)
Commercial auto	(14)	(12)	(40)	(47)
General liability	7	14	6	(38)
Workers' compensation	7	(6)	(39)	48
Other	(7)	(30)	19	(67)
Total pretax (favorable) unfavorable development	$ (115)	$ (132)	$ (227)	$ (282)

Claim and Claim Adjustment Ex50

Claim and Claim Adjustment Expense Reserves - Schedule of Impact of Loss Portfolio Transfer on the Consolidated Statement of Operations (Detail) - CNA Financial [Member] - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Claim And Claim Adjustment Expense Reserves [Line Items]
Net A&EP adverse development before consideration of LPT			$ 60	$ 200
Retroactive reinsurance benefit recognized	$ (17)	$ (12)	$ (60)	(94)
Pretax impact of A&EP reserve development and the LPT	$ (17)	$ (12)		$ 106

Debt - Additional Information (

Debt - Additional Information (Detail) - USD ($)	3 Months Ended			9 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Sep. 30, 2017
CNA Financial [Member] | 3.5% Senior Notes Due August 15, 2027 [Member]
Debt Instrument [Line Items]
Debt instrument principal amount	$ 500,000,000			$ 500,000,000
Debt instrument interest rate	3.50%			3.50%
Debt maturity date	Aug. 15, 2027
CNA Financial [Member] | 7.4% Senior Notes Due November 15, 2019 [Member]
Debt Instrument [Line Items]
Debt instrument principal amount	$ 350,000,000			$ 350,000,000
Debt instrument interest rate	7.40%			7.40%
Debt maturity date	Nov. 15, 2019
Early extinguishment of debt, loss	$ 42,000,000			$ 42,000,000
Early extinguishment of debt, loss net of tax and noncontrolling interests	24,000,000			24,000,000
CNA Financial [Member] | 7.4% Senior Notes Due November 15, 2019 [Member] | Interest Expense [Member]
Debt Instrument [Line Items]
Early extinguishment of debt	350,000,000			350,000,000
Diamond Offshore [Member] | 7.9% Senior Notes Due August 15, 2025 [Member]
Debt Instrument [Line Items]
Debt instrument principal amount	$ 500,000,000			$ 500,000,000
Debt instrument interest rate	7.90%			7.90%
Debt maturity date	Aug. 15, 2025
Diamond Offshore [Member] | 5.9% Senior Notes Due May 1, 2019 [Member]
Debt Instrument [Line Items]
Debt instrument principal amount	$ 500,000,000			$ 500,000,000
Debt instrument interest rate	5.90%			5.90%
Debt maturity date	May 1, 2019
Early extinguishment of debt, loss	$ 35,000,000			$ 35,000,000
Early extinguishment of debt, loss net of tax and noncontrolling interests	11,000,000			11,000,000
Diamond Offshore [Member] | 5.9% Senior Notes Due May 1, 2019 [Member] | Interest Expense [Member]
Debt Instrument [Line Items]
Early extinguishment of debt	500,000,000			500,000,000
Boardwalk Pipeline [Member] | 4.5% Senior Notes Due July 15, 2027 [Member]
Debt Instrument [Line Items]
Debt instrument principal amount			$ 500,000,000
Debt instrument interest rate			4.50%
Debt maturity date			Jul. 15, 2027
Boardwalk Pipeline [Member] | 6.3% Senior Notes Due August 15, 2017 [Member]
Debt Instrument [Line Items]
Debt instrument principal amount			$ 275,000,000
Debt instrument interest rate			6.30%
Debt maturity date			Aug. 15, 2017
Consolidated Container Company [Member] | Interest Rate Swaps [Member]
Debt Instrument [Line Items]
Interest rate swaps for notional amount		$ 500,000,000
Percentage of interest on hedged portion of term loan		5.60%
Consolidated Container Company [Member] | Credit Agreement [Member]
Debt Instrument [Line Items]
Debt issuance costs		$ 19,000,000
Consolidated Container Company [Member] | Credit Agreement [Member] | Loans Payable [Member]
Debt Instrument [Line Items]
Debt instrument principal amount		$ 605,000,000
Debt maturity date		May 22, 2024
Annual principal amortization of loan		1.00%
Consolidated Container Company [Member] | Credit Agreement [Member] | Loans Payable [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt instrument LIBOR applicable margin		3.50%
Consolidated Container Company [Member] | Credit Agreement [Member] | Loans Payable [Member] | London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member]
Debt Instrument [Line Items]
Debt instrument interest rate		1.00%
Consolidated Container Company [Member] | Credit Agreement [Member] | ABL Facility [Member]
Debt Instrument [Line Items]
Credit agreement period		5 years
Line of credit borrowing amount		$ 125,000,000
Borrowings outstanding amount	$ 0			$ 0

Shareholders' Equity - Componen

Shareholders' Equity - Components of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ 23,361	$ 22,810
Other comprehensive income	$ 77	$ 29	285	562
Ending Balance	24,361	23,406	24,361	23,406
OTTI Gains (Losses) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	23	28	27	24
Other comprehensive income (loss) before reclassifications, after tax	1	7		9
Reclassification of (gains) losses from accumulated other comprehensive income, after tax		(4)	(3)	(2)
Other comprehensive income	1	3	(3)	7
Amounts attributable to noncontrolling interests		(1)		(1)
Ending Balance	24	30	24	30
Unrealized Gains (Losses) on Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	705	838	576	347
Other comprehensive income (loss) before reclassifications, after tax	35	69	228	608
Reclassification of (gains) losses from accumulated other comprehensive income, after tax	(12)	(27)	(61)	(17)
Other comprehensive income	23	42	167	591
Amounts attributable to noncontrolling interests	(3)	(4)	(18)	(62)
Ending Balance	725	876	725	876
Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(2)	(2)	(2)	(3)
Other comprehensive income (loss) before reclassifications, after tax	(2)		(3)
Reclassification of (gains) losses from accumulated other comprehensive income, after tax	3	1	4	2
Other comprehensive income	1	1	1	2
Amounts attributable to noncontrolling interests	(1)	(1)	(1)	(1)
Ending Balance	(2)	(2)	(2)	(2)
Pension Liability [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(632)	(639)	(646)	(649)
Reclassification of (gains) losses from accumulated other comprehensive income, after tax	11	7	26	20
Other comprehensive income	11	7	26	20
Amounts attributable to noncontrolling interests	(1)		(2)	(3)
Ending Balance	(622)	(632)	(622)	(632)
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(130)	(106)	(178)	(76)
Other comprehensive income (loss) before reclassifications, after tax	41	(24)	94	(58)
Other comprehensive income	41	(24)	94	(58)
Amounts attributable to noncontrolling interests	(4)	2	(9)	6
Ending Balance	(93)	(128)	(93)	(128)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(36)	119	(223)	(357)
Other comprehensive income (loss) before reclassifications, after tax	75	52	319	559
Reclassification of (gains) losses from accumulated other comprehensive income, after tax	2	(23)	(34)	3
Other comprehensive income	77	29	285	562
Amounts attributable to noncontrolling interests	(9)	(4)	(30)	(61)
Ending Balance	$ 32	$ 144	$ 32	$ 144

Shareholders' Equity - Compon53

Shareholders' Equity - Components of Accumulated Other Comprehensive Income (Parenthetical) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
OTTI Gains (Losses) [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax on change in other comprehensive income (loss) before reclassifications	$ 0	$ (4)	$ 0	$ (5)
Tax on reclassification from accumulated other comprehensive income	0	2	1	1
Unrealized Gains (Losses) on Investments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax on change in other comprehensive income (loss) before reclassifications	(20)	(32)	(130)	(304)
Tax on reclassification from accumulated other comprehensive income	4	13	28	12
Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax on change in other comprehensive income (loss) before reclassifications	0	0	0	0
Tax on reclassification from accumulated other comprehensive income	0	0	0	0
Pension Liability [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax on change in other comprehensive income (loss) before reclassifications	0	0	0	0
Tax on reclassification from accumulated other comprehensive income	(6)	(4)	(13)	(11)
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Tax on change in other comprehensive income (loss) before reclassifications	0	0	0	0
Tax on reclassification from accumulated other comprehensive income	$ 0	$ 0	$ 0	$ 0

Shareholders' Equity - Addition

Shareholders' Equity - Additional Information (Detail) - USD ($) shares in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Equity [Abstract]
Treasury stock repurchased, shares	0.1	3
Purchase of Loews treasury stock	$ 6	$ 115

Benefit Plans - Components of N

Benefit Plans - Components of Net Periodic Benefit Cost (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 2	$ 2	$ 6	$ 6
Interest cost	30	33	89	97
Expected return on plan assets	(43)	(45)	(129)	(133)
Amortization of unrecognized net loss	10	11	32	34
Settlement charge	7	1	10	3
Net periodic benefit cost	6	2	8	7
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Service cost		1		1
Interest cost	1	1	2	2
Expected return on plan assets	(1)	(1)	(3)	(3)
Amortization of unrecognized prior service benefit	(1)	$ (1)	(2)	(3)
Net periodic benefit cost	$ (1)		$ (3)	$ (3)

Commitments and Contingencies -

Commitments and Contingencies - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017	Dec. 31, 2016
Commitments [Line Items]
Future policy benefits	$ 11,040	$ 11,040	$ 10,326
CNA Financial [Member]
Commitments [Line Items]
Aggregate amount related to indemnification agreements	254	254
Aggregate amount related to quantifiable guarantees	375	375
Potential amount of future payments under guarantees	1,800	1,800
Increase (decrease) in premium development recognized	0	(37)
Decrease in pretax income	1	7
CNA Financial [Member] | Workers Compensation Policy [Member]
Commitments [Line Items]
Future policy benefits	$ 61	$ 61

Segments - Additional Informati

Segments - Additional Information (Detail)	9 Months Ended
	Sep. 30, 2017Segment
Segment Reporting [Abstract]
Number of reportable segments	5
Number of individual operating subsidiaries	4

Segments - Consolidating Statem

Segments - Consolidating Statement of Income by Segment (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues:
Insurance premiums	$ 1,806	$ 1,767	$ 5,185	$ 5,196
Net investment income	557	561	1,639	1,570
Investment gains (losses)	16	45	93	18
Contract drilling revenues	357	340	1,113	1,141
Other revenues	785	574	2,150	1,842
Total	3,521	3,287	10,180	9,767
Expenses:
Insurance claims and policyholders' benefits	1,480	1,202	4,053	3,949
Amortization of deferred acquisition costs	309	314	926	926
Contract drilling expenses	198	187	598	598
Other operating expenses	1,047	898	2,978	3,416
Interest	223	130	504	403
Total	3,257	2,731	9,059	9,292
Income (loss) before income tax	264	556	1,121	475
Income tax (expense) benefit	(52)	(163)	(240)	(171)
Net income (loss)	212	393	881	304
Amounts attributable to noncontrolling interests	(55)	(66)	(198)	60
Net income (loss) attributable to Loews Corporation	157	327	683	364
CNA Financial [Member] | Operating Segments [Member]
Revenues:
Insurance premiums	1,806	1,767	5,185	5,196
Net investment income	509	524	1,529	1,461
Investment gains (losses)	16	45	93	30
Other revenues	110	97	329	297
Total	2,441	2,433	7,136	6,984
Expenses:
Insurance claims and policyholders' benefits	1,480	1,202	4,053	3,949
Amortization of deferred acquisition costs	309	314	926	926
Other operating expenses	379	402	1,086	1,158
Interest	83	39	166	127
Total	2,251	1,957	6,231	6,160
Income (loss) before income tax	190	476	905	824
Income tax (expense) benefit	(44)	(132)	(226)	(203)
Net income (loss)	146	344	679	621
Amounts attributable to noncontrolling interests	(16)	(36)	(71)	(64)
Net income (loss) attributable to Loews Corporation	130	308	608	557
Diamond Offshore [Member] | Operating Segments [Member]
Revenues:
Net investment income		1	1	1
Investment gains (losses)				(12)
Contract drilling revenues	357	340	1,113	1,141
Other revenues	11	9	30	69
Total	368	350	1,144	1,199
Expenses:
Contract drilling expenses	198	187	598	598
Other operating expenses	109	108	414	1,082
Interest	64	19	119	69
Total	371	314	1,131	1,749
Income (loss) before income tax	(3)	36	13	(550)
Income tax (expense) benefit	14	(22)	35	78
Net income (loss)	11	14	48	(472)
Amounts attributable to noncontrolling interests	(5)	(7)	(23)	228
Net income (loss) attributable to Loews Corporation	6	7	25	(244)
Boardwalk Pipeline [Member] | Operating Segments [Member]
Revenues:
Other revenues	301	306	987	961
Total	301	306	987	961
Expenses:
Other operating expenses	191	212	646	615
Interest	41	48	131	136
Total	232	260	777	751
Income (loss) before income tax	69	46	210	210
Income tax (expense) benefit	(18)	(9)	(46)	(44)
Net income (loss)	51	37	164	166
Amounts attributable to noncontrolling interests	(34)	(23)	(104)	(104)
Net income (loss) attributable to Loews Corporation	17	14	60	62
Loews Hotels And Co [Member] | Operating Segments [Member]
Revenues:
Other revenues	162	161	510	513
Total	162	161	510	513
Expenses:
Other operating expenses	147	151	443	479
Interest	7	6	20	17
Total	154	157	463	496
Income (loss) before income tax	8	4	47	17
Income tax (expense) benefit	(4)	(1)	(23)	(10)
Net income (loss)	4	3	24	7
Net income (loss) attributable to Loews Corporation	4	3	24	7
Corporate [Member]
Revenues:
Net investment income	48	36	109	108
Other revenues	201	1	294	2
Total	249	37	403	110
Expenses:
Other operating expenses	221	25	389	82
Interest	28	18	68	54
Total	$ 249	43	457	136
Income (loss) before income tax		(6)	(54)	(26)
Income tax (expense) benefit		1	20	8
Net income (loss)		(5)	(34)	(18)
Net income (loss) attributable to Loews Corporation		$ (5)	$ (34)	$ (18)