Chubb Limited (CB) 10-Q 1 Nov 17 2017 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - SFr / shares	9 Months Ended
	Sep. 30, 2017	Oct. 20, 2017	Dec. 31, 2016
Entity Information [Line Items]
Common Shares, par value	SFr 24.15		SFr 24.15
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	CB
Entity Registrant Name	Chubb Ltd
Entity Central Index Key	896,159
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Common Shares Outstanding		464,221,986

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions		Sep. 30, 2017		Dec. 31, 2016
Assets
Fixed maturities available for sale, at fair value (amortized cost – $82,254 and $79,536)(includes hybrid financial instruments of nil and $2)		$ 83,686		$ 80,115
Fixed maturities held to maturity, at amortized cost (fair value – $10,365 and $10,670)		10,160		10,644
Equity securities, at fair value (cost – $723 and $706)		910		814
Short-term investments, at fair value and amortized cost		2,991		3,002
Other investments (cost – $4,429 and $4,270)		4,677		4,519
Total investments		102,424		99,094
Cash	[1]	1,088	[2]	985	[3]
Securities lending collateral		1,757		1,092
Accrued investment income		911		918
Insurance and reinsurance balances receivable		9,551		8,970
Reinsurance recoverable on losses and loss expenses		14,799		13,577
Reinsurance recoverable on policy benefits		193		182
Deferred policy acquisition costs		4,691		4,314
Value of business acquired		339		355
Goodwill		15,707		15,332
Other intangible assets		6,558		6,763
Prepaid reinsurance premiums		2,506		2,448
Investments in partially-owned insurance companies		652		666
Other assets		6,402		5,090
Total assets		167,578		159,786
Liabilities
Unpaid losses and loss expenses		64,153		60,540
Unearned premiums		15,456		14,779
Future policy benefits		5,307		5,036
Insurance and reinsurance balances payable		5,827		5,637
Securities lending payable		1,757		1,093
Accounts payable, accrued expenses, and other liabilities		9,173		8,617
Deferred tax liabilities		1,139		988
Repurchase agreements		1,408		1,403
Short-term debt		1,020		500
Long-term debt		11,559		12,610
Trust preferred securities		308		308
Total liabilities		117,107		111,511
Commitments and contingencies
Shareholders’ equity
Common Shares (CHF 24.15 par value; 479,783,864 shares issued; 464,158,519 and 465,968,716 shares outstanding)		11,121		11,121
Common Shares in treasury (15,625,345 and 13,815,148 shares)		(1,877)		(1,480)
Additional Paid in Capital, Common Stock		14,217		15,335
Retained earnings		25,941		23,613
Accumulated other comprehensive income (loss) (AOCI)		1,069		(314)
Total shareholders’ equity		50,471		48,275
Total liabilities and shareholders’ equity		$ 167,578		$ 159,786
[1]	Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At September 30, 2017 and December 31, 2016, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[2]	Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At September 30, 2017, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[3]	Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At December 31, 2016, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) $ in Millions	Sep. 30, 2017USD ($)shares	Dec. 31, 2016USD ($)shares
Statement of Financial Position [Abstract]
Available for sale, at amortized cost	$ 82,254	$ 79,536
Fixed maturities available for sale, hybrid financial instruments	0	2
Held to maturity, at Fair Value	10,365	10,670
Equity securities, at cost	723	706
Other investments, cost	$ 4,429	$ 4,270
Common Shares, shares issued | shares	479,783,864	479,783,864
Common Shares, shares outstanding | shares	464,158,519	465,968,716
Common Shares in treasury, shares | shares	15,625,345	13,815,148

Consolidated Statements Of Oper

Consolidated Statements Of Operations and Comprehensive Income - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Revenues
Net premiums written	$ 7,902	$ 7,573	$ 22,193	$ 21,207
Decrease (increase) in unearned premiums	(95)	115	(377)	483
Net premiums earned	7,807	7,688	21,816	21,690
Net investment income	813	739	2,328	2,121
Net Realized Gains Losses [Abstract]
Other-than-temporary impairment (OTTI) losses gross	(8)	(12)	(36)	(99)
Portion of OTTI losses recognized in other comprehensive income (OCI)	0	0	1	8
Net OTTI losses recognized in income	(8)	(12)	(35)	(91)
Net realized gains (losses) excluding OTTI losses	(2)	112	119	(419)
Total net realized gains (losses) (includes $10, $33, $27, and $(117) reclassified from AOCI)	(10)	100	84	(510)
Total revenues	8,610	8,527	24,228	23,301
Expenses
Losses and loss expenses	6,247	4,269	14,182	12,197
Policy benefits	169	155	500	427
Policy acquisition costs	1,488	1,514	4,334	4,487
Administrative expenses	714	772	2,096	2,373
Interest expense	150	152	451	451
Other (income) expense	(118)	(91)	(333)	(92)
Amortization of purchased intangibles	65	4	194	16
Chubb integration expenses	50	115	233	361
Total expenses	8,765	6,890	21,657	20,220
Loss before income tax	(155)	1,637	2,571	3,081
Income tax expense (benefit) (includes nil, $11, $3 and $16 on reclassified unrealized gains and losses)	(85)	277	243	556
Net income (loss)	(70)	1,360	2,328	2,525
Other comprehensive income
Unrealized appreciation	153	247	919	2,099
Reclassification adjustment for net realized (gains) losses included in net income (loss)	(10)	(33)	(27)	117
Unrealized appreciation (Depreciation) after reclassification adjustment	143	214	892	2,216
Change in:
Cumulative foreign currency translation adjustment	665	(124)	901	269
Postretirement benefit liability adjustment	(63)	5	(118)	8
Other comprehensive income, before income tax	745	95	1,675	2,493
Income tax expense related to OCI items	(46)	(79)	(292)	(561)
Other comprehensive income	699	16	1,383	1,932
Comprehensive income	$ 629	$ 1,376	$ 3,711	$ 4,457
Earnings (loss) per share
Basic earnings (loss) per share	$ (0.15)	$ 2.90	$ 4.98	$ 5.48
Diluted earnings (loss) per share	$ (0.15)	$ 2.88	$ 4.94	$ 5.44

Consolidated Statements Of Ope5

Consolidated Statements Of Operations and Comprehensive Income Consolidated Statements of Operations and Comprehensive Income (Parenthetical) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Total net realized gains (losses) reclassified from AOCI	$ 10	$ 33	$ 27	$ (117)
Income tax expense on reclassified unrealized gains and loses	$ 0	$ 11	$ 3	$ 16

Consolidated Statements Of Shar

Consolidated Statements Of Shareholders' Equity - USD ($) $ in Millions	Total	Common Stock [Member]	Common Stock [Member]The Chubb Corporation [Member]	Common shares in treasury [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member]The Chubb Corporation [Member]	Retained Earnings [Member]	Accumulated Net Unrealized Investment Gain (Loss) [Member]	Cumulative Foreign Currency Translation Adjustment [Member]	Postretirement Benefit Liability Adjustment [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
Balance - beginning of period at Dec. 31, 2015		$ 7,833		$ (1,922)	$ 4,481		$ 19,478	$ 874	$ (1,539)	$ (70)
Shares Issued for Chubb Corp Acquisition			$ 3,288			$ 11,916
Common Shares repurchased				0
Net shares redeemed under employee share-based compensation plans				372	(365)	323
Exercise of stock options					(44)
Share-based compensation expense and other					250
Funding of dividends declared to Retained earnings					(960)
Net income	$ 2,525						2,525
Funding of dividends declared from Additional paid-in capital							960
Dividends declared on Common Shares							(960)
Change in period, before reclassification from AOCI, net of income tax expense of $(310) and $(559)								1,540
Amounts reclassified from AOCI, net of income tax benefit of $3 and $16								133
Change in period, net of income tax expense of $(307) and $(543)								1,673
Change in period, net of income tax expense of $(14) and $(18)									251
Change in period, net of income tax benefit of $29 and nil										8
Balance - end of period at Sep. 30, 2016	48,372	11,121		(1,550)	15,601		22,003	2,547	(1,288)	(62)	$ 1,197
Balance - beginning of period at Dec. 31, 2016	48,275	11,121		(1,480)	15,335		23,613	1,058	(1,663)	291
Shares Issued for Chubb Corp Acquisition			$ 0			0
Common Shares repurchased				(707)
Net shares redeemed under employee share-based compensation plans				310	(311)	$ 0
Exercise of stock options					(43)
Share-based compensation expense and other					223
Funding of dividends declared to Retained earnings					(987)
Net income	2,328						2,328
Funding of dividends declared from Additional paid-in capital							987
Dividends declared on Common Shares							(987)
Change in period, before reclassification from AOCI, net of income tax expense of $(310) and $(559)								609
Amounts reclassified from AOCI, net of income tax benefit of $3 and $16								(24)
Change in period, net of income tax expense of $(307) and $(543)								585
Change in period, net of income tax expense of $(14) and $(18)									887
Change in period, net of income tax benefit of $29 and nil										(89)
Balance - end of period at Sep. 30, 2017	$ 50,471	$ 11,121		$ (1,877)	$ 14,217		$ 25,941	$ 1,643	$ (776)	$ 202	$ 1,069

Consolidated Statements Of Sha7

Consolidated Statements Of Shareholders' Equity (Parenthetical) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Statement Consolidated Statements Of Shareholders Equity [Abstract]
Change in year, before reclassification from AOCI, net of income tax benefit(expense)	$ (310)	$ (559)
Income tax benefit (expense) from reclassification of unrealized gains	3	16
Net unrealized appreciation on investments, Change in period, income tax (expense) benefit	(307)	(543)
Cumulative translation adjustment, Change in period, income tax(expense) benefit	(14)	(18)
Net income	2,328	2,525
Pension liability adjustment, Change in period, income tax (expense) benefit	$ 29	$ 0

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017		Sep. 30, 2016
Cash flows from operating activities
Net income	$ 2,328		$ 2,525
Adjustments to reconcile net income to net cash flows from operating activities
Net realized (gains) losses	(84)		510
Amortization of premiums/discounts on fixed maturities	526		558
Amortization of UPR related to the Chubb Corp acquisition	0		1,415
Deferred income taxes	(151)		(13)
Unpaid losses and loss expenses	2,789		916
Unearned premiums	340		(547)
Future policy benefits	186		129
Insurance and reinsurance balances payable	247		149
Accounts payable, accrued expenses, and other liabilities	(828)		(109)
Income taxes payable	(262)		308
Insurance and reinsurance balances receivable	(339)		(201)
Reinsurance recoverable on losses and loss expenses	(976)		(241)
Reinsurance recoverable on policy benefits	(10)		(6)
Deferred policy acquisition costs	(256)		(1,316)
Prepaid reinsurance premiums	(14)		33
Other	(85)		(273)
Net cash flows from operating activities	3,411		3,837
Cash flows from investing activities
Purchases of fixed maturities available for sale	(18,478)		(23,837)
Purchases of fixed maturities held to maturity	(262)		(189)
Purchases of equity securities	(125)		(100)
Sales of fixed maturities available for sale	9,215		13,863
Sales of equity securities	152		963
Maturities and redemptions of fixed maturities available for sale	7,699		6,936
Maturities and redemptions of fixed maturities held to maturity	644		627
Net change in short-term investments	44		11,866
Net derivative instruments settlements	(170)		(181)
Acquisition of subsidiaries (net of cash acquired of nil and $71)	0		(14,248)
Other	(62)		26
Net cash flows used for investing activities	(1,343)		(4,274)
Cash flows from financing activities
Dividends paid on Common Shares	(978)		(851)
Common Shares repurchased	(707)		0
Repayment of long-term debt	(500)		0
Proceeds from issuance of repurchase agreements	1,798		1,457
Repayment of repurchase agreements	(1,793)		(1,455)
Proceeds from share-based compensation plans	109		117
Policyholder contract deposits	312		473
Policyholder contract withdrawals	(211)		(247)
Other	0		(4)
Net cash flows used for financing activities	(1,970)		(510)
Effect of foreign currency rate changes on cash and cash equivalents	5		42
Net increase (decrease) in cash	103		(905)
Cash – beginning of period	985	[1],[2]	1,775	[3]
Cash – end of period	1,088	[2],[4]	870	[3]
Supplemental cash flow information
Taxes paid	652		360
Interest paid	$ 404		$ 390
[1]	Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At December 31, 2016, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[2]	Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At September 30, 2017 and December 31, 2016, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[3]	Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At September 30, 2016 and December 31, 2015, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[4]	Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At September 30, 2017, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

Consolidated Statements of Cas9

Consolidated Statements of Cash Flows (Parentheticals) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Statement of Cash Flows [Abstract]
Cash Acquired from Acquisition	$ 0	$ 71

General

General	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	General a) Basis of presentation Chubb Limited is a holding company incorporated in Zurich, Switzerland. Chubb Limited, through its subsidiaries, provides a broad range of insurance and reinsurance products to insureds worldwide. Chubb operates through the following business segments: North America Commercial P&C Insurance, North America Personal P&C Insurance, North America Agricultural Insurance, Overseas General Insurance, Global Reinsurance, and Life Insurance. Refer to Note 10 for additional information. The interim unaudited consolidated financial statements, which include the accounts of Chubb Limited and its subsidiaries (collectively, Chubb, we, us, or our), have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) and, in the opinion of management, reflect all adjustments (consisting of normally recurring accruals) necessary for a fair statement of the results and financial position for such periods. All significant intercompany accounts and transactions, including internal reinsurance transactions, have been eliminated. The results of operations and cash flows for any interim period are not necessarily indicative of the results for the full year. These consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes included in our 2016 Form 10-K. b) Goodwill During the nine months ended September 30, 2017, Goodwill increased $ 375 million , primarily reflecting the impact of foreign exchange. c) Debt In February 2017, Chubb INA Holdings Inc.’s $ 500 million of 5.7 percent senior notes matured and were fully paid. In 2017, we reclassified $ 300 million of the 5.8 percent senior notes ( $300 million par value due to mature in March 2018), $ 616 million of the 5.75 percent senior notes ( $600 million par value due to mature in May 2018), and $ 104 million of the 6.6 percent senior notes ( $100 million par value due to mature in August 2018), from Long-term debt to Short-term debt in the Consolidated balance sheets. Effective April 15, 2017, the interest rate on our $ 1.0 billion of unsecured junior subordinated capital securities converted to a floating rate, equal to the three-month LIBOR plus 2.25 percentage points. Previously, these capital securities carried interest at a rate of 6.375 percent. The current interest rate, at the time of this filing, on these securities is 3.61 percent. The scheduled maturity date for these securities is April 15, 2037. d) Accounting guidance adopted in 2017 Stock Compensation Effective January 2017, we prospectively adopted new guidance on stock compensation which requires recognition of the excess tax benefits or deficiencies of share-based compensation awards to employees through net income rather than through additional paid in capital. The calculation of the excess tax benefits or deficiencies is based on the difference between the market value of a stock award at the date of vesting, or at the time of exercise for a stock option, compared to the grant date fair value recognized as compensation expense in the Consolidated statements of operations. For the three and nine months ended September 30, 2017, the excess tax benefit recorded to Income tax expense in the Consolidated statement of operations was $ 14 million and $44 million , respectively. Additionally, the guidance allowed for an election to account for forfeitures related to share-based payments either as they occur or through an estimation method. We elected to retain our current accounting for compensation expense using a forfeiture estimation process. e) Accounting guidance not yet adopted Goodwill Impairment In January 2017, the FASB issued updated guidance on goodwill impairment testing that eliminates Step 2 of the goodwill impairment test requiring entities to calculate the implied fair value of goodwill through a hypothetical purchase price allocation. Under the updated guidance, impairment will now be recognized as the amount by which a reporting unit’s carrying value exceeds its fair value. The standard will be effective for us in the first quarter of 2020 on a prospective basis with early adoption permitted. We do not expect the adoption of this guidance to have a material effect on our financial condition and results of operations. Premium Amortization on Purchased Callable Debt Securities In March 2017, the FASB issued guidance on the amortization period for purchased callable debt securities held at a premium. The guidance requires the premium to be amortized to the earliest call date. Under current guidance, premiums generally are amortized over the contracted life of the security. This guidance is effective for us in the first quarter of 2019 on a modified retrospective basis through a cumulative effect adjustment to beginning retained earnings. Early adoption is permitted. Securities held at a discount do not require an accounting change. We are in the process of evaluating the effect the updated guidance will have on our financial condition and results of operations. Refer to the 2016 Form 10-K for information on other accounting guidance not yet adopted.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2017
Business Combinations [Abstract]
Acquisitions	Acquisition The Chubb Corporation (Chubb Corp) On January 14, 2016, we completed the acquisition of Chubb Corp, a leading provider of middle-market commercial, specialty, surety, and personal insurance for $29.5 billion , comprising $14.3 billion in cash and $15.2 billion in newly-issued stock. In addition, we assumed outstanding equity awards to employees and directors with an attributed value of $323 million . The total consideration, including the assumption of equity awards, was $29.8 billion . We recognized goodwill of $ 10.5 billion , attributable to expected growth and profitability, none of which is expected to be deductible for income tax purposes. Refer to the 2016 Form 10-K for additional information on this acquisition. The consolidated financial statements include the results of Chubb Corp from the acquisition date. The following table summarizes the results of the acquired Chubb Corp operations within our 2016 Consolidated statements of operations for the periods presented: (in millions of U.S. dollars) Three Months Ended September 30, 2016 January 14, 2016 to September 30, 2016 Total revenues $ 2,656 $ 7,888 Net income $ 483 $ 1,064 The following table provides supplemental unaudited pro forma consolidated information for the three and nine months ended September 30, 2016 , as if Chubb Corp had been acquired as of January 1, 2015. The unaudited pro forma consolidated financial statements are presented solely for informational purposes and are not necessarily indicative of the consolidated results of operations that might have been achieved had the transaction been completed as of the date indicated, nor are they meant to be indicative of any anticipated consolidated future results of operations that the combined company will experience after the transaction. Three Months Ended Nine Months Ended (in millions of U.S. dollars, except per share data) September 30, 2016 September 30, 2016 Total revenues $ 8,521 $ 23,758 Net income $ 1,345 $ 2,591 Earnings per share Basic earnings per share $ 2.87 $ 5.54 Diluted earnings per share $ 2.85 $ 5.50

Investments

Investments	9 Months Ended
	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Investments	Investments a) Fixed maturities September 30, 2017 Amortized Cost Gross Unrealized Appreciation Gross Unrealized Depreciation Fair Value OTTI Recognized in AOCI (in millions of U.S. dollars) Available for sale U.S. Treasury and agency $ 3,571 $ 38 $ (27 ) $ 3,582 $ — Foreign 22,516 690 (107 ) 23,099 (2 ) Corporate securities 24,555 754 (83 ) 25,226 (4 ) Mortgage-backed securities 15,369 157 (115 ) 15,411 (1 ) States, municipalities, and political subdivisions 16,243 172 (47 ) 16,368 — $ 82,254 $ 1,811 $ (379 ) $ 83,686 $ (7 ) Held to maturity U.S. Treasury and agency $ 611 $ 13 $ (3 ) $ 621 $ — Foreign 616 28 — 644 — Corporate securities 2,531 63 (5 ) 2,589 — Mortgage-backed securities 1,223 35 — 1,258 — States, municipalities, and political subdivisions 5,179 77 (3 ) 5,253 — $ 10,160 $ 216 $ (11 ) $ 10,365 $ — December 31, 2016 Amortized Cost Gross Unrealized Appreciation Gross Unrealized Depreciation Fair Value OTTI Recognized in AOCI (in millions of U.S. dollars) Available for sale U.S. Treasury and agency $ 2,883 $ 32 $ (45 ) $ 2,870 $ — Foreign 20,929 636 (125 ) 21,440 (5 ) Corporate securities 23,736 580 (167 ) 24,149 (8 ) Mortgage-backed securities 14,066 135 (194 ) 14,007 (1 ) States, municipalities, and political subdivisions 17,922 72 (345 ) 17,649 — $ 79,536 $ 1,455 $ (876 ) $ 80,115 $ (14 ) Held to maturity U.S. Treasury and agency $ 655 $ 9 $ (3 ) $ 661 $ — Foreign 640 28 (1 ) 667 — Corporate securities 2,771 50 (26 ) 2,795 — Mortgage-backed securities 1,393 35 — 1,428 — States, municipalities, and political subdivisions 5,185 26 (92 ) 5,119 — $ 10,644 $ 148 $ (122 ) $ 10,670 $ — As discussed in Note 3 c ), if a credit loss is incurred on an impaired fixed maturity, an OTTI is considered to have occurred and the portion of the impairment not related to credit losses (non-credit OTTI) is recognized in OCI. Included in the “OTTI Recognized in AOCI” columns above are the cumulative amounts of non-credit OTTI recognized in OCI adjusted for subsequent sales, maturities, and redemptions. OTTI recognized in AOCI does not include the impact of subsequent changes in fair value of the related securities. In periods subsequent to a recognition of OTTI in OCI, changes in the fair value of the related fixed maturities are reflected in Net unrealized appreciation on investments in the Consolidated statements of shareholders’ equity. For the three and nine months ended September 30, 2017 , $1 million of net unrealized appreciation and $ 2 million of net unrealized depreciation, respectively, related to such securities is included in OCI. For the three and nine months ended September 30, 2016 , $13 million and $ 57 million , respectively, of net unrealized appreciation related to such securities is included in OCI. At September 30, 2017 and December 31, 2016 , AOCI included cumulative net unrealized appreciation of $7 million and $10 million , respectively, related to securities remaining in the investment portfolio for which a non-credit OTTI was recognized. Mortgage-backed securities (MBS) issued by U.S. government agencies are combined with all other to be announced mortgage-backed securities (TBAs) held (refer to Note 6 c) (iv)) and are included in the category, “Mortgage-backed securities”. Approximately 82 percent and 81 percent of the total mortgage-backed securities at September 30, 2017 and December 31, 2016 , respectively, are represented by investments in U.S. government agency bonds. The remainder of the mortgage exposure consists of collateralized mortgage obligations and non-government mortgage-backed securities, the majority of which provide a planned structure for principal and interest payments and carry a rating of AAA by the major credit rating agencies. The following table presents fixed maturities by contractual maturity: September 30 December 31 2017 2016 (in millions of U.S. dollars) Amortized Cost Fair Value Amortized Cost Fair Value Available for sale Due in 1 year or less $ 3,532 $ 3,556 $ 3,892 $ 3,913 Due after 1 year through 5 years 24,918 25,397 24,027 24,429 Due after 5 years through 10 years 28,009 28,488 27,262 27,379 Due after 10 years 10,426 10,834 10,289 10,387 66,885 68,275 65,470 66,108 Mortgage-backed securities 15,369 15,411 14,066 14,007 $ 82,254 $ 83,686 $ 79,536 $ 80,115 Held to maturity Due in 1 year or less $ 822 $ 828 $ 430 $ 435 Due after 1 year through 5 years 2,479 2,524 2,646 2,691 Due after 5 years through 10 years 2,821 2,866 2,969 2,944 Due after 10 years 2,815 2,889 3,206 3,172 8,937 9,107 9,251 9,242 Mortgage-backed securities 1,223 1,258 1,393 1,428 $ 10,160 $ 10,365 $ 10,644 $ 10,670 Expected maturities could differ from contractual maturities because borrowers may have the right to call or prepay obligations, with or without call or prepayment penalties. b) Equity securities September 30 December 31 (in millions of U.S. dollars) 2017 2016 Cost $ 723 $ 706 Gross unrealized appreciation 195 129 Gross unrealized depreciation (8 ) (21 ) Fair value $ 910 $ 814 c ) Net realized gains (losses) In accordance with guidance related to the recognition and presentation of OTTI, when an impairment related to a fixed maturity has occurred, OTTI is required to be recorded in Net income if management has the intent to sell the security or it is more likely than not that we will be required to sell the security before the recovery of its amortized cost. Further, in cases where we do not intend to sell the security and it is more likely than not that we will not be required to sell the security, we must evaluate the security to determine the portion of the impairment, if any, related to credit losses. If a credit loss is incurred, an OTTI is considered to have occurred and any portion of the OTTI related to credit losses must be reflected in Net income while the portion of OTTI related to all other factors is recognized in OCI. For fixed maturities held to maturity, OTTI recognized in OCI is accreted from AOCI to the amortized cost of the fixed maturity prospectively over the remaining term of the securities. Each quarter, securities in an unrealized loss position (impaired securities), including fixed maturities, securities lending collateral, equity securities, and other investments, are reviewed to identify impaired securities to be specifically evaluated for a potential OTTI. For all non-fixed maturities, OTTI is evaluated based on the following: • the amount of time a security has been in a loss position and the magnitude of the loss position; • the period in which cost is expected to be recovered, if at all, based on various criteria including economic conditions and other issuer-specific developments; and • our ability and intent to hold the security to the expected recovery period. As a general rule, we also consider that equity securities in an unrealized loss position for twelve consecutive months are other than temporarily impaired. For mutual funds included in equity securities in our Consolidated balance sheets, we employ analysis similar to fixed maturities, when applicable. Evaluation of potential credit losses related to fixed maturities We review each fixed maturity in an unrealized loss position to assess whether the security is a candidate for credit loss. Specifically, we consider credit rating, market price, and issuer-specific financial information, among other factors, to assess the likelihood of collection of all principal and interest as contractually due. Securities for which we determine that credit loss is likely are subjected to further analysis to estimate the credit loss recognized in Net income, if any. In general, credit loss recognized in Net income equals the difference between the security’s amortized cost and the net present value of its projected future cash flows discounted at the effective interest rate implicit in the debt security. All significant assumptions used in determining credit losses are subject to change as market conditions evolve. Corporate securities Projected cash flows for corporate securities (principally senior unsecured bonds) are driven primarily by assumptions regarding probability of default and also the timing and amount of recoveries associated with defaults. Chubb developed projected cash flows for corporate securities using market observable data, issuer-specific information, and credit ratings. We use historical default data by Moody’s Investors Service (Moody’s) rating category to calculate a 1-in-100 year probability of default, which results in a default assumption in excess of the historical mean default rate. Consistent with management's approach, Chubb assumed a 32 percent recovery rate (the par value of a defaulted security that will be recovered) across all rating categories rather than using Moody's historical mean recovery rate of 42 percent. We believe that use of a default assumption in excess of the historical mean is conservative in light of current market conditions. For the three and nine months ended September 30, 2017 , credit losses recognized in Net income for corporate securities were $3 million and $ 5 million , respectively. For the three and nine months ended September 30, 2016 , credit losses recognized in Net income for corporate securities were $4 million and $ 28 million , respectively. Mortgage-backed securities For mortgage-backed securities, credit impairment is assessed using a cash flow model that estimates the cash flows on the underlying mortgages, using the security-specific collateral and transaction structure. The model estimates cash flows from the underlying mortgage loans and distributes those cash flows to various tranches of securities, considering the transaction structure and any subordination and credit enhancements that exist in that structure. The cash flow model incorporates actual cash flows on the mortgage-backed securities through the current period and then projects the remaining cash flows using a number of assumptions, including default rates, prepayment rates, and loss severity rates (the par value of a defaulted security that will not be recovered) on foreclosed properties. For the three and nine months ended September 30, 2017 , there were no credit losses recognized in Net income for mortgage-backed securities. For the three and nine months ended September 30, 2016 , there were $1 million in credit losses recognized in Net income for mortgage-backed securities. The following table presents the Net realized gains (losses) and the losses included in Net realized gains (losses) and OCI as a result of conditions which caused us to conclude the decline in fair value of certain investments was “other-than-temporary”: Three Months Ended Nine Months Ended September 30 September 30 (in millions of U.S. dollars) 2017 2016 2017 2016 Fixed maturities: OTTI on fixed maturities, gross $ (5 ) $ (7 ) $ (16 ) $ (85 ) OTTI on fixed maturities recognized in OCI (pre-tax) — — 1 8 OTTI on fixed maturities, net (5 ) (7 ) (15 ) (77 ) Gross realized gains excluding OTTI 30 47 109 149 Gross realized losses excluding OTTI (19 ) (13 ) (77 ) (228 ) Total fixed maturities 6 27 17 (156 ) Equity securities: OTTI on equity securities (1 ) (1 ) (9 ) (7 ) Gross realized gains excluding OTTI 6 19 21 63 Gross realized losses excluding OTTI (1 ) (12 ) (2 ) (17 ) Total equity securities 4 6 10 39 OTTI on other investments (2 ) (4 ) (11 ) (7 ) Foreign exchange gains 15 29 10 46 Investment and embedded derivative instruments (14 ) 1 (24 ) (85 ) Fair value adjustments on insurance derivative 54 89 265 (270 ) S&P put options and futures (57 ) (45 ) (169 ) (88 ) Other derivative instruments (5 ) 3 (4 ) 1 Other (11 ) (6 ) (10 ) 10 Net realized gains (losses) $ (10 ) $ 100 $ 84 $ (510 ) The following table presents a roll-forward of pre-tax credit losses related to fixed maturities for which a portion of OTTI was recognized in OCI: Three Months Ended Nine Months Ended September 30 September 30 (in millions of U.S. dollars) 2017 2016 2017 2016 Balance of credit losses related to securities still held – beginning of period $ 29 $ 51 $ 35 $ 53 Additions where no OTTI was previously recorded 2 4 3 16 Additions where an OTTI was previously recorded 1 1 2 13 Reductions for securities sold during the period (7 ) (11 ) (15 ) (37 ) Balance of credit losses related to securities still held – end of period $ 25 $ 45 $ 25 $ 45 d) Gross unrealized loss At September 30, 2017 , there were 7,455 fixed maturities out of a total of 30,933 fixed maturities in an unrealized loss position. The largest single unrealized loss in the fixed maturities was $7 million . There were 59 equity securities out of a total of 317 equity securities in an unrealized loss position. The largest single unrealized loss in the equity securities was $1 million . Fixed maturities in an unrealized loss position at September 30, 2017 , comprised both investment grade and below investment grade securities for which fair value declined primarily due to widening credit spreads since the date of purchase. The following tables present, for all securities in an unrealized loss position (including securities on loan), the aggregate fair value and gross unrealized loss by length of time the security has continuously been in an unrealized loss position: 0 – 12 Months Over 12 Months Total September 30, 2017 Fair Value Gross Unrealized Loss Fair Value Gross Unrealized Loss Fair Value Gross Unrealized Loss (in millions of U.S. dollars) U.S. Treasury and agency $ 1,763 $ (13 ) $ 656 $ (17 ) $ 2,419 $ (30 ) Foreign 5,353 (85 ) 894 (22 ) 6,247 (107 ) Corporate securities 3,373 (48 ) 788 (40 ) 4,161 (88 ) Mortgage-backed securities 6,946 (96 ) 749 (19 ) 7,695 (115 ) States, municipalities, and political subdivisions 4,548 (28 ) 839 (22 ) 5,387 (50 ) Total fixed maturities 21,983 (270 ) 3,926 (120 ) 25,909 (390 ) Equity securities 103 (8 ) — — 103 (8 ) Other investments 157 (9 ) — — 157 (9 ) Total $ 22,243 $ (287 ) $ 3,926 $ (120 ) $ 26,169 $ (407 ) 0 – 12 Months Over 12 Months Total December 31, 2016 Fair Value Gross Unrealized Loss Fair Value Gross Unrealized Loss Fair Value Gross Unrealized Loss (in millions of U.S. dollars) U.S. Treasury and agency $ 2,216 $ (48 ) $ — $ — $ 2,216 $ (48 ) Foreign 5,918 (99 ) 386 (27 ) 6,304 (126 ) Corporate securities 7,021 (149 ) 641 (44 ) 7,662 (193 ) Mortgage-backed securities 8,638 (189 ) 234 (5 ) 8,872 (194 ) States, municipalities, and political subdivisions 19,448 (435 ) 49 (2 ) 19,497 (437 ) Total fixed maturities 43,241 (920 ) 1,310 (78 ) 44,551 (998 ) Equity securities 199 (21 ) — — 199 (21 ) Other investments 201 (18 ) — — 201 (18 ) Total $ 43,641 $ (959 ) $ 1,310 $ (78 ) $ 44,951 $ (1,037 ) e) Restricted assets Chubb is required to maintain assets on deposit with various regulatory authorities to support its insurance and reinsurance operations. These requirements are generally promulgated in the statutory regulations of the individual jurisdictions. The assets on deposit are available to settle insurance and reinsurance liabilities. Chubb is also required to restrict assets pledged under repurchase agreements, which represent Chubb's agreement to sell securities and repurchase them at a future date for a predetermined price. We also use trust funds in certain large reinsurance transactions where the trust funds are set up for the benefit of the ceding companies and generally take the place of letter of credit (LOC) requirements. We also have investments in segregated portfolios primarily to provide collateral or guarantees for LOC and derivative transactions. Included in restricted assets at September 30, 2017 and December 31, 2016 are investments, primarily fixed maturities, totaling $22.8 billion and $20.1 billion, respectively, and cash of $105 million and $103 million, respectively. The following table presents the components of restricted assets: September 30 December 31 (in millions of U.S. dollars) 2017 2016 Trust funds $ 16,391 $ 13,880 Deposits with U.S. regulatory authorities 2,361 2,203 Deposits with non-U.S. regulatory authorities 2,294 2,191 Assets pledged under repurchase agreements 1,441 1,461 Other pledged assets 377 435 $ 22,864 $ 20,170

Fair value measurements

Fair value measurements	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Fair value measurements	Fair value measurements a ) Fair value hierarchy Fair value of financial assets and financial liabilities is estimated based on the framework established in the fair value accounting guidance. The guidance defines fair value as the price to sell an asset or transfer a liability (an exit price) in an orderly transaction between market participants and establishes a three-level valuation hierarchy based on the reliability of the inputs. The fair value hierarchy gives the highest priority to quoted prices in active markets and the lowest priority to unobservable data. The three levels of the hierarchy are as follows: • Level 1 – Unadjusted quoted prices for identical assets or liabilities in active markets; • Level 2 – Includes, among other items, inputs other than quoted prices that are observable for the asset or liability such as interest rates and yield curves, quoted prices for similar assets and liabilities in active markets, and quoted prices for identical or similar assets and liabilities in markets that are not active; and • Level 3 – Inputs that are unobservable and reflect management’s judgments about assumptions that market participants would use in pricing an asset or liability. We categorize financial instruments within the valuation hierarchy at the balance sheet date based upon the lowest level of inputs that are significant to the fair value measurement. Accordingly, transfers between levels within the valuation hierarchy occur when there are significant changes to the inputs, such as increases or decreases in market activity, changes to the availability of current prices, changes to the transparency to underlying inputs, and whether there are significant variances in quoted prices. Transfers in and/or out of any level are assumed to occur at the end of the period. We use pricing services to obtain fair value measurements for the majority of our investment securities. Based on management’s understanding of the methodologies used, these pricing services only produce an estimate of fair value if there is observable market information that would allow them to make a fair value estimate. Based on our understanding of the market inputs used by the pricing services, all applicable investments have been valued in accordance with GAAP. We do not adjust prices obtained from pricing services. The following is a description of the valuation techniques and inputs used to determine fair values for financial instruments carried at fair value, as well as the general classification of such financial instruments pursuant to the valuation hierarchy. Fixed maturities We use pricing services to estimate fair value measurements for the majority of our fixed maturities. The pricing services use market quotations for fixed maturities that have quoted prices in active markets; such securities are classified within Level 1. For fixed maturities other than U.S. Treasury securities that generally do not trade on a daily basis, the pricing services prepare estimates of fair value measurements using their pricing applications, which include available relevant market information, benchmark curves, benchmarking of like securities, sector groupings, and matrix pricing. Additional valuation factors that can be taken into account are nominal spreads, dollar basis, and liquidity adjustments. The pricing services evaluate each asset class based on relevant market and credit information, perceived market movements, and sector news. The market inputs used in the pricing evaluation, listed in the approximate order of priority include: benchmark yields, reported trades, broker/dealer quotes, issuer spreads, two-sided markets, benchmark securities, bids, offers, reference data, and industry and economic events. The extent of the use of each input is dependent on the asset class and the market conditions. Given the asset class, the priority of the use of inputs may change, or some market inputs may not be relevant. Additionally, fixed maturities valuation is more subjective when markets are less liquid due to the lack of market based inputs (i.e., stale pricing), which may increase the potential that an investment's estimated fair value is not reflective of the price at which an actual transaction would occur. The overwhelming majority of fixed maturities are classified within Level 2 because the most significant inputs used in the pricing techniques are observable. For a small number of fixed maturities, we obtain a single broker quote (typically from a market maker). Due to the disclaimers on the quotes that indicate that the price is indicative only, we include these fair value estimates in Level 3. Equity securities Equity securities with active markets are classified within Level 1 as fair values are based on quoted market prices. For equity securities in markets which are less active, fair values are based on market valuations and are classified within Level 2. Equity securities for which pricing is unobservable are classified within Level 3. Short-term investments Short-term investments, which comprise securities due to mature within one year of the date of purchase that are traded in active markets, are classified within Level 1 as fair values are based on quoted market prices. Securities such as commercial paper and discount notes are classified within Level 2 because these securities are typically not actively traded due to their approaching maturity and, as such, their cost approximates fair value. Short-term investments for which pricing is unobservable are classified within Level 3. Other investments Fair values for the majority of Other investments including investments in partially-owned investment companies, investment funds, and limited partnerships are based on their respective net asset values or equivalent (NAV) and are excluded from the fair value hierarchy table below. Certain of our long-duration contracts are supported by assets that do not qualify for separate account reporting under GAAP. These assets comprise mutual funds classified within Level 1 in the valuation hierarchy on the same basis as other equity securities traded in active markets. Other investments also include equity securities classified within Level 1, and fixed maturities, classified within Level 2, held in rabbi trusts maintained by Chubb for deferred compensation plans and are classified within the valuation hierarchy on the same basis as other equity securities and fixed maturities. Other investments for which pricing is unobservable are classified within Level 3. Securities lending collateral The underlying assets included in Securities lending collateral in the Consolidated balance sheets are fixed maturities which are classified in the valuation hierarchy on the same basis as other fixed maturities. Excluded from the valuation hierarchy is the corresponding liability related to Chubb’s obligation to return the collateral plus interest as it is reported at contract value and not fair value in the Consolidated balance sheets. Investment derivative instruments Actively traded investment derivative instruments, including futures, options, and forward contracts are classified within Level 1 as fair values are based on quoted market prices. The fair value of cross-currency swaps is based on market valuations and is classified within Level 2. Investment derivative instruments are recorded in either Other assets or Accounts payable, accrued expenses, and other liabilities in the Consolidated balance sheets. Other derivative instruments We generally maintain positions in other derivative instruments including exchange-traded equity futures contracts designed to limit exposure to a severe equity market decline, which would cause an increase in expected claims and, therefore, an increase in reserves for our guaranteed minimum death benefits (GMDB) and guaranteed living benefits (GLB) reinsurance business. Our position in exchange-traded equity futures contracts is classified within Level 1. The fair value of the majority of the remaining positions in other derivative instruments is based on significant observable inputs including equity security and interest rate indices. Accordingly, these are classified within Level 2. Other derivative instruments based on unobservable inputs are classified within Level 3. Other derivative instruments are recorded in either Other assets or Accounts payable, accrued expenses, and other liabilities in the Consolidated balance sheets. Separate account assets Separate account assets represent segregated funds where investment risks are borne by the customers, except to the extent of certain guarantees made by Chubb. Separate account assets comprise mutual funds classified within Level 1 in the valuation hierarchy on the same basis as other equity securities traded in active markets. Separate account assets also include fixed maturities classified within Level 2 because the most significant inputs used in the pricing techniques are observable. Excluded from the valuation hierarchy are the corresponding liabilities as they are reported at contract value and not fair value in the Consolidated balance sheets. Separate account assets are recorded in Other assets in the Consolidated balance sheets. Guaranteed living benefits The GLB arises from life reinsurance programs covering living benefit guarantees whereby we assume the risk of guaranteed minimum income benefits (GMIB) and guaranteed minimum accumulation benefits (GMAB) associated with variable annuity contracts. GLB’s are recorded in Accounts payable, accrued expenses, and other liabilities and Future policy benefits in the Consolidated balance sheets. For GLB reinsurance, Chubb estimates fair value using an internal valuation model which includes current market information and estimates of policyholder behavior. All of the treaties contain claim limits, which are factored into the valuation model. The fair value depends on a number of factors, including interest rates, equity markets, credit risk, current account value, market volatility, expected annuitization rates and other policyholder behavior, and changes in policyholder mortality. The most significant policyholder behavior assumptions include lapse rates and the GMIB annuitization rates. Assumptions regarding lapse rates and GMIB annuitization rates differ by treaty, but the underlying methodologies to determine rates applied to each treaty are comparable. A lapse rate is the percentage of in-force policies surrendered in a given calendar year. All else equal, as lapse rates increase, ultimate claim payments will decrease. The GMIB annuitization rate is the percentage of policies for which the policyholder will elect to annuitize using the guaranteed benefit provided under the GMIB. All else equal, as GMIB annuitization rates increase, ultimate claim payments will increase, subject to treaty claim limits. The effect of changes in key market factors on assumed lapse and annuitization rates reflect emerging trends using data available from cedants. For treaties with limited experience, rates are established in line with data received from other ceding companies adjusted, as appropriate, with industry estimates. The model and related assumptions are regularly re-evaluated by management and enhanced, as appropriate, based upon additional experience obtained related to policyholder behavior and availability of updated information such as market conditions, market participant assumptions, and demographics of in-force annuities. Because of the significant use of unobservable inputs including policyholder behavior, GLB reinsurance is classified within Level 3. During the nine months ended September 30, 2017, we updated aspects of our valuation model relating to interest rates. This resulted in a decrease to the fair value of GLB liabilities generating a realized gain of approximately $ 94 million . During the nine months ended September 30, 2017, there were no other material changes to actuarial or behavioral assumptions. For detailed information on our lapse and annuitization rate assumptions, refer to Note 4 to the Consolidated Financial Statements of our 2016 Form 10-K. Financial instruments measured at fair value on a recurring basis, by valuation hierarchy September 30, 2017 Level 1 Level 2 Level 3 Total (in millions of U.S. dollars) Assets: Fixed maturities available for sale U.S. Treasury and agency $ 2,941 $ 641 $ — $ 3,582 Foreign — 23,009 90 23,099 Corporate securities — 24,307 919 25,226 Mortgage-backed securities — 15,367 44 15,411 States, municipalities, and political subdivisions — 16,368 — 16,368 2,941 79,692 1,053 83,686 Equity securities 858 — 52 910 Short-term investments 1,804 1,187 — 2,991 Other investments (1) 446 292 252 990 Securities lending collateral — 1,757 — 1,757 Investment derivative instruments 15 — — 15 Separate account assets 2,414 100 — 2,514 Total assets measured at fair value (1) $ 8,478 $ 83,028 $ 1,357 $ 92,863 Liabilities: Investment derivative instruments $ 37 $ — $ — $ 37 Other derivative instruments 25 — 2 27 GLB (2) — — 303 303 Total liabilities measured at fair value $ 62 $ — $ 305 $ 367 (1) Excluded from the table above are partially-owned investments, investment funds, and limited partnerships of $ 3,669 million and other investments of $ 18 million at September 30, 2017 measured using NAV as a practical expedient. (2) Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. December 31, 2016 Level 1 Level 2 Level 3 Total (in millions of U.S. dollars) Assets: Fixed maturities available for sale U.S. Treasury and agency $ 2,175 $ 695 $ — $ 2,870 Foreign — 21,366 74 21,440 Corporate securities — 23,468 681 24,149 Mortgage-backed securities — 13,962 45 14,007 States, municipalities, and political subdivisions — 17,649 — 17,649 2,175 77,140 800 80,115 Equity securities 773 — 41 814 Short-term investments 1,757 1,220 25 3,002 Other investments (1) 384 259 225 868 Securities lending collateral — 1,092 — 1,092 Investment derivative instruments 31 — — 31 Other derivative instruments 3 — — 3 Separate account assets 1,784 95 — 1,879 Total assets measured at fair value (1) $ 6,907 $ 79,806 $ 1,091 $ 87,804 Liabilities: Investment derivative instruments $ 54 $ — $ — $ 54 Other derivative instruments — — 13 13 GLB (2) — — 559 559 Total liabilities measured at fair value $ 54 $ — $ 572 $ 626 (1) Excluded from the table above are partially-owned investments, investment funds, and limited partnerships of $3,626 million and other investments of $25 million at December 31, 2016 measured using NAV as a practical expedient. (2) Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. There were no transfers of financial instruments between Level 1 and Level 2 for the three and nine months ended September 30, 2017 and 2016. Fair value of alternative investments Alternative investments include investment funds, limited partnerships, and partially-owned investment companies measured at fair value using NAV as a practical expedient. The following table presents, by investment category, the expected liquidation period, fair value, and maximum future funding commitments of alternative investments: September 30 December 31 Expected Liquidation Period of Underlying Assets 2017 2016 (in millions of U.S. dollars) Fair Value Maximum Future Funding Commitments Fair Value Maximum Future Funding Commitments Financial 5 to 9 Years $ 566 $ 367 $ 548 $ 428 Real Assets 3 to 7 Years 635 148 536 230 Distressed 5 to 9 Years 327 157 485 179 Private Credit 3 to 7 Years 216 329 236 259 Traditional 3 to 9 Years 1,643 729 1,550 930 Vintage 1 to 2 Years 18 — 21 14 Investment funds Not Applicable 264 — 251 — $ 3,669 $ 1,730 $ 3,627 $ 2,040 Included in all categories in the above table, except for Investment funds, are investments for which Chubb will never have the contractual option to redeem but receives distributions based on the liquidation of the underlying assets. Further, for all categories except for Investment funds, Chubb does not have the ability to sell or transfer the investments without the consent from the general partner of individual funds. Investment Category: Consists of investments in private equity funds: Financial targeting financial services companies such as financial institutions and insurance services worldwide Real Assets targeting investments related to hard physical assets such as real estate, infrastructure and natural resources Distressed targeting distressed corporate debt/credit and equity opportunities in the U.S. Private Credit targeting privately originated corporate debt investments including senior secured loans and subordinated bonds Traditional employing traditional private equity investment strategies such as buyout and growth equity globally Vintage made before 2002 and where the funds’ commitment periods had already expired Investment funds Chubb’s investment funds employ various investment strategies such as long/short equity and arbitrage/distressed. Included in this category are investments for which Chubb has the option to redeem at agreed upon value as described in each investment fund’s subscription agreement. Depending on the terms of the various subscription agreements, investment fund investments may be redeemed monthly, quarterly, semi-annually, or annually. If Chubb wishes to redeem an investment fund investment, it must first determine if the investment fund is still in a lock-up period (a time when Chubb cannot redeem its investment so that the investment fund manager has time to build the portfolio). If the investment fund is no longer in its lock-up period, Chubb must then notify the investment fund manager of its intention to redeem by the notification date prescribed by the subscription agreement. Subsequent to notification, the investment fund can redeem Chubb’s investment within several months of the notification. Notice periods for redemption of the investment funds range between 5 and 120 days. Chubb can redeem its investment funds without consent from the investment fund managers. Level 3 financial instruments The fair values of assets and liabilities measured at fair value using significant unobservable inputs (Level 3) consist of various inputs and assumptions that management makes when determining fair value. Management analyzes changes in fair value measurements classified within Level 3 by comparing pricing and returns of our investments to benchmarks, including month-over-month movements, investment credit spreads, interest rate movements, and credit quality of securities. The following table presents the significant unobservable inputs used in the Level 3 liability valuations. Excluded from the table below are inputs used to determine the fair value of Level 3 assets which are based on single broker quotes and contain no quantitative unobservable inputs developed by management. (in millions of U.S. dollars, except for percentages) Fair Value Valuation Technique Significant Unobservable Inputs Ranges September 30, 2017 December 31, 2016 GLB (1) $ 303 $ 559 Actuarial model Lapse rate 3% – 34% Annuitization rate 0% – 78% (1) Discussion of the most significant inputs used in the fair value measurement of GLB and the sensitivity of those assumptions is included within Note 4 a) Guaranteed living benefits. The following tables present a reconciliation of the beginning and ending balances of financial instruments measured at fair value using significant unobservable inputs (Level 3): Assets Liabilities Three Months Ended Available-for-Sale Debt Securities Equity securities Short-term investments Other investments Other derivative instruments GLB (1) September 30, 2017 Foreign Corporate securities MBS (in millions of U.S. dollars) Balance – beginning of period $ 85 $ 747 $ 45 $ 39 $ 7 $ 243 $ 2 $ 357 Transfers into Level 3 — 111 — — — — — — Transfers out of Level 3 (3 ) (26 ) — — — — — — Change in Net Unrealized Gains (Losses) included in OCI 1 (1 ) — — — — — — Net Realized Gains/Losses — — — 1 — — — (54 ) Purchases 24 169 7 17 1 15 — — Sales (14 ) (24 ) — (5 ) — — — — Settlements (3 ) (57 ) (8 ) — (8 ) (6 ) — — Balance – end of period $ 90 $ 919 $ 44 $ 52 $ — $ 252 $ 2 $ 303 Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date $ — $ — $ — $ — $ — $ — $ — $ (54 ) (1) Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $635 million at September 30, 2017, and $684 million at June 30, 2017, which includes a fair value derivative adjustment of $303 million and $357 million , respectively. Assets Liabilities Three Months Ended Available-for-Sale Debt Securities Equity Short-term investments Other Other derivative instruments GLB (1) September 30, 2016 Foreign Corporate MBS (in millions of U.S. dollars) Balance – beginning of period $ 87 $ 281 $ 49 $ 37 $ 50 $ 216 $ 10 $ 971 Transfers into Level 3 — — — — — — — — Transfers out of Level 3 — — — — — — — — Change in Net Unrealized Gains (Losses) included in OCI (1 ) 6 — 3 — 4 — — Net Realized Gains/Losses — (4 ) — — — — — (88 ) Purchases 20 348 — — 12 8 — — Sales (2 ) (18 ) (3 ) (3 ) — — — — Settlements (1 ) (7 ) — — — (5 ) (2 ) — Balance – end of period $ 103 $ 606 $ 46 $ 37 $ 62 $ 223 $ 8 $ 883 Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date $ — $ (4 ) $ — $ — $ — $ — $ — $ (88 ) (1) Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $1.2 billion at September 30, 2016 , and $1.3 billion at June 30, 2016, which includes a fair value derivative adjustment of $883 million and $971 million, respectively. Assets Liabilities Nine Months Ended Available-for-Sale Debt Securities Equity securities Short-term investments Other investments Other derivative instruments GLB (1) September 30, 2017 Foreign Corporate securities MBS (in millions of U.S. dollars) Balance – beginning of period $ 74 $ 681 $ 45 $ 41 $ 25 $ 225 $ 13 $ 559 Transfers into Level 3 — 168 — — — — — 9 Transfers out of Level 3 (3 ) (93 ) — — — — (9 ) — Change in Net Unrealized Gains (Losses) included in OCI 3 (9 ) — 1 — 3 — — Net Realized Gains/Losses 1 (1 ) — 1 — — (2 ) (265 ) Purchases 57 390 8 23 15 39 — — Sales (36 ) (79 ) (1 ) (14 ) — — — — Settlements (6 ) (138 ) (8 ) — (40 ) (15 ) — — Balance – end of period $ 90 $ 919 $ 44 $ 52 $ — $ 252 $ 2 $ 303 Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date $ — $ — $ — $ — $ — $ — $ (2 ) $ (265 ) (1) Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $635 million at September 30, 2017, and $853 million at December 31, 2016, which includes a fair value derivative adjustment of $303 million and $559 million , respectively. Assets Liabilities Nine Months Ended Available-for-Sale Debt Securities Equity Short-term investments Other Other derivative instruments GLB (1) September 30, 2016 Foreign Corporate MBS (in millions of U.S. dollars) Balance – beginning of period $ 57 $ 174 $ 53 $ 16 $ — $ 212 $ 6 $ 609 Transfers into Level 3 9 18 — — — — — — Transfers out of Level 3 (2 ) — — — — — — — Change in Net Unrealized Gains (Losses) included in OCI 8 17 — 2 — 4 — — Net Realized Gains/Losses (6 ) (12 ) — 1 — — 2 274 Purchases (2) 52 472 1 23 62 22 2 — Sales (10 ) (48 ) (8 ) (5 ) — — — — Settlements (5 ) (15 ) — — — (15 ) (2 ) — Balance – end of period $ 103 $ 606 $ 46 $ 37 $ 62 $ 223 $ 8 $ 883 Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date $ (5 ) $ (11 ) $ — $ — $ — $ — $ 2 $ 274 (1) Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $1.2 billion at September 30, 2016 , and $888 million at December 31, 2015, which includes a fair value derivative adjustment of $883 million and $609 million , respectively. (2) Includes acquired invested assets as a result of the Chubb Corp acquisition. b) Financial instruments disclosed, but not measured, at fair value Chubb uses various financial instruments in the normal course of its business. Our insurance contracts are excluded from fair value of financial instruments accounting guidance, and therefore, are not included in the amounts discussed below. The carrying values of cash, other assets, other liabilities, and other financial instruments not included below approximated their fair values. Investments in partially-owned insurance companies Fair values for investments in partially-owned insurance companies are based on Chubb’s share of the net assets based on the financial statements provided by those companies and are excluded from the valuation hierarchy tables below. Short- and long-term debt, repurchase agreements, and trust preferred securities Where practical, fair values for short-term debt, long-term debt, repurchase agreements, and trust preferred securities are estimated using discounted cash flow calculations based principally on observable inputs including incremental borrowing rates, which reflect Chubb’s credit rating, for similar types of borrowings with maturities consistent with those remaining for the debt being valued. The following tables present fair value, by valuation hierarchy, and carrying value of the financial instruments not measured at fair value: September 30, 2017 Fair Value Carrying Value (in millions of U.S. dollars) Level 1 Level 2 Level 3 Total Assets: Fixed maturities held to maturity U.S. Treasury and agency $ 563 $ 58 $ — $ 621 $ 611 Foreign — 644 — 644 616 Corporate securities — 2,578 11 2,589 2,531 Mortgage-backed securities — 1,258 — 1,258 1,223 States, municipalities, and political subdivisions — 5,253 — 5,253 5,179 Total assets $ 563 $ 9,791 $ 11 $ 10,365 $ 10,160 Liabilities: Repurchase agreements $ — $ 1,408 $ — $ 1,408 $ 1,408 Short-term debt — 1,025 — 1,025 1,020 Long-term debt — 12,273 — 12,273 11,559 Trust preferred securities — 467 — 467 308 Total liabilities $ — $ 15,173 $ — $ 15,173 $ 14,295 December 31, 2016 Fair Value Carrying Value (in millions of U.S. dollars) Level 1 Level 2 Level 3 Total Assets: Fixed maturities held to maturity U.S. Treasury and agency $ 555 $ 106 $ — $ 661 $ 655 Foreign — 667 — 667 640 Corporate securities — 2,782 13 2,795 2,771 Mortgage-backed securities — 1,428 — 1,428 1,393 States, municipalities, and political subdivisions — 5,119 — 5,119 5,185 Total assets $ 555 $ 10,102 $ 13 $ 10,670 $ 10,644 Liabilities: Repurchase agreements $ — $ 1,403 $ — $ 1,403 $ 1,403 Short-term debt — 503 — 503 500 Long-term debt — 12,998 — 12,998 12,610 Trust preferred securities — 456 — 456 308 Total liabilities $ — $ 15,360 $ — $ 15,360 $ 14,821

Unpaid losses and loss expenses

Unpaid losses and loss expenses Unpaid losses and loss expenses	9 Months Ended
	Sep. 30, 2017
Liability for Claims and Claims Adjustment Expense [Abstract]
Liability for Future Policy Benefits and Unpaid Claims Disclosure [Text Block]	5. Unpaid losses and loss expenses The following table presents a reconciliation of beginning and ending Unpaid losses and loss expenses: Nine Months Ended September 30 (in millions of U.S. dollars) 2017 2016 Gross unpaid losses and loss expenses – beginning of period $ 60,540 $ 37,303 Reinsurance recoverable on unpaid losses (1) (12,708 ) (10,741 ) Net unpaid losses and loss expenses – beginning of period 47,832 26,562 Acquisition of subsidiaries — 21,402 Total 47,832 47,964 Net losses and loss expenses incurred in respect of losses occurring in: Current year 14,963 13,169 Prior years (2) (781 ) (972 ) Total 14,182 12,197 Net losses and loss expenses paid in respect of losses occurring in: Current year 3,937 3,865 Prior years 8,389 7,470 Total 12,326 11,335 Foreign currency revaluation and other 596 (155 ) Net unpaid losses and loss expenses – end of period 50,283 48,671 Reinsurance recoverable on unpaid losses (1) 13,870 12,676 Gross unpaid losses and loss expenses – end of period $ 64,153 $ 61,347 (1) Net of provision for uncollectible reinsurance. (2) Relates to prior period loss reserve development only and excludes prior period development related to reinstatement premiums, expense adjustments, and earned premiums totaling $110 million and $75 million for the nine months ended September 30, 2017 and 2016, respectively. The increase in gross and net unpaid losses and loss expenses in 2017 primarily reflects the significant catastrophe events during the third quarter of 2017, principally from hurricanes Harvey, Irma and Maria and the earthquakes in Mexico. Prior Period Development Prior period development arises from changes to loss estimates recognized in the current year that relate to loss events that occurred in previous calendar years and excludes the effect of losses from the development of earned premium from previous accident years. Significant prior period movements by segment, principally driven by reserve reviews completed during each respective period, are discussed in more detail below. The remaining net development for long-tail lines and short-tail business for each segment and Corporate comprises numerous favorable and adverse movements across a number of lines and accident years, none of which is significant individually or in the aggregate. Long-tail lines include lines such as workers' compensation, general liability, and professional liability; while short-tail lines include lines such as most property lines, energy, personal accident, and agriculture. During the third quarter of 2017, we determined that the classification of loss development for certain businesses, previously grouped within the short-tail discussion below, would be more appropriately classified as long-tail to better align with the classification of these businesses within our loss development tables in the 2016 Form 10-K. We also determined that the loss development for certain other businesses should be reclassified from long-tail to short-tail. We updated our 2016 and year-to-date 2017 discussions below to conform to the current period presentation. These changes to the previously disclosed amount have no impact to our financial condition and results of operations. North America Commercial P&C Insurance 2017 For the three months ended September 30, 2017 , net favorable PPD was $236 million , which was the net result of several underlying favorable and adverse movements, and was driven by the following principal changes: • Net favorable development of $242 million in long-tail business, primarily from: • Favorable development of $140 million in commercial excess and umbrella portfolios primarily in accident years 2011 and prior driven by lower paid and reported loss activity relative to prior expectations as well as an increase in weighting towards experience-based methods; • Favorable development of $44 million in workers' compensation business mainly impacting accident years 2013 and prior, driven by lower than expected paid and reported loss activity, and revisions to development patterns used in our loss projection methods for select portfolios; and • Net favorable development of $28 million on several large multi-line prospective deals primarily impacting the 2012 and 2013 accident years, due to lower than expected reported loss activity. These structured deals typically cover large clients for multiple product lines and with varying loss limitations; this development is net of premium adjustments of $26 million tied to the loss performance of the particular deals. • Net adverse development of $6 million in short-tail business across a number of accident years, none of which were significant individually or in the aggregate. For the nine months ended September 30, 2017 , net favorable PPD was $546 million , which was the net result of several underlying favorable and adverse movements, and was driven by the following principal changes: • Net favorable development of $431 million in long-tail business, primarily from: • Net favorable development of $99 million in our workers’ compensation businesses (excluding excess compensation) with favorable development of $37 million in the 2016 accident year related to our annual assessment of multi-claimant events including industrial accidents. Consistent with prior years, we reviewed these potential exposures after the close of the accident year to allow for late reporting or identification of significant losses. Net favorable development of $62 million was principally due to lower than expected loss experience and revision to development patterns used in our loss projection methods, mainly impacting accident years 2013 and prior, and partly offset by smaller adverse development in the more recent prior accident years; • Net favorable development of $213 million in our commercial excess and umbrella portfolios, primarily in accident years 2011 and prior, driven by lower than expected reported loss activity, and an increase in weighting towards experience-based methods; • Favorable development of $27 million in our commercial-multi peril (CMP) and monoline general liability lines, driven by favorable paid and reported loss activity relative to prior expectations, principally in accident years 2008 through 2013; • Net favorable development of $30 million in our professional Errors and Omissions (E&O) portfolios, primarily in the 2012 and 2013 accident years, arising from lower than expected reported loss activity, partially offset by claim-specific adverse development; and • Favorable development of $28 million in large multi-line accounts due primarily to the same factors experienced for the three months ended September 30, 2017. • Net favorable development of $115 million in short-tail business, primarily from: • Net favorable development of $45 million in our credit-related business, primarily due to lower than expected claims severity in the 2015 accident year; • Favorable development of $43 million in property lines, primarily in our commercial property portfolios, driven by lower than expected loss emergence in the 2014 and 2016 accident years; and • Net favorable development of $19 million in our accident & health (A&H) business, primarily due to lower than expected loss emergence in the 2015 and 2016 accident years. 2016 For the three months ended September 30, 2016 , net favorable PPD was $187 million , which was the net result of several underlying favorable and adverse movements, and was driven by the following principal changes: • Net favorable development of $167 million in long-tail business, primarily from favorable development of $127 million in our commercial excess and umbrella portfolios, impacting the 2010 and prior accident years, driven by continued lower than expected reported loss activity and an increase in weighting towards experience-based methods; and • Net favorable development of $20 million in short-tail business, principally from our property portfolios, primarily impacting the 2014 and 2015 accident years, resulting from lower than expected loss emergence. For the nine months ended September 30, 2016 , net favorable PPD was $533 million , which was the net result of several underlying favorable and adverse movements, and was driven by the following principal changes: • Net favorable development of $473 million in long-tail business, primarily from: • Favorable development of $272 million in our commercial excess and umbrella portfolios, primarily in accident years 2010 and prior, driven by lower than expected reported loss activity and an increase in weighting towards experience-based methods; in general, the severity of claims has been less than expected; • Net favorable development of $134 million in our workers’ compensation lines, including excess lines, with favorable development of $40 million in the 2015 accident year related to our annual assessment of multi-claimant events including industrial accidents. Favorable development of $91 million in accident years 2012 and prior was principally due to lower than expected loss experience and revision to the basis for selecting development patterns used in our loss projection methods; • Favorable development of $69 million in our professional E&O portfolios, primarily impacting the 2012 and prior accident years and arising from both lower than expected reported loss activity and re-assessments of remaining claim-specific liabilities for the older accident years; • Net favorable development of $20 million in our primary general and package liability lines from favorable development due to lower than expected reported and paid activity, principally in accident years 2007 through 2014; and • Net favorable development of $60 million in short-tail business, primarily from net favorable development of $46 million in our property portfolios, primarily impacting the 2014 and 2015 accident years, resulting from lower than expected loss emergence. North America Personal P&C Insurance 2017 For the three months ended September 30, 2017 , net adverse PPD was $32 million , which was the net result of several underlying favorable and adverse movements, and was driven by the following principal changes: • Net adverse development of $98 million in our homeowners lines, primarily impacting the 2016 accident year, due to higher than expected loss severity; and • Net favorable development of $58 million in our personal excess lines primarily impacting the 2014 accident year, due to lower than expected loss experience and an increase weighting towards experience-based methods. For the nine months ended September 30, 2017 , net adverse PPD was $66 million , including adverse development of $105 million in our homeowners lines and favorable development of $58 million in our personal excess lines as described above. 2016 For the three months ended September 30, 2016, net adverse PPD was $38 million , including $28 million adverse development in our homeowners and umbrella lines due to higher than expected loss emergence. Average loss severities were higher than expected, and to a lesser degree, reinsurance and other recoveries were lower than expected. For the nine months ended September 30, 2016, net adverse PPD was $20 million , due primarily to higher than expected loss emergence in our homeowners and umbrella lines as described above. North America Agricultural Insurance 2017 For the three months ended September 30, 2017 , net favorable PPD was $4 million across a number of accident years, none of which were significant individually or in the aggregate. For the nine months ended September 30, 2017 , net favorable PPD was $83 million . The majority of the claim development relates to our Multiple Peril Crop Insurance (MPCI) business and is favorable due to better than expected crop yield results in certain states at the prior year-end period (i.e., 2017 results based on crop yield results at year-end 2016). 2016 For the three months ended September 30, 2016, net favorable PPD was $11 million across a number of accident years, none of which were significant individually or in the aggregate. For the nine months ended September 30, 2016, net favorable PPD was $52 million . Actual claim development in the first quarter of 2016 for the 2015 crop year for MPCI business was favorable due to better than expected crop yield results in certain states at year-end 2015. Overseas General Insurance 2017 For the three months ended September 30, 2017 , net favorable PPD was $108 million , which was the net result of several underlying favorable and adverse movements, and was driven by the following principal changes: • Net favorable development of $109 million in long-tail business, primarily from: • Net favorable development of $40 million in casualty lines, with favorable development of $69 million in accident years 2013 and prior, resulting from lower than expected loss emergence, partially offset by adverse development of $29 million in accident years 2014 through 2016, primarily due to large loss experience in U.K. excess lines and wholesale business; and • Net favorable development of $34 million in financial lines, with favorable development of $124 million in accident years 2013 and prior, resulting from lower than expected loss emergence including favorable development on specific, litigated claims, and adverse development of $90 million in accident years 2014 through 2016, primarily due to large loss experience in specific Directors and Officers (D&O) portfolios in the U.K., Continental Europe, and Australia and Financial Institutions lines in the U.K. and Continental Europe. For the nine months ended September 30, 2017 , net favorable PPD was $184 million , which was the net result of several underlying favorable and adverse movements, and was driven by the following principal changes: • Net favorable development of $78 million in long-tail business, primarily from: • Favorable development of $34 million in financial lines, driven by the same factors as experienced for the three months ended September 30, 2017 as described above; and • Net favorable development of $9 million in casualty lines, driven by the same factors as experienced for the three months ended September 30, 2017, as described above, partially offset by adverse development of $32 million driven by a change in the discount rate in the U.K. (Ogden rate) impacting the 2016 and prior accident years. • Net favorable development of $106 million in short-tail business, primarily from: • Favorable development of $43 million in technical and energy lines, primarily from favorable loss emergence in accident years 2014 through 2016 primarily in offshore and power generation where experience has been better than expected; • Favorable development of $37 million in property and marine (excluding technical lines), primarily in accident years 2013 through 2015, driven mainly by favorable U.K. and Continental Europe loss emergence, including favorable claim-specific loss settlements; and • Favorable development of $20 million in A&H lines, primarily from favorable loss emergence in Asia Pacific and Continental Europe in accident years 2014 through 2016. 2016 For the three months ended September 30, 2016, net favorable PPD was $223 million , which was the net result of several underlying favorable and adverse movements, and was driven by the following principal changes: • Net favorable development of $234 million in long-tail business, primarily from: • Net favorable development of $167 million , primarily in casualty and financial lines, with favorable development of $261 million in accident years 2012 and prior, resulting from lower than expected loss emergence, and adverse development of $94 million in accident years 2013 to 2015, primarily due to large loss experience in our D&O portfolio in Asia and financial lines in Europe; • Favorable development of $28 million in aviation lines, impacting accident years 2012 and prior due to lower than expected loss emergence and case-specific reserve reductions; and • Favorable development of $25 million on an individual legacy liability case reserve take-down. This release follows a legal analysis completed in the third quarter of 2016, based on court opinion in the quarter and discussions with defense counsel, which concluded that these reserves were no longer required. • Adverse development of $11 million in short-tail business, none of which was significant individually or in the aggregate. For the nine months ended September 30, 2016, net favorable PPD was $338 million , which was the net result of several underlying favorable and adverse movements, and was driven by the following principal changes: • Net favorable development of $235 million in long-tail business due primarily to the same factors experienced for the three months ended September 30, 2016. • Net favorable development of $103 million in short-tail business primarily from: • Net favorable development of $66 million in property (including technical lines), primarily from favorable Continental Europe loss emergence in accident years 2012 through 2014; • Favorable development of $35 million in energy lines, primarily from a claims review of catastrophe impacts on underwriting years 2004 through 2008, as well as favorable loss emergence in accident years 2010 through 2014, primarily in offshore where experience on multi-year construction accounts has been better than expected; and Global Reinsurance 2017 For the three months ended September 30, 2017 , net favorable PPD was $41 million , which was the net result of several underlying favorable and adverse movements, and was driven by net favorable development of $29 million in our professional liability and medical malpractice lines primarily from treaty years 2013 and prior, principally resulting from lower than expected loss emergence in the U.S. portfolio. For the nine months ended September 30, 2017 , net favorable PPD was $64 million , which was the net result of several underlying favorable and adverse movements, and was driven by the following principal changes: • Net favorable development of $67 million on long-tail lines of business, primarily from: • Favorable development of $66 million in our casualty, professional liability and medical malpractice lines, primarily driven by the same factors as experienced for the three months ended September 30, 2017 as described above; and • Net adverse development of $10 million in our motor and excess liability lines, primarily due to adverse development of $9 million driven by a change in the discount rate in the U.K. (Ogden rate) primarily impacting the 2015 and prior treaty years. 2016 For the three months ended September 30, 2016, net favorable PPD was $28 million , primarily from net favorable development of $24 million in professional liability lines primarily impacting treaty years 2011 and prior due to lower than expected loss emergence. For the nine months ended September 30, 2016, net favorable PPD was $78 million , which was driven by the following principal changes: • Net favorable development of $41 million in casualty lines primarily impacting treaty years 2011 and prior, principally resulting from lower than expected loss emergence; and • Net favorable development of $30 million in professional liability lines due to the same factors experienced for the three months ended September 30, 2016, as described above. Corporate 2017 For the three months ended September 30, 2017 , adverse development was $87 million , driven principally by development of $77 million in environmental liabilities and $9 million for unallocated loss adjustment expenses due to run-off operating expenses paid and incurred in the respective periods, impacting the 1995 and prior accident years. The development in environmental liabilities was due to case specific settlements and both higher than expected remediation expense and defense costs. These higher costs impacted both large modeled accounts as well as smaller accounts. For the nine months ended September 30, 2017 , adverse development was $140 million , driven principally by development of environmental liabilities as described above, $35 million of development on run-off non-A&E casualty exposures due to higher than expected loss activity, and $28 million of unallocated loss adjustment expenses due to run-off operating expenses paid and incurred in the respective period. 2016 For the three months ended September 30, 2016, adverse development was $62 million , and was driven principally by development of $52 million in environmental liabilities and $10 million for unallocated loss adjustment expenses due to run-off operating expenses paid and incurred in the respective periods, impacting the 1995 and prior accident years. The development in environmental liabilities was due to case specific settlements and both higher than expected remediation expense and defense costs. These higher costs impacted both large modeled accounts as well as smaller accounts. For the nine months ended September 30, 2016, adverse development was $84 million , and was driven principally by development of environmental liabilities as described above and $27 million of unallocated loss adjustment expenses due to run-off operating expenses paid and incurred in the respective period.

Commitments, contingencies, and

Commitments, contingencies, and guarantees	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments, contingencies, and guarantees	Commitments, contingencies, and guarantees a) Derivative instruments Foreign currency management As a global company, Chubb entities transact business in multiple currencies. Our policy is to generally match assets, liabilities, and required capital for each individual jurisdiction in local currency, which would include the use of derivatives discussed below. We do not hedge our net asset non-U.S. dollar capital positions; however, we do consider hedging for planned cross border transactions. Derivative instruments employed Chubb maintains positions in derivative instruments such as futures, options, swaps, and foreign currency forward contracts for which the primary purposes are to manage duration and foreign currency exposure, yield enhancement, or to obtain an exposure to a particular financial market. Chubb also maintains positions in convertible securities that contain embedded derivatives. Investment derivative instruments are recorded in either Other assets (OA) or Accounts payable, accrued expenses, and other liabilities (AP), convertible bonds are recorded in Fixed maturities available for sale (FM AFS), and convertible equity securities are recorded in Equity securities (ES) in the Consolidated balance sheets. These are the most numerous and frequent derivative transactions. In addition, Chubb from time to time purchases to be announced mortgage-backed securities (TBAs) as part of its investing activities. Under reinsurance programs covering GLBs, Chubb assumes the risk of GLBs, including GMIB and GMAB, associated with variable annuity contracts. The GMIB risk is triggered if, at the time the contract holder elects to convert the accumulated account value to a periodic payment stream (annuitize), the accumulated account value is not sufficient to provide a guaranteed minimum level of monthly income. The GMAB risk is triggered if, at contract maturity, the contract holder’s account value is less than a guaranteed minimum value. The GLB reinsurance product meets the definition of a derivative instrument. Benefit reserves in respect of GLBs are classified as Future policy benefits (FPB) while the fair value derivative adjustment is classified within AP. Chubb also generally maintains positions in exchange-traded equity futures contracts on equity market indices to limit equity exposure in the GMDB and GLB blocks of business. All derivative instruments are carried at fair value with changes in fair value recorded in Net realized gains (losses) in the Consolidated statements of operations. None of the derivative instruments are designated as hedges for accounting purposes. The following table presents the balance sheet locations, fair values of derivative instruments in an asset or (liability) position, and notional values/payment provisions of our derivative instruments: September 30, 2017 December 31, 2016 Consolidated Balance Sheet Location Fair Value Notional Value/ Payment Provision Fair Value Notional Value/ Payment Provision (in millions of U.S. dollars) Derivative Asset Derivative (Liability) Derivative Asset Derivative (Liability) Investment and embedded derivative instruments: Foreign currency forward contracts OA / (AP) $ 8 $ (31 ) $ 2,035 $ 25 $ (50 ) $ 2,220 Cross-currency swaps OA / (AP) — — 45 — — 95 Options/Futures contracts on notes and bonds OA / (AP) 7 (6 ) 1,437 6 (4 ) 2,344 Convertible securities (1) FM AFS / ES — — 4 2 — 7 $ 15 $ (37 ) $ 3,521 $ 33 $ (54 ) $ 4,666 Other derivative instruments: Futures contracts on equities (2) OA / (AP) $ — $ (25 ) $ 1,455 $ 1 $ — $ 1,316 Other OA / (AP) — (2 ) 259 2 (13 ) 214 $ — $ (27 ) $ 1,714 $ 3 $ (13 ) $ 1,530 GLB (3) (AP) / (FPB) $ — $ (635 ) $ 1,138 $ — $ (853 ) $ 1,264 (1) Includes fair value of embedded derivatives. (2) Related to GMDB and GLB blocks of business. (3) Includes both future policy benefits reserves and fair value derivative adjustment. Note that the payment provision related to GLB is the net amount at risk. The concept of a notional value does not apply to the GLB reinsurance contracts. At September 30, 2017 and December 31, 2016, derivative liabilities of $41 million and $10 million , respectively, included in the table above were subject to a master netting agreement. The remaining derivatives included in the table above were not subject to a master netting agreement. b) Secured borrowings Chubb participates in a securities lending program operated by a third-party banking institution whereby certain assets are loaned to qualified borrowers and from which we earn an incremental return. The securities lending collateral can only be drawn down by Chubb in the event that the institution borrowing the securities is in default under the lending agreement. An indemnification agreement with the lending agent protects us in the event a borrower becomes insolvent or fails to return any of the securities on loan. The collateral is recorded in Securities lending collateral and the liability is recorded in Securities lending payable in the Consolidated balance sheets. Potential risks exist in our secured borrowing transactions due to market conditions and counterparty exposure. With collateral that we pledge, there is a risk that the collateral may not be returned at the expiration of the agreement. If the counterparty fails to return the collateral, Chubb will have free use of the borrowed funds until our collateral is returned. In addition, we may encounter the risk that Chubb may not be able to renew outstanding borrowings with a new term or with an existing counterparty due to market conditions including a decrease in demand as well as more restrictive terms from banks due to increased regulatory and capital constraints. Should this condition occur, Chubb may seek alternative borrowing sources or reduce borrowings. Additionally, increased margins and collateral requirements due to market conditions would increase our restricted assets as we are required to provide additional collateral to support the transaction. The following table presents the carrying value of collateral held under securities lending agreements by investment category and remaining contractual maturity of the underlying agreements: Remaining contractual maturity September 30 December 31 2017 2016 (in millions of U.S. dollars) Overnight and Continuous Collateral held under securities lending agreements: Cash $ 1,109 $ 423 U.S. Treasury and agency 38 54 Foreign 491 578 Corporate securities — 37 Mortgage-backed securities 46 — Equity securities 73 — $ 1,757 $ 1,092 Gross amount of recognized liability for securities lending payable $ 1,757 $ 1,093 Difference (1) $ — $ (1 ) (1) The carrying value of the securities lending collateral held is $ 1 million lower than the securities lending payable at December 31, 2016 due to accrued interest recorded in the securities lending payable. At September 30, 2017 and December 31, 2016, our repurchase agreement obligations of $1,408 million and $1,403 million , respectively, were fully collateralized. In contrast to securities lending programs, the use of cash received is not restricted for the repurchase obligations. The fair value of the underlying securities sold remains in Fixed maturities available for sale and Equity securities and the repurchase agreement obligation is recorded in Repurchase agreements in the Consolidated balance sheets. The following table presents the carrying value of collateral pledged under repurchase agreements by investment category and remaining contractual maturity of the underlying agreements: Remaining contractual maturity September 30, 2017 December 31, 2016 Up to 30 Days Greater than 90 Days Total Up to 30 Days Greater than 90 Days Total (in millions of U.S. dollars) Collateral pledged under repurchase agreements: Cash $ — $ — $ — $ — $ 1 $ 1 U.S. Treasury and agency 231 9 240 230 10 240 Mortgage-backed securities 343 858 1,201 339 881 1,220 $ 574 $ 867 $ 1,441 $ 569 $ 892 $ 1,461 Gross amount of recognized liabilities for repurchase agreements $ 1,408 $ 1,403 Difference (1) $ 33 $ 58 (1) Per the repurchase agreements, the amount of collateral posted is required to exceed the amount of gross liability. The following table presents net realized gains (losses) related to derivative instrument activity in the Consolidated statements of operations: Three Months Ended Nine Months Ended September 30 September 30 (in millions of U.S. dollars) 2017 2016 2017 2016 Investment and embedded derivative instruments: Foreign currency forward contracts $ (7 ) $ (10 ) $ — $ (30 ) All other futures contracts and options (8 ) 8 (25 ) (63 ) Convertible securities (1) 1 3 1 8 Total investment and embedded derivative instruments $ (14 ) $ 1 $ (24 ) $ (85 ) GLB and other derivative instruments: GLB (2) $ 54 $ 89 $ 265 $ (270 ) Futures contracts on equities (3) (57 ) (45 ) (169 ) (88 ) Other (5 ) 3 (4 ) 1 Total GLB and other derivative instruments $ (8 ) $ 47 $ 92 $ (357 ) $ (22 ) $ 48 $ 68 $ (442 ) (1) Includes embedded derivatives. (2) Excludes foreign exchange gains (losses) related to GLB. (3) Related to GMDB and GLB blocks of business. c) Derivative instrument objectives (i) Foreign currency exposure management A foreign currency forward contract (forward) is an agreement between participants to exchange specific foreign currencies at a future date. Chubb uses forwards to minimize the effect of fluctuating foreign currencies as discussed above. (ii) Duration management and market exposure Futures Futures contracts give the holder the right and obligation to participate in market movements, determined by the index or underlying security on which the futures contract is based. Settlement is made daily in cash by an amount equal to the change in value of the futures contract times a multiplier that scales the size of the contract. Exchange-traded futures contracts on money market instruments, notes, and bonds are used in fixed maturity portfolios to more efficiently manage duration, as substitutes for ownership of the money market instruments, bonds, and notes without significantly increasing the risk in the portfolio. Investments in futures contracts may be made only to the extent that there are assets under management not otherwise committed. Exchange-traded equity futures contracts are used to limit exposure to a severe equity market decline, which would cause an increase in expected claims and therefore, an increase in reserves for GMDB and GLB reinsurance business. Options An option contract conveys to the holder the right, but not the obligation, to purchase or sell a specified amount or value of an underlying security at a fixed price. Option contracts are used in the investment portfolio as protection against unexpected shifts in interest rates, which would affect the duration of the fixed maturity portfolio. By using options in the portfolio, the overall interest rate sensitivity of the portfolio can be reduced. Option contracts may also be used as an alternative to futures contracts in the synthetic strategy as described above. The price of an option is influenced by the underlying security, expected volatility, time to expiration, and supply and demand. The credit risk associated with the above derivative financial instruments relates to the potential for non-performance by counterparties. Although non-performance is not anticipated, in order to minimize the risk of loss, management monitors the creditworthiness of its counterparties and obtains collateral. The performance of exchange-traded instruments is guaranteed by the exchange on which they trade. For non-exchange-traded instruments, the counterparties are principally banks which must meet certain criteria according to our investment guidelines. Cross-currency swaps Cross-currency swaps are agreements under which two counterparties exchange interest payments and principal denominated in different currencies at a future date. We use cross-currency swaps to reduce the foreign currency and interest rate risk by converting cash flows back into local currency. We invest in foreign currency denominated investments to improve credit diversification and also to obtain better duration matching to our liabilities that is limited in the local currency market. Other Included within Other are derivatives intended to reduce potential losses which may arise from certain exposures in our insurance business. The economic benefit provided by these derivatives is similar to purchased reinsurance. For example, Chubb may enter into crop derivative contracts to protect underwriting results in the event of a significant decline in commodity prices. (iii) Convertible security investments A convertible security is a debt instrument or preferred stock that can be converted into a predetermined amount of the issuer’s equity. The convertible option is an embedded derivative within the host instruments which are classified in the investment portfolio as either available for sale or as an equity security. Chubb purchases convertible securities for their total return and not specifically for the conversion feature. (iv) TBA By acquiring TBAs, we make a commitment to purchase a future issuance of mortgage-backed securities. For the period between purchase of the TBAs and issuance of the underlying security, we account for our position as a derivative in the consolidated financial statements. Chubb purchases TBAs both for their total return and for the flexibility they provide related to our mortgage-backed security strategy. (v) GLB Under the GLB program, as the assuming entity, Chubb is obligated to provide coverage until the expiration or maturity of the underlying deferred annuity contracts or the expiry of the reinsurance treaty. Premiums received under the reinsurance treaties are classified as premium. Expected losses allocated to premiums received are classified as Future policy benefits and valued similar to GMDB reinsurance. Other changes in fair value, principally arising from changes in expected losses allocated to expected future premiums, are classified as Net realized gains (losses). Fair value represents management’s estimate of an exit price and thus, includes a risk margin. We may recognize a realized loss for other changes in fair value due to adverse changes in the capital markets (e.g., declining interest rates and/or declining equity markets) and changes in actual or estimated future policyholder behavior (e.g., increased annuitization or decreased lapse rates) although we expect the business to be profitable. We believe this presentation provides the most meaningful disclosure of changes in the underlying risk within the GLB reinsurance programs for a given reporting period. d) Fixed maturities At September 30, 2017 , we have commitments to purchase fixed income securities of $932 million over the next several years. e) Other investments At September 30, 2017 , included in Other investments in the Consolidated balance sheets are investments in limited partnerships and partially-owned investment companies with a carrying value of $3.4 billion. In connection with these investments, we have commitments that may require funding of up to $1.7 billion over the next several years. In October 2017, we entered into a new limited partnership arrangement which may require funding of up to $2.5 billion over the next five years. f) Taxation At September 30, 2017 , $14 million of unrecognized tax benefits remain outstanding. It is reasonably possible that over the next twelve months, the amount of unrecognized tax benefits may change resulting from the re-evaluation of unrecognized tax benefits arising from examinations of taxing authorities and the closing of tax statute limitations. With few exceptions, Chubb is no longer subject to state and local or non-U.S. income tax examinations for years before 2010. g) Letters of credit On October 25, 2017, we replaced our $1.5 billion letter of credit/revolver facility that was set to expire in November 2017 with an amended and restated credit facility that provides for up to $1.0 billion of availability, all of which may be used for the issuance of letters of credit and for revolving loans. We have the ability to increase the capacity under our existing credit facility to $2.0 billion under certain conditions, but any such increase would not raise the sub-limit for revolving loans above $1.0 billion . The letter of credit facility required that we maintain certain financial covenants, all of which we met at September 30, 2017 and at the time of renewal. h) Legal proceedings Our insurance subsidiaries are subject to claims litigation involving disputed interpretations of policy coverages and, in some jurisdictions, direct actions by allegedly-injured persons seeking damages from policyholders. These lawsuits, involving claims on policies issued by our subsidiaries which are typical to the insurance industry in general and in the normal course of business, are considered in our loss and loss expense reserves. In addition to claims litigation, we are subject to lawsuits and regulatory actions in the normal course of business that do not arise from or directly relate to claims on insurance policies. This category of business litigation typically involves, among other things, allegations of underwriting errors or misconduct, employment claims, regulatory activity, or disputes arising from our business ventures. In the opinion of management, our ultimate liability for these matters could be, but we believe is not likely to be, material to our consolidated financial condition and results of operations.

Shareholders' equity

Shareholders' equity	9 Months Ended
	Sep. 30, 2017
Stockholders' Equity Note [Abstract]
Shareholders' equity	Shareholders’ equity All of Chubb’s Common Shares are authorized under Swiss corporate law. Though the par value of Common Shares is stated in Swiss francs, Chubb continues to use U.S. dollars as its reporting currency for preparing consolidated financial statements. Under Swiss corporate law, dividends, including distributions through a reduction in par value (par value reduction) or from legal reserves, must be stated in Swiss francs though dividend payments are made by Chubb in U.S. dollars. At September 30, 2017, our Common Shares had a par value of CHF 24.15 per share. At our May 2016 and 2015 annual general meetings, our shareholders approved an annual dividend for the following year of up to $ 2.76 per share and $ 2.68 per share, respectively, which were paid in four quarterly installments of $ 0.69 per share and $ 0.67 per share, respectively, at dates determined by the Board of Directors (Board) after the annual general meetings by way of a distribution from capital contribution reserves, transferred to free reserves for payment. At our May 2017 annual general meeting, our shareholders approved an annual dividend for the following year of up to $2.84 per share, expected to be paid in four quarterly installments of $0.71 per share after the annual general meeting by way of distribution from capital contribution reserves, transferred to free reserves for payment. The Board will determine the record and payment dates at which the annual dividend may be paid until the date of the 2018 annual general meeting, and is authorized to abstain from distributing a dividend at its discretion. The following table presents dividend distributions per Common Share in Swiss francs (CHF) and U.S. dollars (USD): Three Months Ended Nine Months Ended September 30 September 30 2017 2016 2017 2016 CHF USD CHF USD CHF USD CHF USD Total dividend distributions per common share 0.68 $ 0.71 0.67 $ 0.69 2.06 $ 2.11 2.01 $ 2.05 Common Shares in treasury are used principally for issuance upon the exercise of employee stock options, grants of restricted stock, and purchases under the Employee Stock Purchase Plan (ESPP). At September 30, 2017 , 15,625,345 Common Shares remain in treasury after net shares redeemed under employee share-based compensation plans. Chubb Limited securities repurchase authorization There was no share repurchase program from January 2016 through October 2016. In November 2016, the Board authorized a share repurchase program of $1.0 billion of Chubb's Common Shares through December 31, 2017. Repurchases of Chubb's Common Shares conducted in a series of open market transactions from January 1, 2017 through October 31, 2017 under the Board authorization are as follows: (in millions of U.S. dollars, except share data) Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 October 1, 2017 through October 31, 2017 Number of shares repurchased 1,615,383 5,033,013 25,000 Cost of shares repurchased $ 232 $ 707 $ 4 Repurchase authorization remaining at end of period $ 293 $ 293 $ 289

Share-based compensation

Share-based compensation	9 Months Ended
	Sep. 30, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based compensation	Share-based compensation The Chubb Limited 2016 Long-Term Incentive Plan (the 2016 LTIP) permits grants of incentive and non-qualified stock options; restricted stock and restricted stock units; and performance-based restricted stock awards. The incentive and non-qualified stock options are granted principally at an option price per share equal to the grant date fair value of Chubb's Common Shares. Stock options are generally granted with a 3-year vesting period and a 10-year term and typically vest in equal annual installments over the vesting period, which is also the requisite service period. On February 23, 2017 , Chubb granted 2,065,620 stock options with a weighted-average grant date fair value of $22.97 each estimated using the Black-Scholes option pricing model. The service-based restricted stock and restricted stock units are generally granted with a 4-year vesting period, based on a graded vesting schedule. Performance-based restricted stock awards granted prior to January 2017 comprised target awards which have four installments that vest annually based on tangible book value (shareholders' equity less goodwill and intangible assets, net of tax) per share growth compared to a defined group of peer companies, and premium awards, which are earned only if tangible book value per share growth over the cumulative 4-year period after the grant of the associated target awards exceeds a higher threshold compared to our peer group. The terms of performance-based restricted stock awards granted beginning in January 2017 were updated to now include a 3-year cliff vesting provision in place of the 4-year graded vesting period. In addition, these awards now include an additional vesting criteria based on the P&C combined ratio compared to a defined group of peer companies as well as an additional vesting provision for premium awards based on total shareholder return (TSR) compared to a defined group of peer companies. Chubb's restricted stock is granted at market close price on the grant date. On February 23, 2017 , Chubb granted 1,105,118 service-based restricted stock awards, 326,272 service-based restricted stock units, and 202,251 performance-based stock awards to employees and officers with a grant date fair value of $139.01 each. Each restricted stock unit represents our obligation to deliver to the holder one Common Share upon vesting.

Postretirement benefits Postret

Postretirement benefits Postretirement benefits	9 Months Ended
	Sep. 30, 2017
Retirement Benefits [Abstract]
Compensation and Employee Benefit Plans [Text Block]	Postretirement benefits The components of net pension and other postretirement benefit costs (benefits) reflected in Net income in the Consolidated statements of operations were as follows: Three Months Ended September 30 Pension Benefits Other Postretirement Benefits U.S. Plans Non-U.S. Plans Total U.S. Plans Non-U.S. Plans Total (in millions of U.S. dollars) 2017 Service cost $ 15 $ 6 $ 21 $ — $ — $ — Interest cost 27 6 33 1 1 2 Expected return on plan assets (47 ) (11 ) (58 ) (2 ) — (2 ) Amortization of net actuarial loss — 1 1 — — — Amortization of prior service cost — — — (22 ) — (22 ) Curtailments — — — (32 ) — (32 ) Net periodic (benefit) cost $ (5 ) $ 2 $ (3 ) $ (55 ) $ 1 $ (54 ) 2016 Service cost $ 20 $ 6 $ 26 $ 4 $ — $ 4 Interest cost 26 8 34 4 — 4 Expected return on plan assets (42 ) (10 ) (52 ) (3 ) — (3 ) Amortization of net actuarial loss — — — — — — Curtailments (4 ) — (4 ) — — — Settlements (1 ) — (1 ) — — — Net periodic (benefit) cost $ (1 ) $ 4 $ 3 $ 5 $ — $ 5 Nine Months Ended September 30 Pension Benefits Other Postretirement Benefits U.S. Plans Non-U.S. Plans Total U.S. Plans Non-U.S. Plans Total (in millions of U.S. dollars) 2017 Service cost $ 47 $ 14 $ 61 $ 1 $ 1 $ 2 Interest cost 79 20 99 2 1 3 Expected return on plan assets (142 ) (31 ) (173 ) (4 ) — (4 ) Amortization of net actuarial loss — 2 2 — — — Amortization of prior service cost — — — (68 ) — (68 ) Curtailments — (8 ) (8 ) (32 ) — (32 ) Net periodic (benefit) cost $ (16 ) $ (3 ) $ (19 ) $ (101 ) $ 2 $ (99 ) 2016 Service cost $ 57 $ 15 $ 72 $ 8 $ 1 $ 9 Interest cost 80 24 104 13 — 13 Expected return on plan assets (121 ) (30 ) (151 ) (7 ) — (7 ) Amortization of net actuarial loss — 2 2 — — — Curtailments (4 ) — (4 ) — — — Settlements (1 ) — (1 ) — — — Net periodic cost $ 11 $ 11 $ 22 $ 14 $ 1 $ 15

Segment information

Segment information	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Segment information	Segment information Chubb operates through six business segments: North America Commercial P&C Insurance, North America Personal P&C Insurance, North America Agricultural Insurance, Overseas General Insurance, Global Reinsurance, and Life Insurance. Corporate primarily includes loss and loss expenses of asbestos and environmental (A&E) run-off liabilities, and the results of our non-insurance companies including Chubb Limited, Chubb Group Management and Holdings Ltd, and Chubb INA Holdings Inc. Our exposure to A&E claims principally arises out of liabilities acquired when we purchased Westchester Specialty in 1998, CIGNA’s P&C business in 1999, and legacy Chubb Corp run-off business in 2016. For segment reporting purposes, certain items are presented in a different manner below than in the consolidated financial statements. Management uses underwriting income as the main measures of segment performance. Chubb calculates underwriting income by subtracting Losses and loss expenses, Policy benefits, Policy acquisition costs, and Administrative expenses from Net premiums earned. To calculate segment income, include Net investment income, Other (income) expense, and Amortization of purchased intangibles. For the North America Agricultural Insurance segment, management includes gains and losses on crop derivatives as a component of underwriting income. For example, for the three months ended September 30, 2017, underwriting income in our North America Agricultural Insurance segment was $86 million . This amount includes $5 million of realized losses related to crop derivatives which are reported in Net realized gains (losses) in the Corporate column below. For the Life Insurance segment, management includes Net investment income and (Gains) losses from fair value changes in separate account assets that do not qualify for separate account reporting under GAAP as components of Life Insurance underwriting income. For example, for the three months ended September 30, 2017, Life Insurance underwriting income of $70 million includes Net investment income of $78 million and gains from fair value changes in separate account assets of $24 million . The gains from fair value changes in separate account assets are reported in Other (income) expense in the table below. The following tables present the Statement of Operations by segment: North America Commercial P&C Insurance North America Personal P&C Insurance North America Agricultural Insurance Overseas General Insurance Global Reinsurance Life Insurance Corporate Chubb Consolidated For the Three Months Ended September 30, 2017 (in millions of U.S. dollars) Net premiums written $ 3,089 $ 1,194 $ 926 $ 1,963 $ 191 $ 539 $ — $ 7,902 Net premiums earned 3,016 1,117 898 2,064 185 527 — 7,807 Losses and loss expenses 2,580 1,062 759 1,281 295 181 89 6,247 Policy benefits — — — — — 169 — 169 Policy acquisition costs 469 226 49 569 43 132 — 1,488 Administrative expenses 256 61 (1 ) 246 11 77 64 714 Underwriting income (loss) (289 ) (232 ) 91 (32 ) (164 ) (32 ) (153 ) (811 ) Net investment income (loss) 497 57 6 164 80 78 (69 ) 813 Other (income) expense (4 ) 1 — (10 ) (3 ) (19 ) (83 ) (118 ) Amortization expense of purchased intangibles — 4 8 11 — 1 41 65 Segment income (loss) $ 212 $ (180 ) $ 89 $ 131 $ (81 ) $ 64 $ (180 ) $ 55 Net realized gains (losses) including OTTI (10 ) (10 ) Interest expense 150 150 Chubb integration expenses 50 50 Income tax benefit (85 ) (85 ) Net loss $ (305 ) $ (70 ) North America Commercial P&C Insurance North America Personal P&C Insurance North America Agricultural Insurance Overseas General Insurance Global Reinsurance Life Insurance Corporate Chubb Consolidated For the Three Months Ended September 30, 2016 (in millions of U.S. dollars) Net premiums written $ 3,110 $ 1,011 $ 849 $ 1,940 $ 131 $ 532 $ — $ 7,573 Net premiums earned 3,086 1,081 819 2,034 156 512 — 7,688 Losses and loss expenses 1,863 594 683 843 49 174 63 4,269 Policy benefits — — — — — 155 — 155 Policy acquisition costs 522 229 48 546 42 127 — 1,514 Administrative expenses 275 89 1 261 12 77 57 772 Underwriting income (loss) 426 169 87 384 53 (21 ) (120 ) 978 Net investment income (loss) 477 53 5 152 67 71 (86 ) 739 Other (income) expense 3 2 — (6 ) — (20 ) (70 ) (91 ) Amortization expense (benefit) of purchased intangibles — 4 7 12 — 1 (20 ) 4 Segment income (loss) $ 900 $ 216 $ 85 $ 530 $ 120 $ 69 $ (116 ) $ 1,804 Net realized gains (losses) including OTTI 100 100 Interest expense 152 152 Chubb integration expenses 115 115 Income tax expense 277 277 Net income (loss) $ (560 ) $ 1,360 North America Commercial P&C Insurance North America Personal P&C Insurance North America Agricultural Insurance Overseas General Insurance Global Reinsurance Life Insurance Corporate Chubb Consolidated For the Nine Months Ended September 30, 2017 (in millions of U.S. dollars) Net premiums written $ 9,035 $ 3,433 $ 1,390 $ 6,169 $ 580 $ 1,586 $ — $ 22,193 Net premiums earned 9,156 3,296 1,256 6,018 542 1,548 — 21,816 Losses and loss expenses 6,376 2,378 976 3,316 435 556 145 14,182 Policy benefits — — — — — 500 — 500 Policy acquisition costs 1,420 673 75 1,653 137 376 — 4,334 Administrative expenses 728 192 (4 ) 734 33 226 187 2,096 Underwriting income (loss) 632 53 209 315 (63 ) (110 ) (332 ) 704 Net investment income (loss) 1,465 168 18 460 207 230 (220 ) 2,328 Other (income) expense (4 ) 3 1 (14 ) (2 ) (60 ) (257 ) (333 ) Amortization expense of purchased intangibles — 12 22 33 — 2 125 194 Segment income (loss) $ 2,101 $ 206 $ 204 $ 756 $ 146 $ 178 $ (420 ) $ 3,171 Net realized gains (losses) including OTTI 84 84 Interest expense 451 451 Chubb integration expenses 233 233 Income tax expense 243 243 Net income (loss) $ (1,263 ) $ 2,328 North America Commercial P&C Insurance North America Personal P&C Insurance North America Agricultural Insurance Overseas General Insurance Global Reinsurance Life Insurance Corporate Chubb Consolidated For the Nine Months Ended September 30, 2016 (in millions of U.S. dollars) Net premiums written $ 8,657 $ 3,113 $ 1,288 $ 6,012 $ 562 $ 1,575 $ — $ 21,207 Net premiums earned 9,130 3,245 1,169 6,082 543 1,521 — 21,690 Losses and loss expenses 5,581 1,916 937 2,953 225 498 87 12,197 Policy benefits — — — — — 427 — 427 Policy acquisition costs 1,549 747 77 1,586 142 386 — 4,487 Administrative expenses 840 275 (1 ) 801 40 226 192 2,373 Underwriting income (loss) 1,160 307 156 742 136 (16 ) (279 ) 2,206 Net investment income (loss) 1,371 155 15 445 199 207 (271 ) 2,121 Other (income) expense (6 ) 6 — (16 ) (3 ) (14 ) (59 ) (92 ) Amortization expense (benefit) of purchased intangibles — 16 22 36 — 2 (60 ) 16 Segment income (loss) $ 2,537 $ 440 $ 149 $ 1,167 $ 338 $ 203 $ (431 ) $ 4,403 Net realized gains (losses) including OTTI (510 ) (510 ) Interest expense 451 451 Chubb integration expenses 361 361 Income tax expense 556 556 Net income (loss) $ (2,309 ) $ 2,525 Underwriting assets are reviewed in total by management for purposes of decision-making. Other than Unpaid losses and loss expenses, Reinsurance recoverables, Goodwill and Other intangible assets, Chubb does not allocate assets to its segments.

Earnings per share

Earnings per share	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Earnings per share	Earnings per share Three Months Ended Nine Months Ended September 30 September 30 (in millions of U.S. dollars, except share and per share data) 2017 2016 2017 2016 Numerator: Net income (loss) $ (70 ) $ 1,360 $ 2,328 $ 2,525 Denominator: Denominator for basic earnings per share: Weighted-average shares outstanding 466,370,784 468,021,093 467,658,334 460,631,794 Denominator for diluted earnings per share: Share-based compensation plans — 3,375,269 3,961,572 3,439,017 Weighted-average shares outstanding and assumed conversions 466,370,784 471,396,362 471,619,906 464,070,811 Basic earnings (loss) per share $ (0.15 ) $ 2.90 $ 4.98 $ 5.48 Diluted earnings (loss) per share $ (0.15 ) $ 2.88 $ 4.94 $ 5.44 Potential anti-dilutive share conversions 2,045,829 1,306,710 1,673,777 1,635,337 Excluded from weighted-average shares outstanding and assumed conversions is the impact of securities that would have been anti-dilutive during the respective periods. In addition, for the three months ended September 30, 2017, weighted-average shares outstanding used in calculating diluted loss per share excludes the effect of dilutive securities of 3,820,673 shares. In periods where a net loss is recognized, inclusion of incremental dilution is antidilutive.

Information provided in connect

Information provided in connection with outstanding debt of subsidiaries	9 Months Ended
	Sep. 30, 2017
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Abstract]
Information provided in connection with outstanding debt of subsidiaries	Information provided in connection with outstanding debt of subsidiaries The following tables present condensed consolidating financial information at September 30, 2017 and December 31, 2016 , and for the three and nine months ended September 30, 2017 and 2016 for Chubb Limited (Parent Guarantor) and Chubb INA Holdings Inc. (Subsidiary Issuer). The Subsidiary Issuer is an indirect 100 percent-owned subsidiary of the Parent Guarantor. The Parent Guarantor fully and unconditionally guarantees certain of the debt of the Subsidiary Issuer. Condensed consolidating financial information of the Parent Guarantor and Subsidiary Issuer are presented on the equity method of accounting. The revenues and expenses and cash flows of the subsidiaries of the Subsidiary Issuer are presented in the Other Chubb Limited Subsidiaries column on a combined basis. Condensed Consolidating Balance Sheet at September 30, 2017 (in millions of U.S. dollars) Chubb Limited (Parent Guarantor) Chubb INA Holdings Inc. (Subsidiary Issuer) Other Chubb Limited Subsidiaries Consolidating Adjustments and Eliminations Chubb Limited Consolidated Assets Investments $ — $ 169 $ 102,255 $ — $ 102,424 Cash (1) 1 — 1,174 (87 ) 1,088 Insurance and reinsurance balances receivable — — 11,076 (1,525 ) 9,551 Reinsurance recoverable on losses and loss expenses — — 27,007 (12,208 ) 14,799 Reinsurance recoverable on policy benefits — — 1,232 (1,039 ) 193 Value of business acquired — — 339 — 339 Goodwill and other intangible assets — — 22,265 — 22,265 Investments in subsidiaries 40,936 50,926 — (91,862 ) — Due from subsidiaries and affiliates, net 9,913 — — (9,913 ) — Other assets 61 276 20,699 (4,117 ) 16,919 Total assets $ 50,911 $ 51,371 $ 186,047 $ (120,751 ) $ 167,578 Liabilities Unpaid losses and loss expenses $ — $ — $ 75,688 $ (11,535 ) $ 64,153 Unearned premiums — — 19,150 (3,694 ) 15,456 Future policy benefits — — 6,346 (1,039 ) 5,307 Due to subsidiaries and affiliates, net — 9,697 216 (9,913 ) — Affiliated notional cash pooling programs (1) 85 2 — (87 ) — Repurchase agreements — — 1,408 — 1,408 Short-term debt — 1,020 — — 1,020 Long-term debt — 11,548 11 — 11,559 Trust preferred securities — 308 — — 308 Other liabilities 355 1,685 18,477 (2,621 ) 17,896 Total liabilities 440 24,260 121,296 (28,889 ) 117,107 Total shareholders’ equity 50,471 27,111 64,751 (91,862 ) 50,471 Total liabilities and shareholders’ equity $ 50,911 $ 51,371 $ 186,047 $ (120,751 ) $ 167,578 (1) Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At September 30, 2017 , the cash balance of one or more entities was negative; however, the overall Pool balances were positive. Condensed Consolidating Balance Sheet at December 31, 2016 (in millions of U.S. dollars) Chubb Limited (Parent Guarantor) Chubb INA Holdings Inc. (Subsidiary Issuer) Other Chubb Limited Subsidiaries Consolidating Adjustments and Eliminations Chubb Limited Consolidated Assets Investments $ 27 $ 485 $ 98,582 $ — $ 99,094 Cash (1) 1 1 1,965 (982 ) 985 Insurance and reinsurance balances receivable — — 10,498 (1,528 ) 8,970 Reinsurance recoverable on losses and loss expenses — — 24,496 (10,919 ) 13,577 Reinsurance recoverable on policy benefits — — 1,153 (971 ) 182 Value of business acquired — — 355 — 355 Goodwill and other intangible assets — — 22,095 — 22,095 Investments in subsidiaries 38,408 49,509 — (87,917 ) — Due from subsidiaries and affiliates, net 10,482 — — (10,482 ) — Other assets 3 436 18,442 (4,353 ) 14,528 Total assets $ 48,921 $ 50,431 $ 177,586 $ (117,152 ) $ 159,786 Liabilities Unpaid losses and loss expenses $ — $ — $ 70,683 $ (10,143 ) $ 60,540 Unearned premiums — — 18,538 (3,759 ) 14,779 Future policy benefits — — 6,007 (971 ) 5,036 Due to subsidiaries and affiliates, net — 10,209 273 (10,482 ) — Affiliated notional cash pooling programs (1) 363 619 — (982 ) — Repurchase agreements — — 1,403 — 1,403 Short-term debt — 500 — — 500 Long-term debt — 12,599 11 — 12,610 Trust preferred securities — 308 — — 308 Other liabilities 283 1,582 17,368 (2,898 ) 16,335 Total liabilities 646 25,817 114,283 (29,235 ) 111,511 Total shareholders’ equity 48,275 24,614 63,303 (87,917 ) 48,275 Total liabilities and shareholders’ equity $ 48,921 $ 50,431 $ 177,586 $ (117,152 ) $ 159,786 (1) Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At December 31, 2016 , the cash balance of one or more entities was negative; however, the overall Pool balances were positive. Condensed Consolidating Statements of Operations and Comprehensive Income For the Three Months Ended September 30, 2017 Chubb Limited (Parent Guarantor) Chubb INA Holdings Inc. (Subsidiary Issuer) Other Chubb Limited Subsidiaries Consolidating Adjustments and Eliminations Chubb Limited Consolidated (in millions of U.S. dollars) Net premiums written $ — $ — $ 7,902 $ — $ 7,902 Net premiums earned — — 7,807 — 7,807 Net investment income 1 3 809 — 813 Equity in earnings of subsidiaries (127 ) 212 — (85 ) — Net realized gains (losses) including OTTI — (8 ) (2 ) — (10 ) Losses and loss expenses — — 6,247 — 6,247 Policy benefits — — 169 — 169 Policy acquisition costs and administrative expenses 20 16 2,166 — 2,202 Interest (income) expense (84 ) 208 26 — 150 Other (income) expense (5 ) 9 (122 ) — (118 ) Amortization of purchased intangibles — — 65 — 65 Chubb integration expenses 7 1 42 — 50 Income tax expense (benefit) 6 (89 ) (2 ) — (85 ) Net income (loss) $ (70 ) $ 62 $ 23 $ (85 ) $ (70 ) Comprehensive income $ 629 $ 748 $ 724 $ (1,472 ) $ 629 Condensed Consolidating Statements of Operations and Comprehensive Income For the Three Months Ended September 30, 2016 Chubb Limited (Parent Guarantor) Chubb INA Holdings Inc. (Subsidiary Issuer) Other Chubb Limited Subsidiaries Consolidating Adjustments and Eliminations Chubb Limited Consolidated (in millions of U.S. dollars) Net premiums written $ — $ — $ 7,573 $ — $ 7,573 Net premiums earned — — 7,688 — 7,688 Net investment income 1 2 736 — 739 Equity in earnings of subsidiaries 1,292 748 — (2,040 ) — Net realized gains (losses) including OTTI — (2 ) 102 — 100 Losses and loss expenses — — 4,269 — 4,269 Policy benefits — — 155 — 155 Policy acquisition costs and administrative expenses 15 12 2,259 — 2,286 Interest (income) expense (93 ) 233 12 — 152 Other (income) expense (7 ) 6 (90 ) — (91 ) Amortization of purchased intangibles — — 4 — 4 Chubb integration expenses 12 16 87 — 115 Income tax expense (benefit) 6 (136 ) 407 — 277 Net income $ 1,360 $ 617 $ 1,423 $ (2,040 ) $ 1,360 Comprehensive income $ 1,376 $ 627 $ 1,439 $ (2,066 ) $ 1,376 Condensed Consolidating Statements of Operations and Comprehensive Income For the Nine Months Ended September 30, 2017 Chubb Limited (Parent Guarantor) Chubb INA Holdings Inc. (Subsidiary Issuer) Other Chubb Limited Subsidiaries Consolidating Adjustments and Eliminations Chubb Limited Consolidated (in millions of U.S. dollars) Net premiums written $ — $ — $ 22,193 $ — $ 22,193 Net premiums earned — — 21,816 — 21,816 Net investment income 3 10 2,315 — 2,328 Equity in earnings of subsidiaries 2,153 1,578 — (3,731 ) — Net realized gains (losses) including OTTI (2 ) (22 ) 108 — 84 Losses and loss expenses — — 14,182 — 14,182 Policy benefits — — 500 — 500 Policy acquisition costs and administrative expenses 56 28 6,346 — 6,430 Interest (income) expense (252 ) 641 62 — 451 Other (income) expense (7 ) 34 (360 ) — (333 ) Amortization of purchased intangibles — — 194 — 194 Chubb integration expenses 13 54 166 — 233 Income tax expense (benefit) 16 (288 ) 515 — 243 Net income $ 2,328 $ 1,097 $ 2,634 $ (3,731 ) $ 2,328 Comprehensive income $ 3,711 $ 2,459 $ 4,018 $ (6,477 ) $ 3,711 Condensed Consolidating Statements of Operations and Comprehensive Income For the Nine Months Ended September 30, 2016 Chubb Limited (Parent Guarantor) Chubb INA Holdings Inc. (Subsidiary Issuer) Other Chubb Limited Subsidiaries Consolidating Adjustments and Eliminations Chubb Limited Consolidated (in millions of U.S. dollars) Net premiums written $ — $ — $ 21,207 $ — $ 21,207 Net premiums earned — — 21,690 — 21,690 Net investment income 3 9 2,109 — 2,121 Equity in earnings of subsidiaries 2,331 1,803 — (4,134 ) — Net realized gains (losses) including OTTI (1 ) (3 ) (506 ) — (510 ) Losses and loss expenses — — 12,197 — 12,197 Policy benefits — — 427 — 427 Policy acquisition costs and administrative expenses 48 144 6,668 — 6,860 Interest (income) expense (266 ) 681 36 — 451 Other (income) expense (20 ) 26 (98 ) — (92 ) Amortization of purchased intangibles — — 16 — 16 Chubb integration expenses 29 56 276 — 361 Income tax expense (benefit) 17 (323 ) 862 — 556 Net income $ 2,525 $ 1,225 $ 2,909 $ (4,134 ) $ 2,525 Comprehensive income $ 4,457 $ 2,687 $ 4,841 $ (7,528 ) $ 4,457 Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2017 Chubb Limited (Parent Guarantor) Chubb INA Holdings Inc. (Subsidiary Issuer) Other Chubb Consolidating Adjustments and Eliminations Chubb Limited Consolidated (in millions of U.S. dollars) Net cash flows from operating activities $ 639 $ 1,472 $ 3,341 $ (2,041 ) $ 3,411 Cash flows from investing activities Purchases of fixed maturities available for sale — (9 ) (18,469 ) — (18,478 ) Purchases of fixed maturities held to maturity — — (262 ) — (262 ) Purchases of equity securities — — (125 ) — (125 ) Sales of fixed maturities available for sale — 99 9,116 — 9,215 Sales of equity securities — — 152 — 152 Maturities and redemptions of fixed maturities available for sale — 22 7,677 — 7,699 Maturities and redemptions of fixed maturities held to maturity — — 644 — 644 Net change in short-term investments — 197 (153 ) — 44 Net derivative instruments settlements — (13 ) (157 ) — (170 ) Other — 6 (68 ) — (62 ) Net cash flows from (used for) investing activities — 302 (1,645 ) — (1,343 ) Cash flows from financing activities Dividends paid on Common Shares (978 ) — — — (978 ) Common Shares repurchased — — (707 ) — (707 ) Repayment of long-term debt — (500 ) — — (500 ) Proceeds from issuance of repurchase agreements — — 1,798 — 1,798 Repayment of repurchase agreements — — (1,793 ) — (1,793 ) Proceeds from share-based compensation plans — — 109 — 109 Dividend to parent company — — (2,041 ) 2,041 — Advances (to) from affiliates 617 (658 ) 41 — — Net payments to affiliated notional cash pooling programs (1) (278 ) (617 ) — 895 — Policyholder contract deposits — — 312 — 312 Policyholder contract withdrawals — — (211 ) — (211 ) Net cash flows used for financing activities (639 ) (1,775 ) (2,492 ) 2,936 (1,970 ) Effect of foreign currency rate changes on cash and cash equivalents — — 5 — 5 Net increase (decrease) in cash — (1 ) (791 ) 895 103 Cash – beginning of period (1) 1 1 1,965 (982 ) 985 Cash – end of period (1) $ 1 $ — $ 1,174 $ (87 ) $ 1,088 (1) Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At September 30, 2017 and December 31, 2016, the cash balance of one or more entities was negative; however, the overall Pool balances were positive. Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2016 Chubb Limited (Parent Guarantor) Chubb INA Holdings Inc. (Subsidiary Issuer) Other Chubb Limited Subsidiaries Consolidating Adjustments and Eliminations Chubb Limited Consolidated (in millions of U.S. dollars) Net cash flows from operating activities $ 3,399 $ 3,892 $ 3,918 $ (7,372 ) $ 3,837 Cash flows from investing activities Purchases of fixed maturities available for sale — (154 ) (23,683 ) — (23,837 ) Purchases of fixed maturities held to maturity — — (189 ) — (189 ) Purchases of equity securities — — (100 ) — (100 ) Sales of fixed maturities available for sale — 66 13,797 — 13,863 Sales of equity securities — — 963 — 963 Maturities and redemptions of fixed maturities available for sale — 59 6,877 — 6,936 Maturities and redemptions of fixed maturities held to maturity — — 627 — 627 Net change in short-term investments — 7,627 4,239 — 11,866 Net derivative instruments settlements — (10 ) (171 ) — (181 ) Acquisition of subsidiaries (net of cash acquired of $71) — (14,282 ) 34 — (14,248 ) Capital contribution (2,330 ) (20 ) (2,330 ) 4,680 — Other — (3 ) 29 — 26 Net cash flows from (used for) investing activities (2,330 ) (6,717 ) 93 4,680 (4,274 ) Cash flows from financing activities Dividends paid on Common Shares (851 ) — — — (851 ) Proceeds from issuance of repurchase agreements — — 1,457 — 1,457 Repayment of repurchase agreements — — (1,455 ) — (1,455 ) Proceeds from share-based compensation plans, including windfall tax benefits — — 117 — 117 Dividend to parent company — — (7,372 ) 7,372 — Advances (to) from affiliates (258 ) 219 39 — — Capital contribution — 2,330 2,350 (4,680 ) — Net proceeds from (payments to) affiliated notional cash pooling programs (1) 45 280 — (325 ) — Policyholder contract deposits — — 473 — 473 Policyholder contract withdrawals — — (247 ) — (247 ) Other — (4 ) — — (4 ) Net cash flows from (used for) financing activities (1,064 ) 2,825 (4,638 ) 2,367 (510 ) Effect of foreign currency rate changes on cash and cash equivalents — — 42 — 42 Net increase (decrease) in cash 5 — (585 ) (325 ) (905 ) Cash – beginning of period (1) 1 2 2,743 (971 ) 1,775 Cash – end of period (1) $ 6 $ 2 $ 2,158 $ (1,296 ) $ 870 (1) Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At September 30, 2016 and December 31, 2015, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

General (Policies)

General (Policies)	9 Months Ended
	Sep. 30, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of presentation	General a) Basis of presentation Chubb Limited is a holding company incorporated in Zurich, Switzerland. Chubb Limited, through its subsidiaries, provides a broad range of insurance and reinsurance products to insureds worldwide. Chubb operates through the following business segments: North America Commercial P&C Insurance, North America Personal P&C Insurance, North America Agricultural Insurance, Overseas General Insurance, Global Reinsurance, and Life Insurance. Refer to Note 10 for additional information. The interim unaudited consolidated financial statements, which include the accounts of Chubb Limited and its subsidiaries (collectively, Chubb, we, us, or our), have been prepared in accordance with accounting principles generally accepted in the United States of America (GAAP) and, in the opinion of management, reflect all adjustments (consisting of normally recurring accruals) necessary for a fair statement of the results and financial position for such periods. All significant intercompany accounts and transactions, including internal reinsurance transactions, have been eliminated. The results of operations and cash flows for any interim period are not necessarily indicative of the results for the full year. These consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes included in our 2016 Form 10-K.
Accounting guidance adopted in 2017	d) Accounting guidance adopted in 2017 Stock Compensation Effective January 2017, we prospectively adopted new guidance on stock compensation which requires recognition of the excess tax benefits or deficiencies of share-based compensation awards to employees through net income rather than through additional paid in capital. The calculation of the excess tax benefits or deficiencies is based on the difference between the market value of a stock award at the date of vesting, or at the time of exercise for a stock option, compared to the grant date fair value recognized as compensation expense in the Consolidated statements of operations. For the three and nine months ended September 30, 2017, the excess tax benefit recorded to Income tax expense in the Consolidated statement of operations was $ 14 million and $44 million , respectively. Additionally, the guidance allowed for an election to account for forfeitures related to share-based payments either as they occur or through an estimation method. We elected to retain our current accounting for compensation expense using a forfeiture estimation process.
Accounting guidance not yet adopted	e) Accounting guidance not yet adopted Goodwill Impairment In January 2017, the FASB issued updated guidance on goodwill impairment testing that eliminates Step 2 of the goodwill impairment test requiring entities to calculate the implied fair value of goodwill through a hypothetical purchase price allocation. Under the updated guidance, impairment will now be recognized as the amount by which a reporting unit’s carrying value exceeds its fair value. The standard will be effective for us in the first quarter of 2020 on a prospective basis with early adoption permitted. We do not expect the adoption of this guidance to have a material effect on our financial condition and results of operations. Premium Amortization on Purchased Callable Debt Securities In March 2017, the FASB issued guidance on the amortization period for purchased callable debt securities held at a premium. The guidance requires the premium to be amortized to the earliest call date. Under current guidance, premiums generally are amortized over the contracted life of the security. This guidance is effective for us in the first quarter of 2019 on a modified retrospective basis through a cumulative effect adjustment to beginning retained earnings. Early adoption is permitted. Securities held at a discount do not require an accounting change. We are in the process of evaluating the effect the updated guidance will have on our financial condition and results of operations. Refer to the 2016 Form 10-K for information on other accounting guidance not yet adopted.

Acquisitions Acquisitions (Tabl

Acquisitions Acquisitions (Tables)	9 Months Ended
	Sep. 30, 2017
Acquisition [Abstract]
Results of Operations From Date of Business Combination [Table Text Block]	The following table summarizes the results of the acquired Chubb Corp operations within our 2016 Consolidated statements of operations for the periods presented: (in millions of U.S. dollars) Three Months Ended September 30, 2016 January 14, 2016 to September 30, 2016 Total revenues $ 2,656 $ 7,888 Net income $ 483 $ 1,064
Pro Forma Financial Information for the Chubb Corp Acquisition [Table Text Block]	The following table provides supplemental unaudited pro forma consolidated information for the three and nine months ended September 30, 2016 , as if Chubb Corp had been acquired as of January 1, 2015. The unaudited pro forma consolidated financial statements are presented solely for informational purposes and are not necessarily indicative of the consolidated results of operations that might have been achieved had the transaction been completed as of the date indicated, nor are they meant to be indicative of any anticipated consolidated future results of operations that the combined company will experience after the transaction. Three Months Ended Nine Months Ended (in millions of U.S. dollars, except per share data) September 30, 2016 September 30, 2016 Total revenues $ 8,521 $ 23,758 Net income $ 1,345 $ 2,591 Earnings per share Basic earnings per share $ 2.87 $ 5.54 Diluted earnings per share $ 2.85 $ 5.50

Investments (Tables)

Investments (Tables)	9 Months Ended
	Sep. 30, 2017
Investments, Debt and Equity Securities [Abstract]
Schedule Of Amortized Cost And Fair Value Of HTM Fixed Maturities And Related OTTI Recognized In AOCI	September 30, 2017 Amortized Cost Gross Unrealized Appreciation Gross Unrealized Depreciation Fair Value OTTI Recognized in AOCI (in millions of U.S. dollars) Available for sale U.S. Treasury and agency $ 3,571 $ 38 $ (27 ) $ 3,582 $ — Foreign 22,516 690 (107 ) 23,099 (2 ) Corporate securities 24,555 754 (83 ) 25,226 (4 ) Mortgage-backed securities 15,369 157 (115 ) 15,411 (1 ) States, municipalities, and political subdivisions 16,243 172 (47 ) 16,368 — $ 82,254 $ 1,811 $ (379 ) $ 83,686 $ (7 ) Held to maturity U.S. Treasury and agency $ 611 $ 13 $ (3 ) $ 621 $ — Foreign 616 28 — 644 — Corporate securities 2,531 63 (5 ) 2,589 — Mortgage-backed securities 1,223 35 — 1,258 — States, municipalities, and political subdivisions 5,179 77 (3 ) 5,253 — $ 10,160 $ 216 $ (11 ) $ 10,365 $ — December 31, 2016 Amortized Cost Gross Unrealized Appreciation Gross Unrealized Depreciation Fair Value OTTI Recognized in AOCI (in millions of U.S. dollars) Available for sale U.S. Treasury and agency $ 2,883 $ 32 $ (45 ) $ 2,870 $ — Foreign 20,929 636 (125 ) 21,440 (5 ) Corporate securities 23,736 580 (167 ) 24,149 (8 ) Mortgage-backed securities 14,066 135 (194 ) 14,007 (1 ) States, municipalities, and political subdivisions 17,922 72 (345 ) 17,649 — $ 79,536 $ 1,455 $ (876 ) $ 80,115 $ (14 ) Held to maturity U.S. Treasury and agency $ 655 $ 9 $ (3 ) $ 661 $ — Foreign 640 28 (1 ) 667 — Corporate securities 2,771 50 (26 ) 2,795 — Mortgage-backed securities 1,393 35 — 1,428 — States, municipalities, and political subdivisions 5,185 26 (92 ) 5,119 — $ 10,644 $ 148 $ (122 ) $ 10,670 $ —
Schedule Of Fixed Maturities By Contractual Maturity	The following table presents fixed maturities by contractual maturity: September 30 December 31 2017 2016 (in millions of U.S. dollars) Amortized Cost Fair Value Amortized Cost Fair Value Available for sale Due in 1 year or less $ 3,532 $ 3,556 $ 3,892 $ 3,913 Due after 1 year through 5 years 24,918 25,397 24,027 24,429 Due after 5 years through 10 years 28,009 28,488 27,262 27,379 Due after 10 years 10,426 10,834 10,289 10,387 66,885 68,275 65,470 66,108 Mortgage-backed securities 15,369 15,411 14,066 14,007 $ 82,254 $ 83,686 $ 79,536 $ 80,115 Held to maturity Due in 1 year or less $ 822 $ 828 $ 430 $ 435 Due after 1 year through 5 years 2,479 2,524 2,646 2,691 Due after 5 years through 10 years 2,821 2,866 2,969 2,944 Due after 10 years 2,815 2,889 3,206 3,172 8,937 9,107 9,251 9,242 Mortgage-backed securities 1,223 1,258 1,393 1,428 $ 10,160 $ 10,365 $ 10,644 $ 10,670
Schedule Of Amortized Cost and Fair Value of Available-for-sale Securities and Related OTTI Recognized in AOCI	September 30, 2017 Amortized Cost Gross Unrealized Appreciation Gross Unrealized Depreciation Fair Value OTTI Recognized in AOCI (in millions of U.S. dollars) Available for sale U.S. Treasury and agency $ 3,571 $ 38 $ (27 ) $ 3,582 $ — Foreign 22,516 690 (107 ) 23,099 (2 ) Corporate securities 24,555 754 (83 ) 25,226 (4 ) Mortgage-backed securities 15,369 157 (115 ) 15,411 (1 ) States, municipalities, and political subdivisions 16,243 172 (47 ) 16,368 — $ 82,254 $ 1,811 $ (379 ) $ 83,686 $ (7 ) Held to maturity U.S. Treasury and agency $ 611 $ 13 $ (3 ) $ 621 $ — Foreign 616 28 — 644 — Corporate securities 2,531 63 (5 ) 2,589 — Mortgage-backed securities 1,223 35 — 1,258 — States, municipalities, and political subdivisions 5,179 77 (3 ) 5,253 — $ 10,160 $ 216 $ (11 ) $ 10,365 $ — December 31, 2016 Amortized Cost Gross Unrealized Appreciation Gross Unrealized Depreciation Fair Value OTTI Recognized in AOCI (in millions of U.S. dollars) Available for sale U.S. Treasury and agency $ 2,883 $ 32 $ (45 ) $ 2,870 $ — Foreign 20,929 636 (125 ) 21,440 (5 ) Corporate securities 23,736 580 (167 ) 24,149 (8 ) Mortgage-backed securities 14,066 135 (194 ) 14,007 (1 ) States, municipalities, and political subdivisions 17,922 72 (345 ) 17,649 — $ 79,536 $ 1,455 $ (876 ) $ 80,115 $ (14 ) Held to maturity U.S. Treasury and agency $ 655 $ 9 $ (3 ) $ 661 $ — Foreign 640 28 (1 ) 667 — Corporate securities 2,771 50 (26 ) 2,795 — Mortgage-backed securities 1,393 35 — 1,428 — States, municipalities, and political subdivisions 5,185 26 (92 ) 5,119 — $ 10,644 $ 148 $ (122 ) $ 10,670 $ — September 30 December 31 (in millions of U.S. dollars) 2017 2016 Cost $ 723 $ 706 Gross unrealized appreciation 195 129 Gross unrealized depreciation (8 ) (21 ) Fair value $ 910 $ 814
Schedule of Realized Gain (Loss)	The following table presents the Net realized gains (losses) and the losses included in Net realized gains (losses) and OCI as a result of conditions which caused us to conclude the decline in fair value of certain investments was “other-than-temporary”: Three Months Ended Nine Months Ended September 30 September 30 (in millions of U.S. dollars) 2017 2016 2017 2016 Fixed maturities: OTTI on fixed maturities, gross $ (5 ) $ (7 ) $ (16 ) $ (85 ) OTTI on fixed maturities recognized in OCI (pre-tax) — — 1 8 OTTI on fixed maturities, net (5 ) (7 ) (15 ) (77 ) Gross realized gains excluding OTTI 30 47 109 149 Gross realized losses excluding OTTI (19 ) (13 ) (77 ) (228 ) Total fixed maturities 6 27 17 (156 ) Equity securities: OTTI on equity securities (1 ) (1 ) (9 ) (7 ) Gross realized gains excluding OTTI 6 19 21 63 Gross realized losses excluding OTTI (1 ) (12 ) (2 ) (17 ) Total equity securities 4 6 10 39 OTTI on other investments (2 ) (4 ) (11 ) (7 ) Foreign exchange gains 15 29 10 46 Investment and embedded derivative instruments (14 ) 1 (24 ) (85 ) Fair value adjustments on insurance derivative 54 89 265 (270 ) S&P put options and futures (57 ) (45 ) (169 ) (88 ) Other derivative instruments (5 ) 3 (4 ) 1 Other (11 ) (6 ) (10 ) 10 Net realized gains (losses) $ (10 ) $ 100 $ 84 $ (510 )
Schedule Of Roll-Forward Of Pre-Tax Credit Losses Related To Fixed Maturities For Which A Portion Of OTTI Was Recognized In OCI	The following table presents a roll-forward of pre-tax credit losses related to fixed maturities for which a portion of OTTI was recognized in OCI: Three Months Ended Nine Months Ended September 30 September 30 (in millions of U.S. dollars) 2017 2016 2017 2016 Balance of credit losses related to securities still held – beginning of period $ 29 $ 51 $ 35 $ 53 Additions where no OTTI was previously recorded 2 4 3 16 Additions where an OTTI was previously recorded 1 1 2 13 Reductions for securities sold during the period (7 ) (11 ) (15 ) (37 ) Balance of credit losses related to securities still held – end of period $ 25 $ 45 $ 25 $ 45
Schedule Of Aggregate Fair Value And Gross Unrealized Loss By Length Of Time The Security Has Continuously Been In An Unrealized Loss Position	The following tables present, for all securities in an unrealized loss position (including securities on loan), the aggregate fair value and gross unrealized loss by length of time the security has continuously been in an unrealized loss position: 0 – 12 Months Over 12 Months Total September 30, 2017 Fair Value Gross Unrealized Loss Fair Value Gross Unrealized Loss Fair Value Gross Unrealized Loss (in millions of U.S. dollars) U.S. Treasury and agency $ 1,763 $ (13 ) $ 656 $ (17 ) $ 2,419 $ (30 ) Foreign 5,353 (85 ) 894 (22 ) 6,247 (107 ) Corporate securities 3,373 (48 ) 788 (40 ) 4,161 (88 ) Mortgage-backed securities 6,946 (96 ) 749 (19 ) 7,695 (115 ) States, municipalities, and political subdivisions 4,548 (28 ) 839 (22 ) 5,387 (50 ) Total fixed maturities 21,983 (270 ) 3,926 (120 ) 25,909 (390 ) Equity securities 103 (8 ) — — 103 (8 ) Other investments 157 (9 ) — — 157 (9 ) Total $ 22,243 $ (287 ) $ 3,926 $ (120 ) $ 26,169 $ (407 ) 0 – 12 Months Over 12 Months Total December 31, 2016 Fair Value Gross Unrealized Loss Fair Value Gross Unrealized Loss Fair Value Gross Unrealized Loss (in millions of U.S. dollars) U.S. Treasury and agency $ 2,216 $ (48 ) $ — $ — $ 2,216 $ (48 ) Foreign 5,918 (99 ) 386 (27 ) 6,304 (126 ) Corporate securities 7,021 (149 ) 641 (44 ) 7,662 (193 ) Mortgage-backed securities 8,638 (189 ) 234 (5 ) 8,872 (194 ) States, municipalities, and political subdivisions 19,448 (435 ) 49 (2 ) 19,497 (437 ) Total fixed maturities 43,241 (920 ) 1,310 (78 ) 44,551 (998 ) Equity securities 199 (21 ) — — 199 (21 ) Other investments 201 (18 ) — — 201 (18 ) Total $ 43,641 $ (959 ) $ 1,310 $ (78 ) $ 44,951 $ (1,037 )
Schedule Of Components Of Restricted Assets	The following table presents the components of restricted assets: September 30 December 31 (in millions of U.S. dollars) 2017 2016 Trust funds $ 16,391 $ 13,880 Deposits with U.S. regulatory authorities 2,361 2,203 Deposits with non-U.S. regulatory authorities 2,294 2,191 Assets pledged under repurchase agreements 1,441 1,461 Other pledged assets 377 435 $ 22,864 $ 20,170

Fair value measurements (Tables

Fair value measurements (Tables)	9 Months Ended
	Sep. 30, 2017
Fair Value Disclosures [Abstract]
Financial Instruments Measured At Fair Value On A Recurring Basis	Financial instruments measured at fair value on a recurring basis, by valuation hierarchy September 30, 2017 Level 1 Level 2 Level 3 Total (in millions of U.S. dollars) Assets: Fixed maturities available for sale U.S. Treasury and agency $ 2,941 $ 641 $ — $ 3,582 Foreign — 23,009 90 23,099 Corporate securities — 24,307 919 25,226 Mortgage-backed securities — 15,367 44 15,411 States, municipalities, and political subdivisions — 16,368 — 16,368 2,941 79,692 1,053 83,686 Equity securities 858 — 52 910 Short-term investments 1,804 1,187 — 2,991 Other investments (1) 446 292 252 990 Securities lending collateral — 1,757 — 1,757 Investment derivative instruments 15 — — 15 Separate account assets 2,414 100 — 2,514 Total assets measured at fair value (1) $ 8,478 $ 83,028 $ 1,357 $ 92,863 Liabilities: Investment derivative instruments $ 37 $ — $ — $ 37 Other derivative instruments 25 — 2 27 GLB (2) — — 303 303 Total liabilities measured at fair value $ 62 $ — $ 305 $ 367 (1) Excluded from the table above are partially-owned investments, investment funds, and limited partnerships of $ 3,669 million and other investments of $ 18 million at September 30, 2017 measured using NAV as a practical expedient. (2) Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. December 31, 2016 Level 1 Level 2 Level 3 Total (in millions of U.S. dollars) Assets: Fixed maturities available for sale U.S. Treasury and agency $ 2,175 $ 695 $ — $ 2,870 Foreign — 21,366 74 21,440 Corporate securities — 23,468 681 24,149 Mortgage-backed securities — 13,962 45 14,007 States, municipalities, and political subdivisions — 17,649 — 17,649 2,175 77,140 800 80,115 Equity securities 773 — 41 814 Short-term investments 1,757 1,220 25 3,002 Other investments (1) 384 259 225 868 Securities lending collateral — 1,092 — 1,092 Investment derivative instruments 31 — — 31 Other derivative instruments 3 — — 3 Separate account assets 1,784 95 — 1,879 Total assets measured at fair value (1) $ 6,907 $ 79,806 $ 1,091 $ 87,804 Liabilities: Investment derivative instruments $ 54 $ — $ — $ 54 Other derivative instruments — — 13 13 GLB (2) — — 559 559 Total liabilities measured at fair value $ 54 $ — $ 572 $ 626 (1) Excluded from the table above are partially-owned investments, investment funds, and limited partnerships of $3,626 million and other investments of $25 million at December 31, 2016 measured using NAV as a practical expedient. (2) Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets.
Fair Value And Maximum Future Funding Commitments Related To Investments	The following table presents, by investment category, the expected liquidation period, fair value, and maximum future funding commitments of alternative investments: September 30 December 31 Expected Liquidation Period of Underlying Assets 2017 2016 (in millions of U.S. dollars) Fair Value Maximum Future Funding Commitments Fair Value Maximum Future Funding Commitments Financial 5 to 9 Years $ 566 $ 367 $ 548 $ 428 Real Assets 3 to 7 Years 635 148 536 230 Distressed 5 to 9 Years 327 157 485 179 Private Credit 3 to 7 Years 216 329 236 259 Traditional 3 to 9 Years 1,643 729 1,550 930 Vintage 1 to 2 Years 18 — 21 14 Investment funds Not Applicable 264 — 251 — $ 3,669 $ 1,730 $ 3,627 $ 2,040
Schedule Of Significant Unobservable Inputs Used In Level 3 Liability Valuations	The following table presents the significant unobservable inputs used in the Level 3 liability valuations. Excluded from the table below are inputs used to determine the fair value of Level 3 assets which are based on single broker quotes and contain no quantitative unobservable inputs developed by management. (in millions of U.S. dollars, except for percentages) Fair Value Valuation Technique Significant Unobservable Inputs Ranges September 30, 2017 December 31, 2016 GLB (1) $ 303 $ 559 Actuarial model Lapse rate 3% – 34% Annuitization rate 0% – 78% (1) Discussion of the most significant inputs used in the fair value measurement of GLB and the sensitivity of those assumptions is included within Note 4 a) Guaranteed living benefits.
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	The following tables present a reconciliation of the beginning and ending balances of financial instruments measured at fair value using significant unobservable inputs (Level 3): Assets Liabilities Three Months Ended Available-for-Sale Debt Securities Equity securities Short-term investments Other investments Other derivative instruments GLB (1) September 30, 2017 Foreign Corporate securities MBS (in millions of U.S. dollars) Balance – beginning of period $ 85 $ 747 $ 45 $ 39 $ 7 $ 243 $ 2 $ 357 Transfers into Level 3 — 111 — — — — — — Transfers out of Level 3 (3 ) (26 ) — — — — — — Change in Net Unrealized Gains (Losses) included in OCI 1 (1 ) — — — — — — Net Realized Gains/Losses — — — 1 — — — (54 ) Purchases 24 169 7 17 1 15 — — Sales (14 ) (24 ) — (5 ) — — — — Settlements (3 ) (57 ) (8 ) — (8 ) (6 ) — — Balance – end of period $ 90 $ 919 $ 44 $ 52 $ — $ 252 $ 2 $ 303 Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date $ — $ — $ — $ — $ — $ — $ — $ (54 ) (1) Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $635 million at September 30, 2017, and $684 million at June 30, 2017, which includes a fair value derivative adjustment of $303 million and $357 million , respectively. Assets Liabilities Three Months Ended Available-for-Sale Debt Securities Equity Short-term investments Other Other derivative instruments GLB (1) September 30, 2016 Foreign Corporate MBS (in millions of U.S. dollars) Balance – beginning of period $ 87 $ 281 $ 49 $ 37 $ 50 $ 216 $ 10 $ 971 Transfers into Level 3 — — — — — — — — Transfers out of Level 3 — — — — — — — — Change in Net Unrealized Gains (Losses) included in OCI (1 ) 6 — 3 — 4 — — Net Realized Gains/Losses — (4 ) — — — — — (88 ) Purchases 20 348 — — 12 8 — — Sales (2 ) (18 ) (3 ) (3 ) — — — — Settlements (1 ) (7 ) — — — (5 ) (2 ) — Balance – end of period $ 103 $ 606 $ 46 $ 37 $ 62 $ 223 $ 8 $ 883 Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date $ — $ (4 ) $ — $ — $ — $ — $ — $ (88 ) (1) Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $1.2 billion at September 30, 2016 , and $1.3 billion at June 30, 2016, which includes a fair value derivative adjustment of $883 million and $971 million, respectively. Assets Liabilities Nine Months Ended Available-for-Sale Debt Securities Equity securities Short-term investments Other investments Other derivative instruments GLB (1) September 30, 2017 Foreign Corporate securities MBS (in millions of U.S. dollars) Balance – beginning of period $ 74 $ 681 $ 45 $ 41 $ 25 $ 225 $ 13 $ 559 Transfers into Level 3 — 168 — — — — — 9 Transfers out of Level 3 (3 ) (93 ) — — — — (9 ) — Change in Net Unrealized Gains (Losses) included in OCI 3 (9 ) — 1 — 3 — — Net Realized Gains/Losses 1 (1 ) — 1 — — (2 ) (265 ) Purchases 57 390 8 23 15 39 — — Sales (36 ) (79 ) (1 ) (14 ) — — — — Settlements (6 ) (138 ) (8 ) — (40 ) (15 ) — — Balance – end of period $ 90 $ 919 $ 44 $ 52 $ — $ 252 $ 2 $ 303 Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date $ — $ — $ — $ — $ — $ — $ (2 ) $ (265 ) (1) Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $635 million at September 30, 2017, and $853 million at December 31, 2016, which includes a fair value derivative adjustment of $303 million and $559 million , respectively. Assets Liabilities Nine Months Ended Available-for-Sale Debt Securities Equity Short-term investments Other Other derivative instruments GLB (1) September 30, 2016 Foreign Corporate MBS (in millions of U.S. dollars) Balance – beginning of period $ 57 $ 174 $ 53 $ 16 $ — $ 212 $ 6 $ 609 Transfers into Level 3 9 18 — — — — — — Transfers out of Level 3 (2 ) — — — — — — — Change in Net Unrealized Gains (Losses) included in OCI 8 17 — 2 — 4 — — Net Realized Gains/Losses (6 ) (12 ) — 1 — — 2 274 Purchases (2) 52 472 1 23 62 22 2 — Sales (10 ) (48 ) (8 ) (5 ) — — — — Settlements (5 ) (15 ) — — — (15 ) (2 ) — Balance – end of period $ 103 $ 606 $ 46 $ 37 $ 62 $ 223 $ 8 $ 883 Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date $ (5 ) $ (11 ) $ — $ — $ — $ — $ 2 $ 274 (1) Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $1.2 billion at September 30, 2016 , and $888 million at December 31, 2015, which includes a fair value derivative adjustment of $883 million and $609 million , respectively. (2) Includes acquired invested assets as a result of the Chubb Corp acquisition.
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Table Text Block]	The following tables present a reconciliation of the beginning and ending balances of financial instruments measured at fair value using significant unobservable inputs (Level 3): Assets Liabilities Three Months Ended Available-for-Sale Debt Securities Equity securities Short-term investments Other investments Other derivative instruments GLB (1) September 30, 2017 Foreign Corporate securities MBS (in millions of U.S. dollars) Balance – beginning of period $ 85 $ 747 $ 45 $ 39 $ 7 $ 243 $ 2 $ 357 Transfers into Level 3 — 111 — — — — — — Transfers out of Level 3 (3 ) (26 ) — — — — — — Change in Net Unrealized Gains (Losses) included in OCI 1 (1 ) — — — — — — Net Realized Gains/Losses — — — 1 — — — (54 ) Purchases 24 169 7 17 1 15 — — Sales (14 ) (24 ) — (5 ) — — — — Settlements (3 ) (57 ) (8 ) — (8 ) (6 ) — — Balance – end of period $ 90 $ 919 $ 44 $ 52 $ — $ 252 $ 2 $ 303 Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date $ — $ — $ — $ — $ — $ — $ — $ (54 ) (1) Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $635 million at September 30, 2017, and $684 million at June 30, 2017, which includes a fair value derivative adjustment of $303 million and $357 million , respectively. Assets Liabilities Three Months Ended Available-for-Sale Debt Securities Equity Short-term investments Other Other derivative instruments GLB (1) September 30, 2016 Foreign Corporate MBS (in millions of U.S. dollars) Balance – beginning of period $ 87 $ 281 $ 49 $ 37 $ 50 $ 216 $ 10 $ 971 Transfers into Level 3 — — — — — — — — Transfers out of Level 3 — — — — — — — — Change in Net Unrealized Gains (Losses) included in OCI (1 ) 6 — 3 — 4 — — Net Realized Gains/Losses — (4 ) — — — — — (88 ) Purchases 20 348 — — 12 8 — — Sales (2 ) (18 ) (3 ) (3 ) — — — — Settlements (1 ) (7 ) — — — (5 ) (2 ) — Balance – end of period $ 103 $ 606 $ 46 $ 37 $ 62 $ 223 $ 8 $ 883 Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date $ — $ (4 ) $ — $ — $ — $ — $ — $ (88 ) (1) Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $1.2 billion at September 30, 2016 , and $1.3 billion at June 30, 2016, which includes a fair value derivative adjustment of $883 million and $971 million, respectively. Assets Liabilities Nine Months Ended Available-for-Sale Debt Securities Equity securities Short-term investments Other investments Other derivative instruments GLB (1) September 30, 2017 Foreign Corporate securities MBS (in millions of U.S. dollars) Balance – beginning of period $ 74 $ 681 $ 45 $ 41 $ 25 $ 225 $ 13 $ 559 Transfers into Level 3 — 168 — — — — — 9 Transfers out of Level 3 (3 ) (93 ) — — — — (9 ) — Change in Net Unrealized Gains (Losses) included in OCI 3 (9 ) — 1 — 3 — — Net Realized Gains/Losses 1 (1 ) — 1 — — (2 ) (265 ) Purchases 57 390 8 23 15 39 — — Sales (36 ) (79 ) (1 ) (14 ) — — — — Settlements (6 ) (138 ) (8 ) — (40 ) (15 ) — — Balance – end of period $ 90 $ 919 $ 44 $ 52 $ — $ 252 $ 2 $ 303 Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date $ — $ — $ — $ — $ — $ — $ (2 ) $ (265 ) (1) Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $635 million at September 30, 2017, and $853 million at December 31, 2016, which includes a fair value derivative adjustment of $303 million and $559 million , respectively. Assets Liabilities Nine Months Ended Available-for-Sale Debt Securities Equity Short-term investments Other Other derivative instruments GLB (1) September 30, 2016 Foreign Corporate MBS (in millions of U.S. dollars) Balance – beginning of period $ 57 $ 174 $ 53 $ 16 $ — $ 212 $ 6 $ 609 Transfers into Level 3 9 18 — — — — — — Transfers out of Level 3 (2 ) — — — — — — — Change in Net Unrealized Gains (Losses) included in OCI 8 17 — 2 — 4 — — Net Realized Gains/Losses (6 ) (12 ) — 1 — — 2 274 Purchases (2) 52 472 1 23 62 22 2 — Sales (10 ) (48 ) (8 ) (5 ) — — — — Settlements (5 ) (15 ) — — — (15 ) (2 ) — Balance – end of period $ 103 $ 606 $ 46 $ 37 $ 62 $ 223 $ 8 $ 883 Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date $ (5 ) $ (11 ) $ — $ — $ — $ — $ 2 $ 274 (1) Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $1.2 billion at September 30, 2016 , and $888 million at December 31, 2015, which includes a fair value derivative adjustment of $883 million and $609 million , respectively. (2) Includes acquired invested assets as a result of the Chubb Corp acquisition.
Carrying Values And Fair Values Of Financial Instruments Not Measured At Fair Value	The following tables present fair value, by valuation hierarchy, and carrying value of the financial instruments not measured at fair value: September 30, 2017 Fair Value Carrying Value (in millions of U.S. dollars) Level 1 Level 2 Level 3 Total Assets: Fixed maturities held to maturity U.S. Treasury and agency $ 563 $ 58 $ — $ 621 $ 611 Foreign — 644 — 644 616 Corporate securities — 2,578 11 2,589 2,531 Mortgage-backed securities — 1,258 — 1,258 1,223 States, municipalities, and political subdivisions — 5,253 — 5,253 5,179 Total assets $ 563 $ 9,791 $ 11 $ 10,365 $ 10,160 Liabilities: Repurchase agreements $ — $ 1,408 $ — $ 1,408 $ 1,408 Short-term debt — 1,025 — 1,025 1,020 Long-term debt — 12,273 — 12,273 11,559 Trust preferred securities — 467 — 467 308 Total liabilities $ — $ 15,173 $ — $ 15,173 $ 14,295 December 31, 2016 Fair Value Carrying Value (in millions of U.S. dollars) Level 1 Level 2 Level 3 Total Assets: Fixed maturities held to maturity U.S. Treasury and agency $ 555 $ 106 $ — $ 661 $ 655 Foreign — 667 — 667 640 Corporate securities — 2,782 13 2,795 2,771 Mortgage-backed securities — 1,428 — 1,428 1,393 States, municipalities, and political subdivisions — 5,119 — 5,119 5,185 Total assets $ 555 $ 10,102 $ 13 $ 10,670 $ 10,644 Liabilities: Repurchase agreements $ — $ 1,403 $ — $ 1,403 $ 1,403 Short-term debt — 503 — 503 500 Long-term debt — 12,998 — 12,998 12,610 Trust preferred securities — 456 — 456 308 Total liabilities $ — $ 15,360 $ — $ 15,360 $ 14,821

Unpaid losses and loss expens26

Unpaid losses and loss expenses Unpaid losses and loss expenses (Tables)	9 Months Ended
	Sep. 30, 2017
Liability for Claims and Claims Adjustment Expense [Abstract]
Schedule of Liability for Unpaid Claims and Claims Adjustment Expense [Table Text Block]	The following table presents a reconciliation of beginning and ending Unpaid losses and loss expenses: Nine Months Ended September 30 (in millions of U.S. dollars) 2017 2016 Gross unpaid losses and loss expenses – beginning of period $ 60,540 $ 37,303 Reinsurance recoverable on unpaid losses (1) (12,708 ) (10,741 ) Net unpaid losses and loss expenses – beginning of period 47,832 26,562 Acquisition of subsidiaries — 21,402 Total 47,832 47,964 Net losses and loss expenses incurred in respect of losses occurring in: Current year 14,963 13,169 Prior years (2) (781 ) (972 ) Total 14,182 12,197 Net losses and loss expenses paid in respect of losses occurring in: Current year 3,937 3,865 Prior years 8,389 7,470 Total 12,326 11,335 Foreign currency revaluation and other 596 (155 ) Net unpaid losses and loss expenses – end of period 50,283 48,671 Reinsurance recoverable on unpaid losses (1) 13,870 12,676 Gross unpaid losses and loss expenses – end of period $ 64,153 $ 61,347 (1) Net of provision for uncollectible reinsurance. (2) Relates to prior period loss reserve development only and excludes prior period development related to reinstatement premiums, expense adjustments, and earned premiums totaling $110 million and $75 million for the nine months ended September 30, 2017 and 2016, respectively.

Commitments, contingencies, a27

Commitments, contingencies, and guarantees (Tables)	9 Months Ended
	Sep. 30, 2017
Commitments and Contingencies Disclosure [Abstract]
Balance Sheet Locations, Fair Values In An Asset Or (Liability) Position, And Notional Values/Payment Provisions Of Derivative Instruments	The following table presents the balance sheet locations, fair values of derivative instruments in an asset or (liability) position, and notional values/payment provisions of our derivative instruments: September 30, 2017 December 31, 2016 Consolidated Balance Sheet Location Fair Value Notional Value/ Payment Provision Fair Value Notional Value/ Payment Provision (in millions of U.S. dollars) Derivative Asset Derivative (Liability) Derivative Asset Derivative (Liability) Investment and embedded derivative instruments: Foreign currency forward contracts OA / (AP) $ 8 $ (31 ) $ 2,035 $ 25 $ (50 ) $ 2,220 Cross-currency swaps OA / (AP) — — 45 — — 95 Options/Futures contracts on notes and bonds OA / (AP) 7 (6 ) 1,437 6 (4 ) 2,344 Convertible securities (1) FM AFS / ES — — 4 2 — 7 $ 15 $ (37 ) $ 3,521 $ 33 $ (54 ) $ 4,666 Other derivative instruments: Futures contracts on equities (2) OA / (AP) $ — $ (25 ) $ 1,455 $ 1 $ — $ 1,316 Other OA / (AP) — (2 ) 259 2 (13 ) 214 $ — $ (27 ) $ 1,714 $ 3 $ (13 ) $ 1,530 GLB (3) (AP) / (FPB) $ — $ (635 ) $ 1,138 $ — $ (853 ) $ 1,264 (1) Includes fair value of embedded derivatives. (2) Related to GMDB and GLB blocks of business. (3) Includes both future policy benefits reserves and fair value derivative adjustment. Note that the payment provision related to GLB is the net amount at risk. The concept of a notional value does not apply to the GLB reinsurance contracts.
Transfer of Certain Financial Assets Accounted for as Secured Borrowings	The following table presents the carrying value of collateral held under securities lending agreements by investment category and remaining contractual maturity of the underlying agreements: Remaining contractual maturity September 30 December 31 2017 2016 (in millions of U.S. dollars) Overnight and Continuous Collateral held under securities lending agreements: Cash $ 1,109 $ 423 U.S. Treasury and agency 38 54 Foreign 491 578 Corporate securities — 37 Mortgage-backed securities 46 — Equity securities 73 — $ 1,757 $ 1,092 Gross amount of recognized liability for securities lending payable $ 1,757 $ 1,093 Difference (1) $ — $ (1 ) (1) The carrying value of the securities lending collateral held is $ 1 million lower than the securities lending payable at December 31, 2016 due to accrued interest recorded in the securities lending payable.
Secured Borrowings Securities Lending Table Text Block [Table Text Block]	The following table presents the carrying value of collateral pledged under repurchase agreements by investment category and remaining contractual maturity of the underlying agreements: Remaining contractual maturity September 30, 2017 December 31, 2016 Up to 30 Days Greater than 90 Days Total Up to 30 Days Greater than 90 Days Total (in millions of U.S. dollars) Collateral pledged under repurchase agreements: Cash $ — $ — $ — $ — $ 1 $ 1 U.S. Treasury and agency 231 9 240 230 10 240 Mortgage-backed securities 343 858 1,201 339 881 1,220 $ 574 $ 867 $ 1,441 $ 569 $ 892 $ 1,461 Gross amount of recognized liabilities for repurchase agreements $ 1,408 $ 1,403 Difference (1) $ 33 $ 58
Net Realized Gains (Losses) Of Derivative Instrument Activity In Consolidated Statement Of Operations	The following table presents net realized gains (losses) related to derivative instrument activity in the Consolidated statements of operations: Three Months Ended Nine Months Ended September 30 September 30 (in millions of U.S. dollars) 2017 2016 2017 2016 Investment and embedded derivative instruments: Foreign currency forward contracts $ (7 ) $ (10 ) $ — $ (30 ) All other futures contracts and options (8 ) 8 (25 ) (63 ) Convertible securities (1) 1 3 1 8 Total investment and embedded derivative instruments $ (14 ) $ 1 $ (24 ) $ (85 ) GLB and other derivative instruments: GLB (2) $ 54 $ 89 $ 265 $ (270 ) Futures contracts on equities (3) (57 ) (45 ) (169 ) (88 ) Other (5 ) 3 (4 ) 1 Total GLB and other derivative instruments $ (8 ) $ 47 $ 92 $ (357 ) $ (22 ) $ 48 $ 68 $ (442 ) (1) Includes embedded derivatives. (2) Excludes foreign exchange gains (losses) related to GLB. (3) Related to GMDB and GLB blocks of business.

Shareholders' equity Shareholde

Shareholders' equity Shareholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2017
Stockholders' Equity Note [Abstract]
Dividends Declared [Table Text Block]	The following table presents dividend distributions per Common Share in Swiss francs (CHF) and U.S. dollars (USD): Three Months Ended Nine Months Ended September 30 September 30 2017 2016 2017 2016 CHF USD CHF USD CHF USD CHF USD Total dividend distributions per common share 0.68 $ 0.71 0.67 $ 0.69 2.06 $ 2.11 2.01 $ 2.05
Share Repurchase Program [Table Text Block]	Repurchases of Chubb's Common Shares conducted in a series of open market transactions from January 1, 2017 through October 31, 2017 under the Board authorization are as follows: (in millions of U.S. dollars, except share data) Three Months Ended September 30, 2017 Nine Months Ended September 30, 2017 October 1, 2017 through October 31, 2017 Number of shares repurchased 1,615,383 5,033,013 25,000 Cost of shares repurchased $ 232 $ 707 $ 4 Repurchase authorization remaining at end of period $ 293 $ 293 $ 289

Postretirement benefits (Tables

Postretirement benefits (Tables)	9 Months Ended
	Sep. 30, 2017
Retirement Benefits [Abstract]
Schedule of Net Benefit Costs [Table Text Block]	The components of net pension and other postretirement benefit costs (benefits) reflected in Net income in the Consolidated statements of operations were as follows: Three Months Ended September 30 Pension Benefits Other Postretirement Benefits U.S. Plans Non-U.S. Plans Total U.S. Plans Non-U.S. Plans Total (in millions of U.S. dollars) 2017 Service cost $ 15 $ 6 $ 21 $ — $ — $ — Interest cost 27 6 33 1 1 2 Expected return on plan assets (47 ) (11 ) (58 ) (2 ) — (2 ) Amortization of net actuarial loss — 1 1 — — — Amortization of prior service cost — — — (22 ) — (22 ) Curtailments — — — (32 ) — (32 ) Net periodic (benefit) cost $ (5 ) $ 2 $ (3 ) $ (55 ) $ 1 $ (54 ) 2016 Service cost $ 20 $ 6 $ 26 $ 4 $ — $ 4 Interest cost 26 8 34 4 — 4 Expected return on plan assets (42 ) (10 ) (52 ) (3 ) — (3 ) Amortization of net actuarial loss — — — — — — Curtailments (4 ) — (4 ) — — — Settlements (1 ) — (1 ) — — — Net periodic (benefit) cost $ (1 ) $ 4 $ 3 $ 5 $ — $ 5 Nine Months Ended September 30 Pension Benefits Other Postretirement Benefits U.S. Plans Non-U.S. Plans Total U.S. Plans Non-U.S. Plans Total (in millions of U.S. dollars) 2017 Service cost $ 47 $ 14 $ 61 $ 1 $ 1 $ 2 Interest cost 79 20 99 2 1 3 Expected return on plan assets (142 ) (31 ) (173 ) (4 ) — (4 ) Amortization of net actuarial loss — 2 2 — — — Amortization of prior service cost — — — (68 ) — (68 ) Curtailments — (8 ) (8 ) (32 ) — (32 ) Net periodic (benefit) cost $ (16 ) $ (3 ) $ (19 ) $ (101 ) $ 2 $ (99 ) 2016 Service cost $ 57 $ 15 $ 72 $ 8 $ 1 $ 9 Interest cost 80 24 104 13 — 13 Expected return on plan assets (121 ) (30 ) (151 ) (7 ) — (7 ) Amortization of net actuarial loss — 2 2 — — — Curtailments (4 ) — (4 ) — — — Settlements (1 ) — (1 ) — — — Net periodic cost $ 11 $ 11 $ 22 $ 14 $ 1 $ 15

Segment information (Tables)

Segment information (Tables)	9 Months Ended
	Sep. 30, 2017
Segment Reporting [Abstract]
Operations By Segment	The following tables present the Statement of Operations by segment: North America Commercial P&C Insurance North America Personal P&C Insurance North America Agricultural Insurance Overseas General Insurance Global Reinsurance Life Insurance Corporate Chubb Consolidated For the Three Months Ended September 30, 2017 (in millions of U.S. dollars) Net premiums written $ 3,089 $ 1,194 $ 926 $ 1,963 $ 191 $ 539 $ — $ 7,902 Net premiums earned 3,016 1,117 898 2,064 185 527 — 7,807 Losses and loss expenses 2,580 1,062 759 1,281 295 181 89 6,247 Policy benefits — — — — — 169 — 169 Policy acquisition costs 469 226 49 569 43 132 — 1,488 Administrative expenses 256 61 (1 ) 246 11 77 64 714 Underwriting income (loss) (289 ) (232 ) 91 (32 ) (164 ) (32 ) (153 ) (811 ) Net investment income (loss) 497 57 6 164 80 78 (69 ) 813 Other (income) expense (4 ) 1 — (10 ) (3 ) (19 ) (83 ) (118 ) Amortization expense of purchased intangibles — 4 8 11 — 1 41 65 Segment income (loss) $ 212 $ (180 ) $ 89 $ 131 $ (81 ) $ 64 $ (180 ) $ 55 Net realized gains (losses) including OTTI (10 ) (10 ) Interest expense 150 150 Chubb integration expenses 50 50 Income tax benefit (85 ) (85 ) Net loss $ (305 ) $ (70 ) North America Commercial P&C Insurance North America Personal P&C Insurance North America Agricultural Insurance Overseas General Insurance Global Reinsurance Life Insurance Corporate Chubb Consolidated For the Three Months Ended September 30, 2016 (in millions of U.S. dollars) Net premiums written $ 3,110 $ 1,011 $ 849 $ 1,940 $ 131 $ 532 $ — $ 7,573 Net premiums earned 3,086 1,081 819 2,034 156 512 — 7,688 Losses and loss expenses 1,863 594 683 843 49 174 63 4,269 Policy benefits — — — — — 155 — 155 Policy acquisition costs 522 229 48 546 42 127 — 1,514 Administrative expenses 275 89 1 261 12 77 57 772 Underwriting income (loss) 426 169 87 384 53 (21 ) (120 ) 978 Net investment income (loss) 477 53 5 152 67 71 (86 ) 739 Other (income) expense 3 2 — (6 ) — (20 ) (70 ) (91 ) Amortization expense (benefit) of purchased intangibles — 4 7 12 — 1 (20 ) 4 Segment income (loss) $ 900 $ 216 $ 85 $ 530 $ 120 $ 69 $ (116 ) $ 1,804 Net realized gains (losses) including OTTI 100 100 Interest expense 152 152 Chubb integration expenses 115 115 Income tax expense 277 277 Net income (loss) $ (560 ) $ 1,360 North America Commercial P&C Insurance North America Personal P&C Insurance North America Agricultural Insurance Overseas General Insurance Global Reinsurance Life Insurance Corporate Chubb Consolidated For the Nine Months Ended September 30, 2017 (in millions of U.S. dollars) Net premiums written $ 9,035 $ 3,433 $ 1,390 $ 6,169 $ 580 $ 1,586 $ — $ 22,193 Net premiums earned 9,156 3,296 1,256 6,018 542 1,548 — 21,816 Losses and loss expenses 6,376 2,378 976 3,316 435 556 145 14,182 Policy benefits — — — — — 500 — 500 Policy acquisition costs 1,420 673 75 1,653 137 376 — 4,334 Administrative expenses 728 192 (4 ) 734 33 226 187 2,096 Underwriting income (loss) 632 53 209 315 (63 ) (110 ) (332 ) 704 Net investment income (loss) 1,465 168 18 460 207 230 (220 ) 2,328 Other (income) expense (4 ) 3 1 (14 ) (2 ) (60 ) (257 ) (333 ) Amortization expense of purchased intangibles — 12 22 33 — 2 125 194 Segment income (loss) $ 2,101 $ 206 $ 204 $ 756 $ 146 $ 178 $ (420 ) $ 3,171 Net realized gains (losses) including OTTI 84 84 Interest expense 451 451 Chubb integration expenses 233 233 Income tax expense 243 243 Net income (loss) $ (1,263 ) $ 2,328 North America Commercial P&C Insurance North America Personal P&C Insurance North America Agricultural Insurance Overseas General Insurance Global Reinsurance Life Insurance Corporate Chubb Consolidated For the Nine Months Ended September 30, 2016 (in millions of U.S. dollars) Net premiums written $ 8,657 $ 3,113 $ 1,288 $ 6,012 $ 562 $ 1,575 $ — $ 21,207 Net premiums earned 9,130 3,245 1,169 6,082 543 1,521 — 21,690 Losses and loss expenses 5,581 1,916 937 2,953 225 498 87 12,197 Policy benefits — — — — — 427 — 427 Policy acquisition costs 1,549 747 77 1,586 142 386 — 4,487 Administrative expenses 840 275 (1 ) 801 40 226 192 2,373 Underwriting income (loss) 1,160 307 156 742 136 (16 ) (279 ) 2,206 Net investment income (loss) 1,371 155 15 445 199 207 (271 ) 2,121 Other (income) expense (6 ) 6 — (16 ) (3 ) (14 ) (59 ) (92 ) Amortization expense (benefit) of purchased intangibles — 16 22 36 — 2 (60 ) 16 Segment income (loss) $ 2,537 $ 440 $ 149 $ 1,167 $ 338 $ 203 $ (431 ) $ 4,403 Net realized gains (losses) including OTTI (510 ) (510 ) Interest expense 451 451 Chubb integration expenses 361 361 Income tax expense 556 556 Net income (loss) $ (2,309 ) $ 2,525

Earnings per share (Tables)

Earnings per share (Tables)	9 Months Ended
	Sep. 30, 2017
Earnings Per Share [Abstract]
Schedule Of Earnings Per Share, Basic And Diluted	Three Months Ended Nine Months Ended September 30 September 30 (in millions of U.S. dollars, except share and per share data) 2017 2016 2017 2016 Numerator: Net income (loss) $ (70 ) $ 1,360 $ 2,328 $ 2,525 Denominator: Denominator for basic earnings per share: Weighted-average shares outstanding 466,370,784 468,021,093 467,658,334 460,631,794 Denominator for diluted earnings per share: Share-based compensation plans — 3,375,269 3,961,572 3,439,017 Weighted-average shares outstanding and assumed conversions 466,370,784 471,396,362 471,619,906 464,070,811 Basic earnings (loss) per share $ (0.15 ) $ 2.90 $ 4.98 $ 5.48 Diluted earnings (loss) per share $ (0.15 ) $ 2.88 $ 4.94 $ 5.44 Potential anti-dilutive share conversions 2,045,829 1,306,710 1,673,777 1,635,337

Information provided in conne32

Information provided in connection with outstanding debt of subsidiaries (Tables)	9 Months Ended
	Sep. 30, 2017
Information Provided In Connection With Outstanding Debt Of Subsidiaries [Abstract]
Condensed Consolidating Balance Sheet	Condensed Consolidating Balance Sheet at September 30, 2017 (in millions of U.S. dollars) Chubb Limited (Parent Guarantor) Chubb INA Holdings Inc. (Subsidiary Issuer) Other Chubb Limited Subsidiaries Consolidating Adjustments and Eliminations Chubb Limited Consolidated Assets Investments $ — $ 169 $ 102,255 $ — $ 102,424 Cash (1) 1 — 1,174 (87 ) 1,088 Insurance and reinsurance balances receivable — — 11,076 (1,525 ) 9,551 Reinsurance recoverable on losses and loss expenses — — 27,007 (12,208 ) 14,799 Reinsurance recoverable on policy benefits — — 1,232 (1,039 ) 193 Value of business acquired — — 339 — 339 Goodwill and other intangible assets — — 22,265 — 22,265 Investments in subsidiaries 40,936 50,926 — (91,862 ) — Due from subsidiaries and affiliates, net 9,913 — — (9,913 ) — Other assets 61 276 20,699 (4,117 ) 16,919 Total assets $ 50,911 $ 51,371 $ 186,047 $ (120,751 ) $ 167,578 Liabilities Unpaid losses and loss expenses $ — $ — $ 75,688 $ (11,535 ) $ 64,153 Unearned premiums — — 19,150 (3,694 ) 15,456 Future policy benefits — — 6,346 (1,039 ) 5,307 Due to subsidiaries and affiliates, net — 9,697 216 (9,913 ) — Affiliated notional cash pooling programs (1) 85 2 — (87 ) — Repurchase agreements — — 1,408 — 1,408 Short-term debt — 1,020 — — 1,020 Long-term debt — 11,548 11 — 11,559 Trust preferred securities — 308 — — 308 Other liabilities 355 1,685 18,477 (2,621 ) 17,896 Total liabilities 440 24,260 121,296 (28,889 ) 117,107 Total shareholders’ equity 50,471 27,111 64,751 (91,862 ) 50,471 Total liabilities and shareholders’ equity $ 50,911 $ 51,371 $ 186,047 $ (120,751 ) $ 167,578 (1) Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At September 30, 2017 , the cash balance of one or more entities was negative; however, the overall Pool balances were positive. Condensed Consolidating Balance Sheet at December 31, 2016 (in millions of U.S. dollars) Chubb Limited (Parent Guarantor) Chubb INA Holdings Inc. (Subsidiary Issuer) Other Chubb Limited Subsidiaries Consolidating Adjustments and Eliminations Chubb Limited Consolidated Assets Investments $ 27 $ 485 $ 98,582 $ — $ 99,094 Cash (1) 1 1 1,965 (982 ) 985 Insurance and reinsurance balances receivable — — 10,498 (1,528 ) 8,970 Reinsurance recoverable on losses and loss expenses — — 24,496 (10,919 ) 13,577 Reinsurance recoverable on policy benefits — — 1,153 (971 ) 182 Value of business acquired — — 355 — 355 Goodwill and other intangible assets — — 22,095 — 22,095 Investments in subsidiaries 38,408 49,509 — (87,917 ) — Due from subsidiaries and affiliates, net 10,482 — — (10,482 ) — Other assets 3 436 18,442 (4,353 ) 14,528 Total assets $ 48,921 $ 50,431 $ 177,586 $ (117,152 ) $ 159,786 Liabilities Unpaid losses and loss expenses $ — $ — $ 70,683 $ (10,143 ) $ 60,540 Unearned premiums — — 18,538 (3,759 ) 14,779 Future policy benefits — — 6,007 (971 ) 5,036 Due to subsidiaries and affiliates, net — 10,209 273 (10,482 ) — Affiliated notional cash pooling programs (1) 363 619 — (982 ) — Repurchase agreements — — 1,403 — 1,403 Short-term debt — 500 — — 500 Long-term debt — 12,599 11 — 12,610 Trust preferred securities — 308 — — 308 Other liabilities 283 1,582 17,368 (2,898 ) 16,335 Total liabilities 646 25,817 114,283 (29,235 ) 111,511 Total shareholders’ equity 48,275 24,614 63,303 (87,917 ) 48,275 Total liabilities and shareholders’ equity $ 48,921 $ 50,431 $ 177,586 $ (117,152 ) $ 159,786 (1) Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At December 31, 2016 , the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
Condensed Consolidating Statement Of Operations and Comprehensive Income	Condensed Consolidating Statements of Operations and Comprehensive Income For the Three Months Ended September 30, 2017 Chubb Limited (Parent Guarantor) Chubb INA Holdings Inc. (Subsidiary Issuer) Other Chubb Limited Subsidiaries Consolidating Adjustments and Eliminations Chubb Limited Consolidated (in millions of U.S. dollars) Net premiums written $ — $ — $ 7,902 $ — $ 7,902 Net premiums earned — — 7,807 — 7,807 Net investment income 1 3 809 — 813 Equity in earnings of subsidiaries (127 ) 212 — (85 ) — Net realized gains (losses) including OTTI — (8 ) (2 ) — (10 ) Losses and loss expenses — — 6,247 — 6,247 Policy benefits — — 169 — 169 Policy acquisition costs and administrative expenses 20 16 2,166 — 2,202 Interest (income) expense (84 ) 208 26 — 150 Other (income) expense (5 ) 9 (122 ) — (118 ) Amortization of purchased intangibles — — 65 — 65 Chubb integration expenses 7 1 42 — 50 Income tax expense (benefit) 6 (89 ) (2 ) — (85 ) Net income (loss) $ (70 ) $ 62 $ 23 $ (85 ) $ (70 ) Comprehensive income $ 629 $ 748 $ 724 $ (1,472 ) $ 629 Condensed Consolidating Statements of Operations and Comprehensive Income For the Three Months Ended September 30, 2016 Chubb Limited (Parent Guarantor) Chubb INA Holdings Inc. (Subsidiary Issuer) Other Chubb Limited Subsidiaries Consolidating Adjustments and Eliminations Chubb Limited Consolidated (in millions of U.S. dollars) Net premiums written $ — $ — $ 7,573 $ — $ 7,573 Net premiums earned — — 7,688 — 7,688 Net investment income 1 2 736 — 739 Equity in earnings of subsidiaries 1,292 748 — (2,040 ) — Net realized gains (losses) including OTTI — (2 ) 102 — 100 Losses and loss expenses — — 4,269 — 4,269 Policy benefits — — 155 — 155 Policy acquisition costs and administrative expenses 15 12 2,259 — 2,286 Interest (income) expense (93 ) 233 12 — 152 Other (income) expense (7 ) 6 (90 ) — (91 ) Amortization of purchased intangibles — — 4 — 4 Chubb integration expenses 12 16 87 — 115 Income tax expense (benefit) 6 (136 ) 407 — 277 Net income $ 1,360 $ 617 $ 1,423 $ (2,040 ) $ 1,360 Comprehensive income $ 1,376 $ 627 $ 1,439 $ (2,066 ) $ 1,376 Condensed Consolidating Statements of Operations and Comprehensive Income For the Nine Months Ended September 30, 2017 Chubb Limited (Parent Guarantor) Chubb INA Holdings Inc. (Subsidiary Issuer) Other Chubb Limited Subsidiaries Consolidating Adjustments and Eliminations Chubb Limited Consolidated (in millions of U.S. dollars) Net premiums written $ — $ — $ 22,193 $ — $ 22,193 Net premiums earned — — 21,816 — 21,816 Net investment income 3 10 2,315 — 2,328 Equity in earnings of subsidiaries 2,153 1,578 — (3,731 ) — Net realized gains (losses) including OTTI (2 ) (22 ) 108 — 84 Losses and loss expenses — — 14,182 — 14,182 Policy benefits — — 500 — 500 Policy acquisition costs and administrative expenses 56 28 6,346 — 6,430 Interest (income) expense (252 ) 641 62 — 451 Other (income) expense (7 ) 34 (360 ) — (333 ) Amortization of purchased intangibles — — 194 — 194 Chubb integration expenses 13 54 166 — 233 Income tax expense (benefit) 16 (288 ) 515 — 243 Net income $ 2,328 $ 1,097 $ 2,634 $ (3,731 ) $ 2,328 Comprehensive income $ 3,711 $ 2,459 $ 4,018 $ (6,477 ) $ 3,711 Condensed Consolidating Statements of Operations and Comprehensive Income For the Nine Months Ended September 30, 2016 Chubb Limited (Parent Guarantor) Chubb INA Holdings Inc. (Subsidiary Issuer) Other Chubb Limited Subsidiaries Consolidating Adjustments and Eliminations Chubb Limited Consolidated (in millions of U.S. dollars) Net premiums written $ — $ — $ 21,207 $ — $ 21,207 Net premiums earned — — 21,690 — 21,690 Net investment income 3 9 2,109 — 2,121 Equity in earnings of subsidiaries 2,331 1,803 — (4,134 ) — Net realized gains (losses) including OTTI (1 ) (3 ) (506 ) — (510 ) Losses and loss expenses — — 12,197 — 12,197 Policy benefits — — 427 — 427 Policy acquisition costs and administrative expenses 48 144 6,668 — 6,860 Interest (income) expense (266 ) 681 36 — 451 Other (income) expense (20 ) 26 (98 ) — (92 ) Amortization of purchased intangibles — — 16 — 16 Chubb integration expenses 29 56 276 — 361 Income tax expense (benefit) 17 (323 ) 862 — 556 Net income $ 2,525 $ 1,225 $ 2,909 $ (4,134 ) $ 2,525 Comprehensive income $ 4,457 $ 2,687 $ 4,841 $ (7,528 ) $ 4,457
Condensed Consolidating Statement of Cash Flows	Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2017 Chubb Limited (Parent Guarantor) Chubb INA Holdings Inc. (Subsidiary Issuer) Other Chubb Consolidating Adjustments and Eliminations Chubb Limited Consolidated (in millions of U.S. dollars) Net cash flows from operating activities $ 639 $ 1,472 $ 3,341 $ (2,041 ) $ 3,411 Cash flows from investing activities Purchases of fixed maturities available for sale — (9 ) (18,469 ) — (18,478 ) Purchases of fixed maturities held to maturity — — (262 ) — (262 ) Purchases of equity securities — — (125 ) — (125 ) Sales of fixed maturities available for sale — 99 9,116 — 9,215 Sales of equity securities — — 152 — 152 Maturities and redemptions of fixed maturities available for sale — 22 7,677 — 7,699 Maturities and redemptions of fixed maturities held to maturity — — 644 — 644 Net change in short-term investments — 197 (153 ) — 44 Net derivative instruments settlements — (13 ) (157 ) — (170 ) Other — 6 (68 ) — (62 ) Net cash flows from (used for) investing activities — 302 (1,645 ) — (1,343 ) Cash flows from financing activities Dividends paid on Common Shares (978 ) — — — (978 ) Common Shares repurchased — — (707 ) — (707 ) Repayment of long-term debt — (500 ) — — (500 ) Proceeds from issuance of repurchase agreements — — 1,798 — 1,798 Repayment of repurchase agreements — — (1,793 ) — (1,793 ) Proceeds from share-based compensation plans — — 109 — 109 Dividend to parent company — — (2,041 ) 2,041 — Advances (to) from affiliates 617 (658 ) 41 — — Net payments to affiliated notional cash pooling programs (1) (278 ) (617 ) — 895 — Policyholder contract deposits — — 312 — 312 Policyholder contract withdrawals — — (211 ) — (211 ) Net cash flows used for financing activities (639 ) (1,775 ) (2,492 ) 2,936 (1,970 ) Effect of foreign currency rate changes on cash and cash equivalents — — 5 — 5 Net increase (decrease) in cash — (1 ) (791 ) 895 103 Cash – beginning of period (1) 1 1 1,965 (982 ) 985 Cash – end of period (1) $ 1 $ — $ 1,174 $ (87 ) $ 1,088 (1) Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At September 30, 2017 and December 31, 2016, the cash balance of one or more entities was negative; however, the overall Pool balances were positive. Condensed Consolidating Statement of Cash Flows Nine Months Ended September 30, 2016 Chubb Limited (Parent Guarantor) Chubb INA Holdings Inc. (Subsidiary Issuer) Other Chubb Limited Subsidiaries Consolidating Adjustments and Eliminations Chubb Limited Consolidated (in millions of U.S. dollars) Net cash flows from operating activities $ 3,399 $ 3,892 $ 3,918 $ (7,372 ) $ 3,837 Cash flows from investing activities Purchases of fixed maturities available for sale — (154 ) (23,683 ) — (23,837 ) Purchases of fixed maturities held to maturity — — (189 ) — (189 ) Purchases of equity securities — — (100 ) — (100 ) Sales of fixed maturities available for sale — 66 13,797 — 13,863 Sales of equity securities — — 963 — 963 Maturities and redemptions of fixed maturities available for sale — 59 6,877 — 6,936 Maturities and redemptions of fixed maturities held to maturity — — 627 — 627 Net change in short-term investments — 7,627 4,239 — 11,866 Net derivative instruments settlements — (10 ) (171 ) — (181 ) Acquisition of subsidiaries (net of cash acquired of $71) — (14,282 ) 34 — (14,248 ) Capital contribution (2,330 ) (20 ) (2,330 ) 4,680 — Other — (3 ) 29 — 26 Net cash flows from (used for) investing activities (2,330 ) (6,717 ) 93 4,680 (4,274 ) Cash flows from financing activities Dividends paid on Common Shares (851 ) — — — (851 ) Proceeds from issuance of repurchase agreements — — 1,457 — 1,457 Repayment of repurchase agreements — — (1,455 ) — (1,455 ) Proceeds from share-based compensation plans, including windfall tax benefits — — 117 — 117 Dividend to parent company — — (7,372 ) 7,372 — Advances (to) from affiliates (258 ) 219 39 — — Capital contribution — 2,330 2,350 (4,680 ) — Net proceeds from (payments to) affiliated notional cash pooling programs (1) 45 280 — (325 ) — Policyholder contract deposits — — 473 — 473 Policyholder contract withdrawals — — (247 ) — (247 ) Other — (4 ) — — (4 ) Net cash flows from (used for) financing activities (1,064 ) 2,825 (4,638 ) 2,367 (510 ) Effect of foreign currency rate changes on cash and cash equivalents — — 42 — 42 Net increase (decrease) in cash 5 — (585 ) (325 ) (905 ) Cash – beginning of period (1) 1 2 2,743 (971 ) 1,775 Cash – end of period (1) $ 6 $ 2 $ 2,158 $ (1,296 ) $ 870 (1) Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At September 30, 2016 and December 31, 2015, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

General Adoption of New Account

General Adoption of New Accounting Pronouncements (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax benefit	$ (85)	$ 277	$ 243	$ 556
Accounting Standards Update 2016-09 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Income tax benefit	$ 14		$ 44

General Goodwill (Details)

General Goodwill (Details) $ in Millions	9 Months Ended
	Sep. 30, 2017USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill, Period Increase (Decrease)	$ 375

General Schedule of long-term d

General Schedule of long-term debt (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Apr. 14, 2017	Feb. 28, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Short-term debt	$ 1,020			$ 500
Junior Subordinated Debt [Member] | Chubb INA Capital Securities Due 2037 [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 1,000
Debt Instrument, Interest Rate, Stated Percentage	3.61%	6.375%
Junior Subordinated Debt [Member] | Chubb INA Capital Securities Due 2037 [Member] | London Interbank Offered Rate (LIBOR) [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	2.25%
Senior Notes [Member] | INA Senior Notes Due February 2017 [Member]
Debt Instrument [Line Items]
Short-term debt			$ 500
Debt Instrument, Interest Rate, Stated Percentage			5.70%
Senior Notes [Member] | INA Senior Notes Due March 2018 [Member]
Debt Instrument [Line Items]
Short-term debt	$ 300
Debt Instrument, Face Amount	$ 300
Debt Instrument, Interest Rate, Stated Percentage	5.80%
Senior Notes [Member] | Chubb INA Senior Notes Due 2018 [Member]
Debt Instrument [Line Items]
Short-term debt	$ 616
Debt Instrument, Face Amount	$ 600
Debt Instrument, Interest Rate, Stated Percentage	5.75%
Senior Notes [Member] | Chubb INA Senior Notes Due August 2018 [Member]
Debt Instrument [Line Items]
Short-term debt	$ 104
Debt Instrument, Face Amount	$ 100
Debt Instrument, Interest Rate, Stated Percentage	6.60%

Acquisitions Acquisitions (narr

Acquisitions Acquisitions (narrative) (Details) - USD ($) $ in Millions	Jan. 14, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Business Acquisition [Line Items]
Goodwill		$ 15,707		$ 15,332
The Chubb Corporation [Member]
Business Acquisition [Line Items]
Purchase price	$ 29,500
Cash consideration paid by Chubb Limited to common shareholders of Chubb Corp	14,300
Equity Issued in Business Combination, Fair Value Disclosure	15,200
Business Combination, Consideration Transferred	29,800
Goodwill	10,500
Additional Paid-in Capital [Member]
Business Acquisition [Line Items]
Attributed Value Equity Awards Assumed in Acquisition		(311)	$ (365)
Additional Paid-in Capital [Member] | The Chubb Corporation [Member]
Business Acquisition [Line Items]
Attributed Value Equity Awards Assumed in Acquisition	$ 323	$ 0	$ 323

Supplemental Financial Informat

Supplemental Financial Information for Acquisition (Details) - The Chubb Corporation [Member] - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2016	Sep. 30, 2016
Business Acquisition [Line Items]
Actual Revenue of Chubb Corp since Acquisition Date	$ 2,656	$ 7,888
Actual Net Income of Chubb Corp since Acquisition Date	483	1,064
Pro Forma Total Revenues	8,521	23,758
Pro Forma Net Income	$ 1,345	$ 2,591
Pro Forma Earnings Per Share, Basic	$ 2.87	$ 5.54
Pro Forma Earnings Per Share, Diluted	$ 2.85	$ 5.50

Investments (Narrative) (Detail

Investments (Narrative) (Detail) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017USD ($)Security	Sep. 30, 2016USD ($)	Sep. 30, 2017USD ($)Security	Sep. 30, 2016USD ($)	Dec. 31, 2016USD ($)
Investment [Line Items]
Net unrealized appreciation (depreciation) included in OCI	$ 1	$ 13	$ (2)	$ 57
Unrealized appreciation(depreciation) portion of AOCI with OTTI included in AOCI	$ 7		$ 7		$ 10
Percentage of mortgage-backed securities represented by investments in US government agency bonds	82.00%		82.00%		81.00%
Total number of fixed maturities | Security	30,933		30,933
Number of equity securities in an unrealized loss position | Security	59		59
Total number of equity securities | Security	317		317
Largest single unrealized loss in the equity securities	$ (1)		$ (1)
Restricted assets in fixed maturities and short-term investments	22,800		22,800		$ 20,100
Restricted assets in cash	$ 105		$ 105		$ 103
Moodys Historical Mean Recovery Rate			42.00%
Company Assumed Recovery Rate			32.00%
Number of fixed maturities in an unrealized loss position | Security	7,455		7,455
Largest single unrealized loss in the fixed maturities	$ 7		$ 7
Corporate [Member]
Investment [Line Items]
Credit losses recognized in net income	3	4	5	28
Collateralized Mortgage Backed Securities [Member]
Investment [Line Items]
Credit losses recognized in net income	$ 0	$ 1	$ 0	$ 1

Investments Investments (Schedu

Investments Investments (Schedule Of Amortized Cost and Fair Value of Available-for-sale Securities and Related OTTI Recognized in AOCI) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Available for sale, at amortized cost	$ 82,254	$ 79,536
Available-for-sale,Gross Unrealized Gain	1,811	1,455
Available-for-sale, Gross Unrealized Depreciation	(379)	(876)
Available for sale, Fair Value	83,686	80,115
Available for sale, OTTI recognized in AOCI	(7)	(14)
US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, at amortized cost	3,571	2,883
Available-for-sale,Gross Unrealized Gain	38	32
Available-for-sale, Gross Unrealized Depreciation	(27)	(45)
Available for sale, Fair Value	3,582	2,870
Available for sale, OTTI recognized in AOCI	0	0
Foreign Government Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, at amortized cost	22,516	20,929
Available-for-sale,Gross Unrealized Gain	690	636
Available-for-sale, Gross Unrealized Depreciation	(107)	(125)
Available for sale, Fair Value	23,099	21,440
Available for sale, OTTI recognized in AOCI	(2)	(5)
Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, at amortized cost	24,555	23,736
Available-for-sale,Gross Unrealized Gain	754	580
Available-for-sale, Gross Unrealized Depreciation	(83)	(167)
Available for sale, Fair Value	25,226	24,149
Available for sale, OTTI recognized in AOCI	(4)	(8)
Collateralized Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, at amortized cost	15,369	14,066
Available-for-sale,Gross Unrealized Gain	157	135
Available-for-sale, Gross Unrealized Depreciation	(115)	(194)
Available for sale, Fair Value	15,411	14,007
Available for sale, OTTI recognized in AOCI	(1)	(1)
US States and Political Subdivisions Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Available for sale, at amortized cost	16,243	17,922
Available-for-sale,Gross Unrealized Gain	172	72
Available-for-sale, Gross Unrealized Depreciation	(47)	(345)
Available for sale, Fair Value	16,368	17,649
Available for sale, OTTI recognized in AOCI	$ 0	$ 0

Investments (Schedule Of Amorti

Investments (Schedule Of Amortized Cost And Fair Value Of HTM Fixed Maturities And Related OTTI Recognized In Accumulated Other Comprehensive Income) (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Investment [Line Items]
Held to maturity, Amortized Cost	$ 10,160	$ 10,644
Held to maturity, Gross Unrealized Appreciation	216	148
Held to maturity, Gross Unrealized Depreciation	(11)	(122)
Held to maturity, at Fair Value	10,365	10,670
Held to maturity, OTTI recognized in AOCI		0
U.S. Treasury And Agency [Member]
Investment [Line Items]
Held to maturity, Amortized Cost	611	655
Held to maturity, Gross Unrealized Appreciation	13	9
Held to maturity, Gross Unrealized Depreciation	(3)	(3)
Held to maturity, at Fair Value	621	661
Held to maturity, OTTI recognized in AOCI	0	0
Foreign [Member]
Investment [Line Items]
Held to maturity, Amortized Cost	616	640
Held to maturity, Gross Unrealized Appreciation	28	28
Held to maturity, Gross Unrealized Depreciation	0	(1)
Held to maturity, at Fair Value	644	667
Held to maturity, OTTI recognized in AOCI	0	0
Corporate [Member]
Investment [Line Items]
Held to maturity, Amortized Cost	2,531	2,771
Held to maturity, Gross Unrealized Appreciation	63	50
Held to maturity, Gross Unrealized Depreciation	(5)	(26)
Held to maturity, at Fair Value	2,589	2,795
Held to maturity, OTTI recognized in AOCI	0	0
Collateralized Mortgage Backed Securities [Member]
Investment [Line Items]
Held to maturity, Amortized Cost	1,223	1,393
Held to maturity, Gross Unrealized Appreciation	35	35
Held to maturity, Gross Unrealized Depreciation	0	0
Held to maturity, at Fair Value	1,258	1,428
Held to maturity, OTTI recognized in AOCI	0	0
States, Municipalities, And Political Subdivisions [Member]
Investment [Line Items]
Held to maturity, Amortized Cost	5,179	5,185
Held to maturity, Gross Unrealized Appreciation	77	26
Held to maturity, Gross Unrealized Depreciation	(3)	(92)
Held to maturity, at Fair Value	5,253	5,119
Held to maturity, OTTI recognized in AOCI	$ 0	$ 0

Investments (Schedule Of Fixed

Investments (Schedule Of Fixed Maturities By Contractual Maturity) (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Available for sale, Due in 1 year or less, Amortized Cost	$ 3,532	$ 3,892
Available for sale, Due after 1 year through 5 years, Amortized Cost	24,918	24,027
Available for sale, Due after 5 years though 10 years, Amortized Cost	28,009	27,262
Available for sale, Due after 10 years, Amortized Cost	10,426	10,289
Available for sale, Subtotal, Amortized Cost	66,885	65,470
Available for sale, Mortgage-backed securities, Amortized Cost	15,369	14,066
Available for sale, at amortized cost	82,254	79,536
Available for sale, Due in 1 year or less, Fair Value	3,556	3,913
Available for sale, Due after 1 year through 5 years, Fair Value	25,397	24,429
Available for sale, Due after 5 years through 10 years, Fair Value	28,488	27,379
Available for sale, Due after 10 years, Fair Value	10,834	10,387
Available for sale, Subtotal, Fair Value	68,275	66,108
Available for sale, Mortgage backed securities, Fair Value	15,411	14,007
Available for sale, Fair Value	83,686	80,115
Held to maturity, Due in 1 year or less, Amortized Cost	822	430
Held to maturity, Due after 1 year through 5 years, Amortized Cost	2,479	2,646
Held to maturity, Due after 5 years through 10 years, Amortized Cost	2,821	2,969
Held to maturity, Due after 10 years, Amortized Cost	2,815	3,206
Held to maturity, Subtotal, Amortized Cost	8,937	9,251
Held to maturity, Mortgage backed securities, Amortized Cost	1,223	1,393
Held to maturity, Amortized Cost	10,160	10,644
Held to maturity, Due in 1 year or less, Fair Value	828	435
Held to maturity, Due after 1 year through 5, Fair Value	2,524	2,691
Held to maturity, Due after 5 years through 10 years, Fair Value	2,866	2,944
Held to maturity, Due after 10 years, Fair Value	2,889	3,172
Held to maturity, Subtotal, Fair Value	9,107	9,242
Held to maturity, Mortgage backed securities, Fair Value	1,258	1,428
Held to maturity, Fair Value	$ 10,365	$ 10,670

Investments (Schedule Of Cost A

Investments (Schedule Of Cost And Fair Value Of Equity Securities) (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Cost	$ 723	$ 706
Gross unrealized appreciation	195	129
Gross unrealized depreciation	(8)	(21)
Equity securities, at fair value	$ 910	$ 814

Investments (Net Realized Gains

Investments (Net Realized Gains (Losses) And Losses Included In Net Realized Gains (Losses) And 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
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment (OTTI) losses gross	$ (8)	$ (12)	$ (36)	$ (99)
OTTI on fixed maturities recognized in OCI (pre-tax)	0	0	1	8
Foreign exchange gains	15	29	10	46
Derivative instrument	(22)	48	68	(442)
Fair Value Adjustments On Insurance Derivative Gains Losses	54	89	265	(270)
Net realized gains (losses)	(10)	100	84	(510)
Investment and embedded derivative instruments
Gain (Loss) on Investments [Line Items]
Derivative instrument	(14)	1	(24)	(85)
S&P put options and futures
Gain (Loss) on Investments [Line Items]
Derivative instrument	(57)	(45)	(169)	(88)
Other derivative instruments
Gain (Loss) on Investments [Line Items]
Derivative instrument	(5)	3	(4)	1
Fixed Maturities [Member]
Gain (Loss) on Investments [Line Items]
Other-than-temporary impairment (OTTI) losses gross	(5)	(7)	(16)	(85)
OTTI on fixed maturities recognized in OCI (pre-tax)	0	0	1	8
OTTI on fixed maturities, net	(5)	(7)	(15)	(77)
Fixed maturities, Gross realized gains excluding OTTI	30	47	109	149
Fixed maturities, Gross realized losses excluding OTTI	(19)	(13)	(77)	(228)
Total fixed maturities	6	27	17	(156)
Equity Securities [Member]
Gain (Loss) on Investments [Line Items]
OTTI on equity securities	(1)	(1)	(9)	(7)
Equity Securities, Gross realized gains excluding OTTI	6	19	21	63
Equity Securities, Gross realized losses excluding OTTI	(1)	(12)	(2)	(17)
Total equity securities	4	6	10	39
Other Investments [Member]
Gain (Loss) on Investments [Line Items]
OTTI on equity securities	(2)	(4)	(11)	(7)
Other	$ (11)	$ (6)	$ (10)	$ 10

Investments (Roll-Forward Of Pr

Investments (Roll-Forward Of Pre-Tax Credit Losses Related To Fixed Maturities For Which Portion Of Other-Than-Temporary Impairment Was Recognized In 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
Roll-Forward Of Pre-Tax Credit Losses Related To Fixed Maturities For Which Portion Of Other-Than-Temporary Impairment Was Recognized In Other Comprehensive Income [Roll Forward]
Balance of credit losses related to securities still held – beginning of period	$ 29	$ 51	$ 35	$ 53
Additions where no OTTI was previously recorded	2	4	3	16
Additions where an OTTI was previously recorded	1	1	2	13
Reductions for securities sold during the period	(7)	(11)	(15)	(37)
Balance of credit losses related to securities still held – end of period	$ 25	$ 45	$ 25	$ 45

Investments (Aggregate Fair Val

Investments (Aggregate Fair Value And Gross Unrealized Loss By Length Of Time Security Has Continuously Been In Unrealized Loss Position) (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Investment [Line Items]
Fair Value, 0-12 Months	$ 22,243	$ 43,641
Gross Unrealized Loss, 0-12 Months	(287)	(959)
Fair Value, Over 12 Months	3,926	1,310
Gross Unrealized Loss, Over 12 Months	(120)	(78)
Total Fair Value	26,169	44,951
Total Gross Unrealized Loss	(407)	(1,037)
U.S. Treasury And Agency [Member]
Investment [Line Items]
Fair Value, 0-12 Months	1,763	2,216
Gross Unrealized Loss, 0-12 Months	(13)	(48)
Fair Value, Over 12 Months	656	0
Gross Unrealized Loss, Over 12 Months	(17)	0
Total Fair Value	2,419	2,216
Total Gross Unrealized Loss	(30)	(48)
Foreign [Member]
Investment [Line Items]
Fair Value, 0-12 Months	5,353	5,918
Gross Unrealized Loss, 0-12 Months	(85)	(99)
Fair Value, Over 12 Months	894	386
Gross Unrealized Loss, Over 12 Months	(22)	(27)
Total Fair Value	6,247	6,304
Total Gross Unrealized Loss	(107)	(126)
Corporate [Member]
Investment [Line Items]
Fair Value, 0-12 Months	3,373	7,021
Gross Unrealized Loss, 0-12 Months	(48)	(149)
Fair Value, Over 12 Months	788	641
Gross Unrealized Loss, Over 12 Months	(40)	(44)
Total Fair Value	4,161	7,662
Total Gross Unrealized Loss	(88)	(193)
Collateralized Mortgage Backed Securities [Member]
Investment [Line Items]
Fair Value, 0-12 Months	6,946	8,638
Gross Unrealized Loss, 0-12 Months	(96)	(189)
Fair Value, Over 12 Months	749	234
Gross Unrealized Loss, Over 12 Months	(19)	(5)
Total Fair Value	7,695	8,872
Total Gross Unrealized Loss	(115)	(194)
States, Municipalities, And Political Subdivisions [Member]
Investment [Line Items]
Fair Value, 0-12 Months	4,548	19,448
Gross Unrealized Loss, 0-12 Months	(28)	(435)
Fair Value, Over 12 Months	839	49
Gross Unrealized Loss, Over 12 Months	(22)	(2)
Total Fair Value	5,387	19,497
Total Gross Unrealized Loss	(50)	(437)
Fixed Maturities [Member]
Investment [Line Items]
Fair Value, 0-12 Months	21,983	43,241
Gross Unrealized Loss, 0-12 Months	(270)	(920)
Fair Value, Over 12 Months	3,926	1,310
Gross Unrealized Loss, Over 12 Months	(120)	(78)
Total Fair Value	25,909	44,551
Total Gross Unrealized Loss	(390)	(998)
Equity Securities [Member]
Investment [Line Items]
Fair Value, 0-12 Months	103	199
Gross Unrealized Loss, 0-12 Months	(8)	(21)
Fair Value, Over 12 Months	0	0
Gross Unrealized Loss, Over 12 Months	0	0
Total Fair Value	103	199
Total Gross Unrealized Loss	(8)	(21)
Other Long-term Investments [Member]
Investment [Line Items]
Fair Value, 0-12 Months	157	201
Gross Unrealized Loss, 0-12 Months	(9)	(18)
Fair Value, Over 12 Months	0	0
Gross Unrealized Loss, Over 12 Months	0	0
Total Fair Value	157	201
Total Gross Unrealized Loss	$ (9)	$ (18)

Investments (Schedule Of Compon

Investments (Schedule Of Components Of Restricted Assets) (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Investments, Debt and Equity Securities [Abstract]
Trust funds	$ 16,391	$ 13,880
Deposits with U.S. regulatory authorities	2,361	2,203
Deposits with non-U.S. regulatory authorities	2,294	2,191
Assets pledged under repurchase agreements	1,441	1,461
Other pledged assets	377	435
Total restricted assets	$ 22,864	$ 20,170

Fair value measurements Fair Va

Fair value measurements Fair Value Measurements (narrative) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value, Level 1 to Level 2 transfers, Amount	$ 0	$ 0	$ 0	$ 0
Fair Value, Level 2 to Level 1 Transfers, Amount	0	$ 0	$ 0	$ 0
Realized Gain Losses As A Result of Annuitization Changes	$ 94
Minimum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Notice Period For Redemption For Alternative Investments Investment Funds			5 days
Maximum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Notice Period For Redemption For Alternative Investments Investment Funds			120 days

Fair Value Measurements (Financ

Fair Value Measurements (Financial Instruments Measured At Fair Value On Recurring Basis) (Detail) - USD ($) $ in Millions	Sep. 30, 2017		Jun. 30, 2017	[1]	Dec. 31, 2016		Sep. 30, 2016	[3],[4]	Jun. 30, 2016	[3]	Dec. 31, 2015	[4]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale, Fair Value	$ 83,686				$ 80,115
Equity securities, at fair value	910				814
Other Investments	4,677				4,519
Securities lending collateral	1,757				1,092
Investment Funds Limited Partnerships Partially Owned Investment Companies Fair Value [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Other Investments	3,669				3,626
Other Investments [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Other Investments	18				25
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale, Fair Value	83,686				80,115
Equity securities, at fair value	910				814
Short-term investments	2,991				3,002
Other Investments	990				868
Securities lending collateral	1,757				1,092
Investment derivative instruments, assets	15				31
Other Derivative Instruments Fair Value					3
Separate Account Assets	2,514				1,879
Total assets measured at fair value	92,863				87,804
Investment derivative instruments, liabilities	37				54
Other derivative instruments, liability	27				13
Liabilities, Fair Value Disclosure, Recurring	367				626
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale, Fair Value	2,941				2,175
Equity securities, at fair value	858				773
Short-term investments	1,804				1,757
Other Investments	446				384
Investment derivative instruments, assets	15				31
Other Derivative Instruments Fair Value					3
Separate Account Assets	2,414				1,784
Total assets measured at fair value	8,478				6,907
Investment derivative instruments, liabilities	37				54
Other derivative instruments, liability	25
Liabilities, Fair Value Disclosure, Recurring	62				54
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale, Fair Value	79,692				77,140
Short-term investments	1,187				1,220
Other Investments	292				259
Securities lending collateral	1,757				1,092
Separate Account Assets	100				95
Total assets measured at fair value	83,028				79,806
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale, Fair Value	1,053				800
Equity securities, at fair value	52				41
Short-term investments					25
Other Investments	252				225
Total assets measured at fair value	1,357				1,091
Other derivative instruments, liability	2				13
Liabilities, Fair Value Disclosure, Recurring	305				572
Fair Value, Measurements, Recurring [Member] | U.S. Treasury And Agency [Member] | Estimate of Fair Value Measurement [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale, Fair Value	3,582				2,870
Fair Value, Measurements, Recurring [Member] | U.S. Treasury And Agency [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale, Fair Value	2,941				2,175
Fair Value, Measurements, Recurring [Member] | U.S. Treasury And Agency [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale, Fair Value	641				695
Fair Value, Measurements, Recurring [Member] | Foreign [Member] | Estimate of Fair Value Measurement [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale, Fair Value	23,099				21,440
Fair Value, Measurements, Recurring [Member] | Foreign [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale, Fair Value	23,009				21,366
Fair Value, Measurements, Recurring [Member] | Foreign [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale, Fair Value	90				74
Fair Value, Measurements, Recurring [Member] | Corporate [Member] | Estimate of Fair Value Measurement [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale, Fair Value	25,226				24,149
Fair Value, Measurements, Recurring [Member] | Corporate [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale, Fair Value	24,307				23,468
Fair Value, Measurements, Recurring [Member] | Corporate [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale, Fair Value	919				681
Fair Value, Measurements, Recurring [Member] | Collateralized Mortgage Backed Securities [Member] | Estimate of Fair Value Measurement [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale, Fair Value	15,411				14,007
Fair Value, Measurements, Recurring [Member] | Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale, Fair Value	15,367				13,962
Fair Value, Measurements, Recurring [Member] | Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale, Fair Value	44				45
Fair Value, Measurements, Recurring [Member] | States, Municipalities, And Political Subdivisions [Member] | Estimate of Fair Value Measurement [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale, Fair Value	16,368				17,649
Fair Value, Measurements, Recurring [Member] | States, Municipalities, And Political Subdivisions [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Available for sale, Fair Value	16,368				17,649
Guaranteed Minimum Income Benefit [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	303	[1],[2]	$ 357		559	[2]	$ 883		$ 971		$ 609
Guaranteed Minimum Income Benefit [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	303				559
Guaranteed Minimum Income Benefit [Member] | Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value	$ 303				559
Guaranteed Minimum Income Benefit [Member] | Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring Basis [Line Items]
Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value					$ 559
[1]	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $635 million at September 30, 2017, and $684 million at June 30, 2017, which includes a fair value derivative adjustment of $303 million and $357 million, respectively.
[2]	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $635 million at September 30, 2017, and $853 million at December 31, 2016, which includes a fair value derivative adjustment of $303 million and $559 million, respectively
[3]	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $1.2 billion at September 30, 2016, and $1.3 billion at June 30, 2016, which includes a fair value derivative adjustment of $883 million and $971 million, respectively.
[4]	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $1.2 billion at September 30, 2016, and $888 million at December 31, 2015, which includes a fair value derivative adjustment of $883 million and $609 million, respectively.

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value And Maximum Future Funding Commitments Related To Investments) (Detail) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Maximum future funding commitments	$ 1,730	$ 2,040
Fair Value	3,669	3,627
Financial [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Maximum future funding commitments	367	428
Fair Value	$ 566	$ 548
Financial [Member] | Minimum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period	5 years	5 years
Financial [Member] | Maximum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period	9 years	9 years
Real Assets [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Maximum future funding commitments	$ 148	$ 230
Fair Value	$ 635	$ 536
Real Assets [Member] | Minimum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period	3 years	3 years
Real Assets [Member] | Maximum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period	7 years	7 years
Distressed [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Maximum future funding commitments	$ 157	$ 179
Fair Value	$ 327	$ 485
Distressed [Member] | Minimum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period	5 years	5 years
Distressed [Member] | Maximum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period	9 years	9 years
Private Credit [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Maximum future funding commitments	$ 329	$ 259
Fair Value	$ 216	$ 236
Private Credit [Member] | Minimum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period	3 years	3 years
Private Credit [Member] | Maximum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period	7 years	7 years
Traditional [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Maximum future funding commitments	$ 729	$ 930
Fair Value	$ 1,643	$ 1,550
Traditional [Member] | Minimum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period	3 years	3 years
Traditional [Member] | Maximum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period	9 years	9 years
Vintage [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Maximum future funding commitments		$ 14
Fair Value	$ 18	$ 21
Vintage [Member] | Minimum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period	1 year	1 year
Vintage [Member] | Maximum [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Liquidating Investment, Remaining Period	2 years	2 years
Investment Funds [Member]
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair Value	$ 264	$ 251

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule Of Significant Unobservable Inputs Used In Level 3 Liability Valuations) (Detail) - USD ($) $ in Millions

9 Months Ended

Sep. 30, 2017

Jun. 30, 2017

[2]

Dec. 31, 2016

Sep. 30, 2016

[4],[5]

Jun. 30, 2016

[4]

Dec. 31, 2015

[5]

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]

Fair Value Measurements, Valuation Techniques

[1]

Actuarial model

Minimum [Member]

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]

Long-Duration Contracts, Assumptions by Product and Guarantee, Lapse Rate

[1]

3.00%

Significant Unobservable Inputs Annuitization Rate

[1]

0.00%

Maximum [Member]

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]

Long-Duration Contracts, Assumptions by Product and Guarantee, Lapse Rate

[1]

34.00%

Significant Unobservable Inputs Annuitization Rate

[1]

78.00%

Guaranteed Minimum Income Benefit [Member]

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]

Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value

$ 303

[2],[3]

$ 357

$ 559

[3]

$ 883

$ 971

$ 609

Guaranteed Minimum Income Benefit [Member] | Fair Value, Inputs, Level 3 [Member]

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]

Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value

$ 303

559

Guaranteed Minimum Income Benefit [Member] | Fair Value, Inputs, Level 3 [Member] | Fair Value, Measurements, Recurring [Member]

Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]

Fair Value, Measurement with Unobservable Inputs Reconciliations, Recurring Basis, Liability Value

$ 559

[1]

Discussion of the most significant inputs used in the fair value measurement of GLB and the sensitivity of those assumptions is included within Note 4 a) Guaranteed living benefits.

[2]

Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $635 million at September 30, 2017, and $684 million at June 30, 2017, which includes a fair value derivative adjustment of $303 million and $357 million, respectively.

[3]

Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $635 million at September 30, 2017, and $853 million at December 31, 2016, which includes a fair value derivative adjustment of $303 million and $559 million, respectively

[4]

Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $1.2 billion at September 30, 2016, and $1.3 billion at June 30, 2016, which includes a fair value derivative adjustment of $883 million and $971 million, respectively.

[5]

Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $1.2 billion at September 30, 2016, and $888 million at December 31, 2015, which includes a fair value derivative adjustment of $883 million and $609 million, respectively.

Fair Value Measurements (Assets

Fair Value Measurements (Assets Measured At Fair Value 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
Equity Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance- Beginning of Period, Assets	$ 39	$ 37	$ 41	$ 16
Transfers Into Level 3, Asset	0	0	0	0
Transfers out of Level 3, Assets	0	0	0	0
Asset, Net realized Gain (Loss) Included in Other Comprehensive Income (Loss)	0	3	1	2
Net Realized Gains/ (Losses), Assets	1	0	1	1
Purchases, Assets	17	0	23	23	[1],[2]
Sales, Assets	(5)	(3)	(14)	(5)
Settlements, Assets	0	0	0	0
Balance-End of Period, Assets	52	37	52	37
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0	0	0	0
Short-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance- Beginning of Period, Assets	7	50	25	0
Transfers Into Level 3, Asset	0	0	0	0
Transfers out of Level 3, Assets	0	0	0	0
Asset, Net realized Gain (Loss) Included in Other Comprehensive Income (Loss)	0	0	0	0
Net Realized Gains/ (Losses), Assets	0	0	0	0
Purchases, Assets	1	12	15	62	[1],[2]
Sales, Assets	0	0	0	0
Settlements, Assets	(8)	0	(40)	0
Balance-End of Period, Assets	0	62	0	62
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)		0	0	0
Other Long-term Investments [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance- Beginning of Period, Assets	243	216	225	212
Transfers Into Level 3, Asset	0	0	0	0
Transfers out of Level 3, Assets	0	0	0	0
Asset, Net realized Gain (Loss) Included in Other Comprehensive Income (Loss)	0	4	3	4
Net Realized Gains/ (Losses), Assets	0	0	0	0
Purchases, Assets	15	8	39	22	[1],[2]
Sales, Assets	0	0	0	0
Settlements, Assets	(6)	(5)	(15)	(15)
Balance-End of Period, Assets	252	223	252	223
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0	0	0	0
Available-for-sale Securities [Member] | Foreign Government Debt Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance- Beginning of Period, Assets	85	87	74	57
Transfers Into Level 3, Asset	0	0	0	9
Transfers out of Level 3, Assets	(3)	0	(3)	(2)
Asset, Net realized Gain (Loss) Included in Other Comprehensive Income (Loss)	1	(1)	3	8
Net Realized Gains/ (Losses), Assets	0	0	1	(6)
Purchases, Assets	24	20	57	52	[1],[2]
Sales, Assets	(14)	(2)	(36)	(10)
Settlements, Assets	(3)	(1)	(6)	(5)
Balance-End of Period, Assets	90	103	90	103
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0	0	0	(5)
Available-for-sale Securities [Member] | Corporate [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance- Beginning of Period, Assets	747	281	681	174
Transfers Into Level 3, Asset	111	0	168	18
Transfers out of Level 3, Assets	(26)	0	(93)	0
Asset, Net realized Gain (Loss) Included in Other Comprehensive Income (Loss)	(1)	6	(9)	17
Net Realized Gains/ (Losses), Assets	0	(4)	(1)	(12)
Purchases, Assets	169	348	390	472	[1],[2]
Sales, Assets	(24)	(18)	(79)	(48)
Settlements, Assets	(57)	(7)	(138)	(15)
Balance-End of Period, Assets	919	606	919	606
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0	(4)	0	(11)
Available-for-sale Securities [Member] | Collateralized Mortgage Backed Securities [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance- Beginning of Period, Assets	45	49	45	53
Transfers Into Level 3, Asset	0	0	0	0
Transfers out of Level 3, Assets	0	0	0	0
Asset, Net realized Gain (Loss) Included in Other Comprehensive Income (Loss)	0	0	0	0
Net Realized Gains/ (Losses), Assets	0	0	0	0
Purchases, Assets	7	0	8	1	[1],[2]
Sales, Assets	0	(3)	(1)	(8)
Settlements, Assets	(8)	0	(8)	0
Balance-End of Period, Assets	44	46	44	46
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	$ 0	$ 0	$ 0	$ 0
[1]	Includes acquired invested assets as a result of the Chubb Corp acquisition.
[2]	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $1.2 billion at September 30, 2016, and $888 million at December 31, 2015, which includes a fair value derivative adjustment of $883 million and $609 million, respectively.

Fair value measurements Fair 52

Fair value measurements Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation (Details) - USD ($) $ in Millions	3 Months Ended				9 Months Ended
	Sep. 30, 2017		Sep. 30, 2016		Sep. 30, 2017		Sep. 30, 2016		Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Guaranteed Minimum Income Benefit [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Reported liabilities	$ 635		$ 1,200		$ 635		$ 1,200		$ 684	$ 853	$ 1,300	$ 888
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance - Beginning of Period, Liabilities	357	[1]	971	[2]	559	[3]	609	[4]
Transfers into level 3, liability	0		0		9		0
Transfers out of Level 3, Liabilities	0		0		0		0
Change in Net Unrealized Gains (Losses) included in OCI, Liabilities	0		0		0		0
Net Realized Gains/Losses, Liabilities	(54)		(88)		(265)		274
Purchases, Liabilities	0		0		0		0	[4],[5]
Sales, Liabilities	0		0		0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements	0		0		0		0
Balance - End of Period, Liabilities	303	[1],[3]	883	[2],[4]	303	[1],[3]	883	[2],[4]
Fair Value, Liabilities Measured on Recurring Basis, Change in Unrealized Gain (Loss)	(54)		(88)		(265)		274
Other Derivative Instruments Fair Value [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance - Beginning of Period, Liabilities	2		10		13		6
Transfers into level 3, liability	0		0		0		0
Transfers out of Level 3, Liabilities	0		0		(9)		0
Change in Net Unrealized Gains (Losses) included in OCI, Liabilities	0		0		0		0
Net Realized Gains/Losses, Liabilities	0		0		(2)		2
Purchases, Liabilities	0		0		0		2	[4],[5]
Sales, Liabilities	0		0		0		0
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Settlements	0		(2)		0		(2)
Balance - End of Period, Liabilities	2		8		2		8
Fair Value, Liabilities Measured on Recurring Basis, Change in Unrealized Gain (Loss)	$ 0		$ 0		$ (2)		$ 2
[1]	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $635 million at September 30, 2017, and $684 million at June 30, 2017, which includes a fair value derivative adjustment of $303 million and $357 million, respectively.
[2]	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $1.2 billion at September 30, 2016, and $1.3 billion at June 30, 2016, which includes a fair value derivative adjustment of $883 million and $971 million, respectively.
[3]	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $635 million at September 30, 2017, and $853 million at December 31, 2016, which includes a fair value derivative adjustment of $303 million and $559 million, respectively
[4]	Our GLB reinsurance product meets the definition of a derivative instrument for accounting purposes and is accordingly carried at fair value. Excluded from the table above is the portion of the GLB derivative liability classified as Future policy benefits in the Consolidated balance sheets. The liability for GLB reinsurance was $1.2 billion at September 30, 2016, and $888 million at December 31, 2015, which includes a fair value derivative adjustment of $883 million and $609 million, respectively.
[5]	Includes acquired invested assets as a result of the Chubb Corp acquisition.

Fair Value Measurements (Carryi

Fair Value Measurements (Carrying Values And Fair Values Of Financial Instruments Not Measured At Fair Value) (Detail) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	$ 10,365	$ 10,670
Held-to-maturity Securities	10,160	10,644
Repurchase agreements	1,408	1,403
Short-term debt	1,020	500
Long-term debt	11,559	12,610
Trust preferred securities	308	308
Total liabilities	117,107	111,511
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	563	555
Repurchase agreements	0	0
Short-term Debt, Fair Value	0	0
Long-term Debt, Fair Value	0	0
Trust preferred securities	0	0
Total liabilities	0	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	9,791	10,102
Repurchase agreements	1,408	1,403
Short-term Debt, Fair Value	1,025	503
Long-term Debt, Fair Value	12,273	12,998
Trust preferred securities	467	456
Total liabilities	15,173	15,360
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	11	13
Repurchase agreements	0	0
Short-term Debt, Fair Value	0	0
Long-term Debt, Fair Value	0	0
Trust preferred securities	0	0
Total liabilities	0	0
U.S. Treasury And Agency [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	563	555
U.S. Treasury And Agency [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	58	106
U.S. Treasury And Agency [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	0	0
Foreign [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	0	0
Foreign [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	644	667
Foreign [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	0	0
Corporate [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	0	0
Corporate [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	2,578	2,782
Corporate [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	11	13
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	0	0
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	1,258	1,428
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	0	0
States, Municipalities, And Political Subdivisions [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	0	0
States, Municipalities, And Political Subdivisions [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	5,253	5,119
States, Municipalities, And Political Subdivisions [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	0	0
Estimate of Fair Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	10,365	10,670
Repurchase agreements	1,408	1,403
Short-term Debt, Fair Value	1,025	503
Long-term Debt, Fair Value	12,273	12,998
Trust preferred securities	467	456
Total liabilities	15,173	15,360
Estimate of Fair Value Measurement [Member] | U.S. Treasury And Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	621	661
Estimate of Fair Value Measurement [Member] | Foreign [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	644	667
Estimate of Fair Value Measurement [Member] | Corporate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	2,589	2,795
Estimate of Fair Value Measurement [Member] | Collateralized Mortgage Backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	1,258	1,428
Estimate of Fair Value Measurement [Member] | States, Municipalities, And Political Subdivisions [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Fair Value	5,253	5,119
Reported Value Measurement [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities	10,160	10,644
Repurchase agreements	1,408	1,403
Short-term debt	1,020	500
Long-term debt	11,559	12,610
Trust preferred securities	308	308
Total liabilities	14,295	14,821
Reported Value Measurement [Member] | U.S. Treasury And Agency [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities	611	655
Reported Value Measurement [Member] | Foreign [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities	616	640
Reported Value Measurement [Member] | Corporate [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities	2,531	2,771
Reported Value Measurement [Member] | Collateralized Mortgage Backed Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities	1,223	1,393
Reported Value Measurement [Member] | States, Municipalities, And Political Subdivisions [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities	$ 5,179	$ 5,185

Unpaid losses and loss expens54

Unpaid losses and loss expenses Unpaid losses and loss expenses (RF Details) - USD ($) $ in Millions		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016	Jan. 14, 2016
Unpaid Losses and Loss Expenses [Roll Forward]
Gross unpaid losses and loss expenses, beginning of year		$ 60,540	$ 37,303
Reinsurance Recoverable on unpaid losses, beginning of year	[1]	(12,708)	(10,741)
Net unpaid loss, beginning of period		47,832	26,562
Acquisition of subsidiaries				$ 0	$ 21,402
Total, Beginning of year		47,832	47,964
Current Year Claims and Claims Adjustment Expense		14,963	13,169
PPD (Favorable) / Adverse	[2]	(781)	(972)
Total, Incurred		14,182	12,197
Net loss and loss expenses paid, Current Year		3,937	3,865
Net losses and loss expenses Paid, Prior Years		8,389	7,470
Total, Paid		12,326	11,335
Liability For Unpaid Claims And Claims Adjustment Expense Foreign Currency Revaluation And Other		596	(155)
Net unpaid Loss, end of period		50,283	48,671
Reinsurance Recoverables on unpaid losses, end of year	[1]	13,870	12,676
Gross unpaid losses and loss expenses, end of year		64,153	61,347
prior period development, net adjustments		$ 110	$ 75
[1]	Net of provision for uncollectible reinsurance
[2]	Relates to prior period loss reserve development only and excludes prior period development related to reinstatement premiums, expense adjustments, and earned premiums totaling $110 million and $75 million for the nine months ended September 30, 2017 and 2016, respectively.

Unpaid losses and loss expens55

Unpaid losses and loss expenses Unpaid losses and loss expenses (narrative details) (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse	[1]			$ (781)	$ (972)
prior period development, net adjustments				110	75
North America Commercial P&C Insurance [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		$ (236)	$ (187)	(546)	(533)
North America Commercial P&C Insurance [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		(242)	(167)	(431)	(473)
North America Commercial P&C Insurance [Member] | Short Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		6		(115)	(60)
North America Commercial P&C Insurance [Member] | North America Workers' Compensation [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse				(99)	(134)
North America Commercial P&C Insurance [Member] | Multi-Line [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
prior period development, net adjustments		26
North America Commercial P&C Insurance [Member] | Accident Year 2016 [Member] | North America Workers' Compensation [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse				(37)
North America Commercial P&C Insurance [Member] | Accident Year 2013 and prior [Member] | North America Workers' Compensation [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		(44)		(62)
North America Commercial P&C Insurance [Member] | Accident years 2008 - 2013 [Member] | Commercial Multi-peril and General Liability [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse				(27)
North America Commercial P&C Insurance [Member] | Accident years 2014 and 2016 [Member] | Property [Member] | Short Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse				(43)
North America Commercial P&C Insurance [Member] | Accident Year 2010 and Prior [Member] | Commercial Excess and Umbrella [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse			(127)		(272)
North America Commercial P&C Insurance [Member] | Accident year 2012 and 2013 [Member] | Professional Liability Insurance [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse				(30)
North America Commercial P&C Insurance [Member] | Accident year 2012 and 2013 [Member] | Multi-Line [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		(28)		(28)
North America Commercial P&C Insurance [Member] | Accident year 2015 and 2016 [Member] | Accident and Health Insurance Product Line [Member] | Short Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse				(19)
North America Commercial P&C Insurance [Member] | Accident year 2011 and prior [Member] | Commercial Excess and Umbrella [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		(140)		(213)
North America Commercial P&C Insurance [Member] | Accident Year 2015 [Member] | North America Workers' Compensation [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse					(40)
North America Commercial P&C Insurance [Member] | Accident Year 2015 [Member] | Credit Related Business [Member] | Short Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse				(45)
North America Commercial P&C Insurance [Member] | Accident year 2007 - 2014 [Member] | Primary Casualty GL [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse					(20)
North America Commercial P&C Insurance [Member] | Accident years 2012 and prior [Member] | North America Workers' Compensation [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse					(91)
North America Commercial P&C Insurance [Member] | Accident years 2012 and prior [Member] | Professional Liability Insurance [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse					(69)
North America Commercial P&C Insurance [Member] | Accident year 2014 and 2015 [Member] | Property [Member] | Short Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse			(20)		(46)
North America Personal P&C Insurance [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		32	38	66	20
North America Personal P&C Insurance [Member] | Personal Homeowner [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse			28	105
North America Personal P&C Insurance [Member] | Accident Year 2016 [Member] | Personal Homeowner [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		98
North America Personal P&C Insurance [Member] | Accident Year 2014 [Member] | Personal Excess [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		(58)		(58)
North America Agricultural Insurance [Member] | Short Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		(4)	(11)
North America Agricultural Insurance [Member] | Commercial Multi-peril and General Liability [Member] | Short Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse				(83)	(52)
Overseas General Insurance [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		(108)	(223)	(184)	(338)
Overseas General Insurance [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		(109)	(234)	(78)	(235)
Overseas General Insurance [Member] | Short Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse			11	(106)	(103)
Overseas General Insurance [Member] | Casualty [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		(40)		(9)
Overseas General Insurance [Member] | Casualty and Financial [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse			(167)		(167)
Overseas General Insurance [Member] | Individual Legacy Liability [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse			(25)
Overseas General Insurance [Member] | Financial [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		(34)		(34)
Overseas General Insurance [Member] | Accident Year 2013 and prior [Member] | Casualty [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		(69)
Overseas General Insurance [Member] | Accident Year 2013 and prior [Member] | Financial [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		(124)
Overseas General Insurance [Member] | Accident year 2013 to 2015 [Member] | Property and Inland Marine [Member] | Short Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse				(37)
Overseas General Insurance [Member] | Accident year 2013 to 2015 [Member] | Casualty and Financial [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse			94		94
Overseas General Insurance [Member] | Accident years 2014 - 2016 [Member] | Accident and Health Insurance Product Line [Member] | Short Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse				(20)
Overseas General Insurance [Member] | Accident years 2014 - 2016 [Member] | Casualty [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		29
Overseas General Insurance [Member] | Accident years 2014 - 2016 [Member] | Energy and Technical Risk Property [Member] | Short Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse				(43)
Overseas General Insurance [Member] | Accident years 2014 - 2016 [Member] | Financial [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		90
Overseas General Insurance [Member] | Accident years 2012 and prior [Member] | Casualty and Financial [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse			(261)		(261)
Overseas General Insurance [Member] | Accident years 2012 and prior [Member] | Aviation [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse			(28)
Overseas General Insurance [Member] | Accident years 2016 and prior [Member] | Casualty and Financial [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse				32
Overseas General Insurance [Member] | Accident year 2012 to 2014 [Member] | Property [Member] | Short Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse					(66)
Overseas General Insurance [Member] | Accident year 2010 to 2014 [Member] | Energy and Technical Risk Property [Member] | Short Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse					(35)
Global Reinsurance [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		(41)	(28)	(64)	(78)
Global Reinsurance [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse				(67)
Global Reinsurance [Member] | Auto Liability Excess Lines [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse				10
Global Reinsurance [Member] | Accident Year 2013 and prior [Member] | Professional Liability Insurance [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		(29)		(66)
Global Reinsurance [Member] | Accident year 2011 and prior [Member] | Professional Liability Insurance [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse			(24)		(30)
Global Reinsurance [Member] | Accident year 2011 and prior [Member] | Casualty [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse					(41)
Global Reinsurance [Member] | Accident Year 2015 [Member] | Auto Liability Excess Lines [Member] | Long Tail [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse				9
Corporate Segment [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		87	62	140	84
Corporate Segment [Member] | Discontinued Operations [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		9	10	28	$ 27
Corporate Segment [Member] | non-A&E run-off [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse				$ 35
Corporate Segment [Member] | Asbestos & Environmental [Member]
Liability for Claims and Claims Adjustment Expense [Line Items]
PPD (Favorable) / Adverse		$ 77	$ 52
[1]	Relates to prior period loss reserve development only and excludes prior period development related to reinstatement premiums, expense adjustments, and earned premiums totaling $110 million and $75 million for the nine months ended September 30, 2017 and 2016, respectively.

Commitments, Contingencies, A56

Commitments, Contingencies, And Guarantees (Narrative) (Detail) - USD ($) $ in Millions	Oct. 31, 2017	Sep. 30, 2017	Dec. 31, 2016
Financial Instruments Owned and Pledged as Collateral [Line Items]
Purchase Commitment, Remaining Minimum Amount Committed		$ 932
Derivative liability subject to a master netting agreement		41	$ 10
Unrecognized tax benefits		14
Repurchase agreements		1,408	$ 1,403
Funding commitments relating to limited partnerships and partially-owned investment companies		1,700
Carrying value of limited partnerships and partially-owned investment companies included in other investments		$ 3,400
Subsequent Event [Member]
Financial Instruments Owned and Pledged as Collateral [Line Items]
Funding commitments relating to limited partnerships and partially-owned investment companies	$ 2,500

Commitments, Contingencies, A57

Commitments, Contingencies, And Guarantees (Balance Sheet Locations, Fair Values In Asset Or (Liability) Position, And Notional Values/Payment Provisions Of Derivative Instruments) (Detail) - USD ($) $ in Millions		Sep. 30, 2017	Dec. 31, 2016
Foreign currency forward contracts
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision		$ 2,035	$ 2,220
Cross Currency Swap [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Liability		0	0
Fair Value, Asset		0	0
Notional Value/Payment Provision		45	95
Options/Futures contracts on notes and bonds
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision		1,437	2,344
Convertibles and Bonds with Warrants Attached [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision		4	7	[1]
Investment And Embedded Derivative Instruments [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Asset		15	33
Notional Value/Payment Provision		3,521	4,666
Single-Stock Future [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	[2]	1,455	1,316
Other Derivatives [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision		259	214
Other Derivative Instruments [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision		1,714	1,530
Guaranteed Living Benefits [Member]
Derivatives, Fair Value [Line Items]
Notional Value/Payment Provision	[3]	1,138	1,264
Other Assets [Member] | Foreign currency forward contracts
Derivatives, Fair Value [Line Items]
Fair Value, Asset		8	25
Other Assets [Member] | Options/Futures contracts on notes and bonds
Derivatives, Fair Value [Line Items]
Fair Value, Asset		7	6
Other Assets [Member] | Single-Stock Future [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Asset	[2]	0	1
Other Assets [Member] | Other Derivatives [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Asset		0	2
Other Assets [Member] | Other Derivative Instruments [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Asset		0	3
Other Assets [Member] | Guaranteed Living Benefits [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Asset	[3]	0	0
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Foreign currency forward contracts
Derivatives, Fair Value [Line Items]
Fair Value, Liability		(31)	(50)
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Options/Futures contracts on notes and bonds
Derivatives, Fair Value [Line Items]
Fair Value, Liability		(6)	(4)
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Convertibles and Bonds with Warrants Attached [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Liability		0	0	[1]
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Investment And Embedded Derivative Instruments [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Liability		(37)	(54)
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Single-Stock Future [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Liability	[2]	(25)	0
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Other Derivatives [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Liability		(2)	(13)
Accounts Payable, Accrued Expenses, And Other Liabilities [Member] | Other Derivative Instruments [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Liability		(27)	(13)
Fixed Maturities Available For Sale [Member] | Convertibles and Bonds with Warrants Attached [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Asset		0	2	[1]
Accounts Payable Future Policy Benefits [Member] | Guaranteed Living Benefits [Member]
Derivatives, Fair Value [Line Items]
Fair Value, Liability	[3]	$ (635)	$ (853)
[1]	Includes fair value of embedded derivatives.
[2]	Related to GMDB and GLB blocks of business.
[3]	Includes both future policy benefits reserves and fair value derivative adjustment. Note that the payment provision related to GLB is the net amount at risk. The concept of a notional value does not apply to the GLB reinsurance contracts.

Commitments, contingencies, a58

Commitments, contingencies, and guarantees Commitments, Contingencies, And Guarantees (Transactions accounted for as secured borrowings) (Details) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending collateral	$ 1,757	$ 1,092
Securities lending payable	1,757	1,093
Overnight and Continuous [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Secured Borrowings, Gross, Difference, Amount	0	(1)	[1]
Cash and Cash Equivalents [Member] | Overnight and Continuous [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending collateral	1,109	423
U.S. Treasury And Agency [Member] | Overnight and Continuous [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending collateral	38	54
Foreign Government Debt [Member] | Overnight and Continuous [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending collateral	491	578
Corporate [Member] | Overnight and Continuous [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending collateral	0	37
Collateralized Mortgage Backed Securities [Member] | Overnight and Continuous [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending collateral	46	0
Equity Securities [Member] | Overnight and Continuous [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Securities lending collateral	$ 73	$ 0
[1]	(1) The carrying value of the securities lending collateral held is $1 million lower than the securities lending payable at December 31, 2016 due to accrued interest recorded in the securities lending payable.

Commitments, contingencies, a59

Commitments, contingencies, and guarantees Commitments, Contingencies, And Guarantees (Collateral pledged under repurchase agreements) (Details) - USD ($) $ in Millions		Sep. 30, 2017	Dec. 31, 2016
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Assets pledged under repurchase agreements		$ 1,441	$ 1,461
Repurchase agreements		1,408	1,403
Cash and Cash Equivalents [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Assets pledged under repurchase agreements		0	1
U.S. Treasury And Agency [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Assets pledged under repurchase agreements		240	240
Collateralized Mortgage Backed Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Assets pledged under repurchase agreements		1,201	1,220
Repurchase Agreements [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Secured Borrowings, Gross, Difference, Amount	[1]	33	58
Maturity Less than 30 Days [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Assets pledged under repurchase agreements		574	569
Maturity Less than 30 Days [Member] | Cash and Cash Equivalents [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Assets pledged under repurchase agreements		0	0
Maturity Less than 30 Days [Member] | U.S. Treasury And Agency [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Assets pledged under repurchase agreements		231	230
Maturity Less than 30 Days [Member] | Collateralized Mortgage Backed Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Assets pledged under repurchase agreements		343	339
Maturity Greater than 90 Days [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Assets pledged under repurchase agreements		867	892
Maturity Greater than 90 Days [Member] | Cash and Cash Equivalents [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Assets pledged under repurchase agreements		0	1
Maturity Greater than 90 Days [Member] | U.S. Treasury And Agency [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Assets pledged under repurchase agreements		9	10
Maturity Greater than 90 Days [Member] | Collateralized Mortgage Backed Securities [Member]
Transfer of Certain Financial Assets Accounted for as Secured Borrowings [Line Items]
Assets pledged under repurchase agreements		$ 858	$ 881
[1]	(1) Per the repurchase agreements, the amount of collateral posted is required to exceed the amount of gross liability.

Commitments, Contingencies, A60

Commitments, Contingencies, And Guarantees (Net Realized Gains (Losses) Of Derivative Instrument Activity In Consolidated Statement Of Operations) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Gain Loss on Derivative	$ (22)	$ 48	$ 68	$ (442)
Foreign currency forward contracts
Derivative Instruments, Gain (Loss) [Line Items]
Gain Loss on Derivative	(7)	(10)	0	(30)
All Other Futures Contracts And Options [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain Loss on Derivative	(8)	8	(25)	(63)
Convertibles and Bonds with Warrants Attached [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain Loss on Derivative	1	3	1	8
Investment And Embedded Derivative Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain Loss on Derivative	(14)	1	(24)	(85)
Guaranteed Minimum Income Benefit [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain Loss on Derivative	54	89	265	(270)
Single-Stock Future [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain Loss on Derivative	(57)	(45)	(169)	(88)
Other Derivatives [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain Loss on Derivative	(5)	3	(4)	1
Guaranteed Living Benefit And Other Derivative Instruments [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Gain Loss on Derivative	$ (8)	$ 47	$ 92	$ (357)

Commitments, contingencies, a61

Commitments, contingencies, and guarantees Commitments, Contingencies, And Gaurentees (Letter of Credit Narrative) - USD ($) $ in Billions	Oct. 31, 2017	Oct. 25, 2017	Sep. 30, 2017
Line of Credit Facility [Line Items]
Other Investments Limited Partnerships And Partially Owned Investment Companies Funding Commitments			$ 1.7
Line of Credit Facility, Current Borrowing Capacity			$ 1.5
Subsequent Event [Member]
Line of Credit Facility [Line Items]
Other Investments Limited Partnerships And Partially Owned Investment Companies Funding Commitments	$ 2.5
Line of Credit Facility, Maximum Borrowing Capacity		$ 2
Line of Credit Facility, Current Borrowing Capacity		1
Line of Credit Facility, Capacity Available for Specific Purpose Other than for Trade Purchases		$ 1

Shareholders' equity Sharehol62

Shareholders' equity Shareholders' equity (Details) $ / shares in Units, $ in Billions	Sep. 30, 2017SFr / sharesshares	May 31, 2017$ / shares	Dec. 31, 2016SFr / sharesshares	Nov. 30, 2016USD ($)	May 31, 2016$ / shares	May 31, 2015$ / shares
Equity, Class of Treasury Stock [Line Items]
Common Shares, par value | SFr / shares	SFr 24.15		SFr 24.15
Common Shares in treasury, shares | shares	15,625,345		13,815,148
Common Stock, Dividend Rate Approved		$ 0.71			$ 0.69	$ 0.67
Annual dividend per share approved by shareholders		$ 2.84			$ 2.76	$ 2.68
Nov 2016 Stock Repurchase Plan [Member]
Equity, Class of Treasury Stock [Line Items]
Authorized amount of share repurchase program | $				$ 1

Shareholders' equity Dividends

Shareholders' equity Dividends declared (Details)	3 Months Ended				9 Months Ended
	Sep. 30, 2017$ / shares	Sep. 30, 2017SFr / shares	Sep. 30, 2016$ / shares	Sep. 30, 2016SFr / shares	Sep. 30, 2017$ / shares	Sep. 30, 2017SFr / shares	Sep. 30, 2016$ / shares	Sep. 30, 2016SFr / shares
Dividends Declared [Abstract]
Common Stock, Dividend Rate Declared | (per share)	$ 0.71	SFr 0.68	$ 0.69	SFr 0.67	$ 2.11	SFr 2.06	$ 2.05	SFr 2.01

Shareholders' equity Share Repu

Shareholders' equity Share Repurchases (Details) - Nov 2016 Stock Repurchase Plan [Member] - USD ($) $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	Oct. 31, 2017	Sep. 30, 2017	Sep. 30, 2017
Class of Stock [Line Items]
Treasury Stock, Shares, Acquired		1,615,383	5,033,013
Treasury Stock, Value, Acquired, Cost Method		$ 232	$ 707
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 293	$ 293
Subsequent Event [Member]
Class of Stock [Line Items]
Treasury Stock, Shares, Acquired	25,000
Treasury Stock, Value, Acquired, Cost Method	$ 4
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 289

Share-Based Compensation (Detai

Share-Based Compensation (Detail) - $ / shares	Feb. 23, 2017	Sep. 30, 2017
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period in years		3 years
Award term period in years		10 years
Stock options granted	2,065,620
Weighted-average grant date fair value for stock options granted	$ 22.97
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period in years		4 years
Restricted stock awards granted to employees and officers of the company	1,105,118
Grant date fair value of awards except for options granted to employees and officers of the company	$ 139.01
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units awarded to employees and officers of the company	326,272
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period in years		4 years
Restricted stock awards granted to employees and officers of the company	202,251

Postretirement benefits Compone

Postretirement benefits Components of net periodic benefit costs (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Pension Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	$ 21	$ 26	$ 61	$ 72
Interest cost	33	34	99	104
Expected return on plan assets	(58)	(52)	(173)	(151)
Amortization of net actuarial loss	1	0	2	2
Amortization of prior service cost	0		0
Curtailments	0	(4)	(8)	(4)
Settlements		(1)		(1)
Net periodic (benefit) cost	(3)	3	(19)	22
Pension Plan [Member] | UNITED STATES
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	15	20	47	57
Interest cost	27	26	79	80
Expected return on plan assets	(47)	(42)	(142)	(121)
Amortization of net actuarial loss	0	0	0	0
Amortization of prior service cost	0		0
Curtailments	0	(4)	0	(4)
Settlements		(1)		(1)
Net periodic (benefit) cost	(5)	(1)	(16)	11
Pension Plan [Member] | Non-US [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	6	6	14	15
Interest cost	6	8	20	24
Expected return on plan assets	(11)	(10)	(31)	(30)
Amortization of net actuarial loss	1	0	2	2
Amortization of prior service cost	0		0
Curtailments	0	0	(8)	0
Settlements		0		0
Net periodic (benefit) cost	2	4	(3)	11
Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	0	4	2	9
Interest cost	2	4	3	13
Expected return on plan assets	(2)	(3)	(4)	(7)
Amortization of net actuarial loss	0	0	0	0
Amortization of prior service cost	(22)		(68)
Curtailments	(32)	0	(32)	0
Settlements		0		0
Net periodic (benefit) cost	(54)	5	(99)	15
Other Postretirement Benefits Plan [Member] | UNITED STATES
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	0	4	1	8
Interest cost	1	4	2	13
Expected return on plan assets	(2)	(3)	(4)	(7)
Amortization of net actuarial loss	0	0	0	0
Amortization of prior service cost	(22)		(68)
Curtailments	(32)	0	(32)	0
Settlements		0		0
Net periodic (benefit) cost	(55)	5	(101)	14
Other Postretirement Benefits Plan [Member] | Non-US [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Service cost	0	0	1	1
Interest cost	1	0	1	0
Expected return on plan assets	0	0	0	0
Amortization of net actuarial loss	0	0	0	0
Amortization of prior service cost	0		0
Curtailments	0	0	0	0
Settlements		0		0
Net periodic (benefit) cost	$ 1	$ 0	$ 2	$ 1

Segment information Segment Inf

Segment information Segment Information (narrative Detail (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Derivative, (Gain) Loss on Derivative, Net	$ 22	$ (48)	$ (68)	$ 442
Net investment income	813	739	2,328	2,121
North America Agricultural Insurance [Member]
Segment Reporting Information [Line Items]
Segment Income Loss Including Gains Losses On Crop Derivatives	86
Derivative, (Gain) Loss on Derivative, Net	5
Net investment income	6	5	18	15
Segment Life [Member]
Segment Reporting Information [Line Items]
Net investment income	78	$ 71	$ 230	$ 207
Management Underwriting Income (Loss)	70
Gains Losses On Fair Value Changes In Separate Account Assets	$ 24

Segment Information (Operations

Segment Information (Operations By Segment) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Segment Reporting Information [Line Items]
Net premiums written	$ 7,902	$ 7,573	$ 22,193	$ 21,207
Net premiums earned	7,807	7,688	21,816	21,690
Losses and loss expenses	6,247	4,269	14,182	12,197
Policy benefits	169	155	500	427
Policy acquisition costs	1,488	1,514	4,334	4,487
Administrative expenses	714	772	2,096	2,373
Underwriting income (loss)	(811)	978	704	2,206
Net investment income	813	739	2,328	2,121
Other (income) expense	(118)	(91)	(333)	(92)
Amortization of purchased intangibles	65	4	194	16
Segment Income (loss)	55	1,804	3,171	4,403
Net realized gains (losses) including OTTI	(10)	100	84	(510)
Interest expense	150	152	451	451
Chubb integration expenses	50	115	233	361
Income tax benefit	(85)	277	243	556
Net income (loss)	(70)	1,360	2,328	2,525
North America Commercial P&C Insurance [Member]
Segment Reporting Information [Line Items]
Net premiums written	3,089	3,110	9,035	8,657
Net premiums earned	3,016	3,086	9,156	9,130
Losses and loss expenses	2,580	1,863	6,376	5,581
Policy benefits	0		0	0
Policy acquisition costs	469	522	1,420	1,549
Administrative expenses	256	275	728	840
Underwriting income (loss)	(289)	426	632	1,160
Net investment income	497	477	1,465	1,371
Other (income) expense	(4)	3	(4)	(6)
Amortization of purchased intangibles	0	0	0	0
Segment Income (loss)	212	900	2,101	2,537
North America Personal P&C Insurance [Member]
Segment Reporting Information [Line Items]
Net premiums written	1,194	1,011	3,433	3,113
Net premiums earned	1,117	1,081	3,296	3,245
Losses and loss expenses	1,062	594	2,378	1,916
Policy benefits	0		0	0
Policy acquisition costs	226	229	673	747
Administrative expenses	61	89	192	275
Underwriting income (loss)	(232)	169	53	307
Net investment income	57	53	168	155
Other (income) expense	1	2	3	6
Amortization of purchased intangibles	4	4	12	16
Segment Income (loss)	(180)	216	206	440
North America Agricultural Insurance [Member]
Segment Reporting Information [Line Items]
Net premiums written	926	849	1,390	1,288
Net premiums earned	898	819	1,256	1,169
Losses and loss expenses	759	683	976	937
Policy benefits	0		0	0
Policy acquisition costs	49	48	75	77
Administrative expenses	(1)	1	(4)	(1)
Underwriting income (loss)	91	87	209	156
Net investment income	6	5	18	15
Other (income) expense	0	0	1	0
Amortization of purchased intangibles	8	7	22	22
Segment Income (loss)	89	85	204	149
Overseas General Insurance [Member]
Segment Reporting Information [Line Items]
Net premiums written	1,963	1,940	6,169	6,012
Net premiums earned	2,064	2,034	6,018	6,082
Losses and loss expenses	1,281	843	3,316	2,953
Policy benefits	0		0	0
Policy acquisition costs	569	546	1,653	1,586
Administrative expenses	246	261	734	801
Underwriting income (loss)	(32)	384	315	742
Net investment income	164	152	460	445
Other (income) expense	(10)	(6)	(14)	(16)
Amortization of purchased intangibles	11	12	33	36
Segment Income (loss)	131	530	756	1,167
Global Reinsurance [Member]
Segment Reporting Information [Line Items]
Net premiums written	191	131	580	562
Net premiums earned	185	156	542	543
Losses and loss expenses	295	49	435	225
Policy benefits	0		0	0
Policy acquisition costs	43	42	137	142
Administrative expenses	11	12	33	40
Underwriting income (loss)	(164)	53	(63)	136
Net investment income	80	67	207	199
Other (income) expense	(3)	0	(2)	(3)
Amortization of purchased intangibles	0	0	0	0
Segment Income (loss)	(81)	120	146	338
Life Insurance [Member]
Segment Reporting Information [Line Items]
Net premiums written	539	532	1,586	1,575
Net premiums earned	527	512	1,548	1,521
Losses and loss expenses	181	174	556	498
Policy benefits	169	155	500	427
Policy acquisition costs	132	127	376	386
Administrative expenses	77	77	226	226
Underwriting income (loss)	(32)	(21)	(110)	(16)
Net investment income	78	71	230	207
Other (income) expense	(19)	(20)	(60)	(14)
Amortization of purchased intangibles	1	1	2	2
Segment Income (loss)	64	69	178	203
Corporate And Other [Member]
Segment Reporting Information [Line Items]
Net premiums written	0		0	0
Net premiums earned	0		0	0
Losses and loss expenses	89	63	145	87
Policy benefits	0		0	0
Policy acquisition costs	0	0	0	0
Administrative expenses	64	57	187	192
Underwriting income (loss)	(153)	(120)	(332)	(279)
Net investment income	(69)	(86)	(220)	(271)
Other (income) expense	(83)	(70)	(257)	(59)
Amortization of purchased intangibles	41	(20)	125	(60)
Segment Income (loss)	(180)	(116)	(420)	(431)
Net realized gains (losses) including OTTI	(10)	100	84	(510)
Interest expense	150	152	451	451
Chubb integration expenses	50	115	233	361
Income tax benefit	(85)	277	243	556
Net income (loss)	$ (305)	$ (560)	$ (1,263)	$ (2,309)

Earnings Per Share (Detail)

Earnings Per Share (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Earnings Per Share [Abstract]
Net income	$ (70)	$ 1,360	$ 2,328	$ 2,525
Weighted-average shares outstanding	466,370,784	468,021,093	467,658,334	460,631,794
Share-based compensation plans	3,820,673	3,375,269	3,961,572	3,439,017
Weighted-average shares outstanding and assumed conversions	466,370,784	471,396,362	471,619,906	464,070,811
Basic earnings per share (US$ per share)	$ (0.15)	$ 2.90	$ 4.98	$ 5.48
Diluted earnings per share (US$ per share)	$ (0.15)	$ 2.88	$ 4.94	$ 5.44
Potential anti-dilutive share conversions	2,045,829	1,306,710	1,673,777	1,635,337

Information provided in conne70

Information provided in connection with outstanding debt of subsidiaries Information provided in connection with outstanding debt of subsidiaries (Narrative) (Details)	Sep. 30, 2017
Debt Instrument [Line Items]
Equity Method Investment, Ownership Percentage	100.00%

Information Provided In Conne71

Information Provided In Connection With Outstanding Debt Of Subsidiaries (Condensed Consolidating Balance Sheet) (Detail) - USD ($) $ in Millions	Sep. 30, 2017		Dec. 31, 2016		Sep. 30, 2016		Dec. 31, 2015
Condensed Balance Sheet Statements, Captions [Line Items]
Investments	$ 102,424		$ 99,094
Cash	1,088	[1],[2]	985	[1],[3]	$ 870	[4]	$ 1,775	[4]
Insurance and reinsurance balances receivable	9,551		8,970
Reinsurance recoverable on losses and loss expenses	14,799		13,577
Reinsurance recoverable on policy benefits	193		182
Value of business acquired	339		355
Goodwill and other intangible assets	22,265		22,095
Investments in subsidiaries	0		0
Due from subsidiaries and affiliates, net	0		0
Other assets	16,919		14,528
Total assets	167,578		159,786
Unpaid losses and loss expenses	64,153		60,540		61,347		37,303
Unearned premiums	15,456		14,779
Future policy benefits	5,307		5,036
Due to subsidiaries and affiliates, net	0		0
Affiliated notional cash pooling programs	0		0
Repurchase agreements	1,408		1,403
Short-term debt	1,020		500
Long-term debt	11,559		12,610
Trust preferred securities	308		308
Other liabilities	17,896		16,335
Total liabilities	117,107		111,511
Total shareholders' equity	50,471		48,275		48,372
Total liabilities and shareholders’ equity	167,578		159,786
Chubb Limited (Parent Guarantor)
Condensed Balance Sheet Statements, Captions [Line Items]
Investments	0		27
Cash	1	[1],[2]	1	[1],[3]	6	[4]	1	[4]
Insurance and reinsurance balances receivable	0		0
Reinsurance recoverable on losses and loss expenses	0		0
Reinsurance recoverable on policy benefits	0		0
Value of business acquired	0		0
Goodwill and other intangible assets	0		0
Investments in subsidiaries	40,936		38,408
Due from subsidiaries and affiliates, net	9,913		10,482
Other assets	61		3
Total assets	50,911		48,921
Unpaid losses and loss expenses	0		0
Unearned premiums	0		0
Future policy benefits	0		0
Due to subsidiaries and affiliates, net	0		0
Affiliated notional cash pooling programs	85	[2]	363	[3]
Repurchase agreements	0		0
Short-term debt	0		0
Long-term debt	0		0
Trust preferred securities	0		0
Other liabilities	355		283
Total liabilities	440		646
Total shareholders' equity	50,471		48,275
Total liabilities and shareholders’ equity	50,911		48,921
Chubb INA Holdings Inc (Subsidiary Issuer)
Condensed Balance Sheet Statements, Captions [Line Items]
Investments	169		485
Cash	0	[1],[2]	1	[1],[3]	2	[4]	2	[4]
Insurance and reinsurance balances receivable	0		0
Reinsurance recoverable on losses and loss expenses	0		0
Reinsurance recoverable on policy benefits	0		0
Value of business acquired	0		0
Goodwill and other intangible assets	0		0
Investments in subsidiaries	50,926		49,509
Due from subsidiaries and affiliates, net	0		0
Other assets	276		436
Total assets	51,371		50,431
Unpaid losses and loss expenses	0		0
Unearned premiums	0		0
Future policy benefits	0		0
Due to subsidiaries and affiliates, net	9,697		10,209
Affiliated notional cash pooling programs	2	[2]	619	[3]
Repurchase agreements	0		0
Short-term debt	1,020		500
Long-term debt	11,548		12,599
Trust preferred securities	308		308
Other liabilities	1,685		1,582
Total liabilities	24,260		25,817
Total shareholders' equity	27,111		24,614
Total liabilities and shareholders’ equity	51,371		50,431
Other Chubb Limited Subsidiaries
Condensed Balance Sheet Statements, Captions [Line Items]
Investments	102,255		98,582
Cash	1,174	[1],[2]	1,965	[1],[3]	2,158	[4]	2,743	[4]
Insurance and reinsurance balances receivable	11,076		10,498
Reinsurance recoverable on losses and loss expenses	27,007		24,496
Reinsurance recoverable on policy benefits	1,232		1,153
Value of business acquired	339		355
Goodwill and other intangible assets	22,265		22,095
Investments in subsidiaries	0		0
Due from subsidiaries and affiliates, net	0		0
Other assets	20,699		18,442
Total assets	186,047		177,586
Unpaid losses and loss expenses	75,688		70,683
Unearned premiums	19,150		18,538
Future policy benefits	6,346		6,007
Due to subsidiaries and affiliates, net	216		273
Affiliated notional cash pooling programs	0	[2]	0	[3]
Repurchase agreements	1,408		1,403
Short-term debt	0		0
Long-term debt	11		11
Trust preferred securities	0		0
Other liabilities	18,477		17,368
Total liabilities	121,296		114,283
Total shareholders' equity	64,751		63,303
Total liabilities and shareholders’ equity	186,047		177,586
Consolidating Adjustments and Eliminations
Condensed Balance Sheet Statements, Captions [Line Items]
Investments	0		0
Cash	(87)	[1],[2]	(982)	[1],[3]	$ (1,296)	[4]	$ (971)	[4]
Insurance and reinsurance balances receivable	(1,525)		(1,528)
Reinsurance recoverable on losses and loss expenses	(12,208)		(10,919)
Reinsurance recoverable on policy benefits	(1,039)		(971)
Value of business acquired	0		0
Goodwill and other intangible assets	0		0
Investments in subsidiaries	(91,862)		(87,917)
Due from subsidiaries and affiliates, net	(9,913)		(10,482)
Other assets	(4,117)		(4,353)
Total assets	(120,751)		(117,152)
Unpaid losses and loss expenses	(11,535)		(10,143)
Unearned premiums	(3,694)		(3,759)
Future policy benefits	(1,039)		(971)
Due to subsidiaries and affiliates, net	(9,913)		(10,482)
Affiliated notional cash pooling programs	(87)	[2]	(982)	[3]
Repurchase agreements	0		0
Short-term debt	0		0
Long-term debt	0		0
Trust preferred securities	0		0
Other liabilities	(2,621)		(2,898)
Total liabilities	(28,889)		(29,235)
Total shareholders' equity	(91,862)		(87,917)
Total liabilities and shareholders’ equity	$ (120,751)		$ (117,152)
[1]	Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At September 30, 2017 and December 31, 2016, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[2]	Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At September 30, 2017, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[3]	Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At December 31, 2016, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[4]	Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At September 30, 2016 and December 31, 2015, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

Information Provided In Conne72

Information Provided In Connection With Outstanding Debt Of Subsidiaries (Condensed Consolidating Statement Of Operations) (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Condensed Statement of Income Captions [Line Items]
Net premiums written	$ 7,902	$ 7,573	$ 22,193	$ 21,207
Net premiums earned	7,807	7,688	21,816	21,690
Net investment income	813	739	2,328	2,121
Equity in earnings of subsidiaries	0	0	0	0
Net realized gains (losses) including OTTI	(10)	100	84	(510)
Losses and loss expenses	6,247	4,269	14,182	12,197
Policy benefits	169	155	500	427
Policy acquisition costs and administrative expenses	2,202	2,286	6,430	6,860
Interest (income) expense	150	152	451	451
Other (income) expense	(118)	(91)	(333)	(92)
Amortization of purchased intangibles	65	4	194	16
Chubb integration expenses	50	115	233	361
Income tax benefit	(85)	277	243	556
Net income (loss)	(70)	1,360	2,328	2,525
Comprehensive income (loss)	629	1,376	3,711	4,457
Consolidating Adjustments and Eliminations
Condensed Statement of Income Captions [Line Items]
Net premiums written	0	0	0	0
Net premiums earned	0	0	0	0
Net investment income	0	0	0	0
Equity in earnings of subsidiaries	(85)	(2,040)	(3,731)	(4,134)
Net realized gains (losses) including OTTI	0	0	0	0
Losses and loss expenses	0	0	0	0
Policy benefits	0	0	0	0
Policy acquisition costs and administrative expenses	0	0	0	0
Interest (income) expense	0	0	0	0
Other (income) expense	0	0	0	0
Amortization of purchased intangibles	0	0	0	0
Chubb integration expenses	0	0	0	0
Income tax benefit	0	0	0	0
Net income (loss)	(85)	(2,040)	(3,731)	(4,134)
Comprehensive income (loss)	(1,472)	(2,066)	(6,477)	(7,528)
Chubb Limited (Parent Guarantor)
Condensed Statement of Income Captions [Line Items]
Net premiums written	0	0	0	0
Net premiums earned	0	0	0	0
Net investment income	1	1	3	3
Equity in earnings of subsidiaries	(127)	1,292	2,153	2,331
Net realized gains (losses) including OTTI	0	0	(2)	(1)
Losses and loss expenses	0	0	0	0
Policy benefits	0	0	0	0
Policy acquisition costs and administrative expenses	20	15	56	48
Interest (income) expense	(84)	(93)	(252)	(266)
Other (income) expense	(5)	(7)	(7)	(20)
Amortization of purchased intangibles	0	0	0	0
Chubb integration expenses	7	12	13	29
Income tax benefit	6	6	16	17
Net income (loss)	(70)	1,360	2,328	2,525
Comprehensive income (loss)	629	1,376	3,711	4,457
Chubb INA Holdings Inc (Subsidiary Issuer)
Condensed Statement of Income Captions [Line Items]
Net premiums written	0	0	0	0
Net premiums earned	0	0	0	0
Net investment income	3	2	10	9
Equity in earnings of subsidiaries	212	748	1,578	1,803
Net realized gains (losses) including OTTI	(8)	(2)	(22)	(3)
Losses and loss expenses	0	0	0	0
Policy benefits	0	0	0	0
Policy acquisition costs and administrative expenses	16	12	28	144
Interest (income) expense	208	233	641	681
Other (income) expense	9	6	34	26
Amortization of purchased intangibles	0	0	0	0
Chubb integration expenses	1	16	54	56
Income tax benefit	(89)	(136)	(288)	(323)
Net income (loss)	62	617	1,097	1,225
Comprehensive income (loss)	748	627	2,459	2,687
Other Chubb Limited Subsidiaries
Condensed Statement of Income Captions [Line Items]
Net premiums written	7,902	7,573	22,193	21,207
Net premiums earned	7,807	7,688	21,816	21,690
Net investment income	809	736	2,315	2,109
Equity in earnings of subsidiaries	0	0	0	0
Net realized gains (losses) including OTTI	(2)	102	108	(506)
Losses and loss expenses	6,247	4,269	14,182	12,197
Policy benefits	169	155	500	427
Policy acquisition costs and administrative expenses	2,166	2,259	6,346	6,668
Interest (income) expense	26	12	62	36
Other (income) expense	(122)	(90)	(360)	(98)
Amortization of purchased intangibles	65	4	194	16
Chubb integration expenses	42	87	166	276
Income tax benefit	(2)	407	515	862
Net income (loss)	23	1,423	2,634	2,909
Comprehensive income (loss)	$ 724	$ 1,439	$ 4,018	$ 4,841

Information Provided In Conne73

Information Provided In Connection With Outstanding Debt Of Subsidiaries (Condensed Consolidating Statement Of Cash Flows) (Detail) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017		Sep. 30, 2016
Condensed Cash Flow Statements, Captions [Line Items]
Net cash flows from operating activities	$ 3,411		$ 3,837
Purchases of fixed maturities available for sale	(18,478)		(23,837)
Purchases of fixed maturities held to maturity	(262)		(189)
Purchases of equity securities	(125)		(100)
Sales of fixed maturities available for sale	9,215		13,863
Sales of equity securities	152		963
Maturities and redemptions of fixed maturities available for sale	7,699		6,936
Maturities and redemptions of fixed maturities held to maturity	644		627
Net change in short-term investments	44		11,866
Net derivative instruments settlements	(170)		(181)
Acquisition of subsidiaries (net of cash acquired of nil and $71)	0		(14,248)
Capital contribution			0
Other	(62)		26
Net cash flows used for investing activities	(1,343)		(4,274)
Dividends paid on Common Shares	(978)		(851)
Common Shares repurchased	(707)		0
Repayment of long-term debt	(500)		0
Proceeds from issuance of repurchase agreements	1,798		1,457
Repayments of repurchase agreements	(1,793)		(1,455)
Proceeds from share-based compensation plans	109		117
Dividend to Parent Company	0		0
Advances (to) from affiliates	0		0
Capital contribution			0
Net proceeds from (payments to) affiliated notional cash pooling program	0		0
Policyholder contract deposits	312		473
Policyholder contract withdrawals	(211)		(247)
Other	0		(4)
Net cash flows used for financing activities	(1,970)		(510)
Effect of foreign currency rate changes on cash and cash equivalents	5		42
Net increase (decrease) in cash	103		(905)
Cash – beginning of period	985	[1],[2]	1,775	[3]
Cash – end of period	1,088	[2],[4]	870	[3]
Chubb Limited (Parent Guarantor)
Condensed Cash Flow Statements, Captions [Line Items]
Net cash flows from operating activities	639		3,399
Purchases of fixed maturities available for sale	0		0
Purchases of fixed maturities held to maturity	0		0
Purchases of equity securities	0		0
Sales of fixed maturities available for sale	0		0
Sales of equity securities	0		0
Maturities and redemptions of fixed maturities available for sale	0		0
Maturities and redemptions of fixed maturities held to maturity	0		0
Net change in short-term investments	0		0
Net derivative instruments settlements	0		0
Acquisition of subsidiaries (net of cash acquired of nil and $71)			0
Capital contribution			(2,330)
Other	0		0
Net cash flows used for investing activities	0		(2,330)
Dividends paid on Common Shares	(978)		(851)
Common Shares repurchased	0
Repayment of long-term debt	0
Proceeds from issuance of repurchase agreements	0		0
Repayments of repurchase agreements	0		0
Proceeds from share-based compensation plans	0		0
Dividend to Parent Company	0		0
Advances (to) from affiliates	617		(258)
Capital contribution			0
Net proceeds from (payments to) affiliated notional cash pooling program	(278)	[2]	45	[3]
Policyholder contract deposits	0		0
Policyholder contract withdrawals	0		0
Other			0
Net cash flows used for financing activities	(639)		(1,064)
Effect of foreign currency rate changes on cash and cash equivalents	0		0
Net increase (decrease) in cash	0		5
Cash – beginning of period	1	[1],[2]	1	[3]
Cash – end of period	1	[2],[4]	6	[3]
Chubb INA Holdings Inc (Subsidiary Issuer)
Condensed Cash Flow Statements, Captions [Line Items]
Net cash flows from operating activities	1,472		3,892
Purchases of fixed maturities available for sale	(9)		(154)
Purchases of fixed maturities held to maturity	0		0
Purchases of equity securities	0		0
Sales of fixed maturities available for sale	99		66
Sales of equity securities	0		0
Maturities and redemptions of fixed maturities available for sale	22		59
Maturities and redemptions of fixed maturities held to maturity	0		0
Net change in short-term investments	197		7,627
Net derivative instruments settlements	(13)		(10)
Acquisition of subsidiaries (net of cash acquired of nil and $71)			(14,282)
Capital contribution			(20)
Other	6		(3)
Net cash flows used for investing activities	302		(6,717)
Dividends paid on Common Shares	0		0
Common Shares repurchased	0
Repayment of long-term debt	(500)
Proceeds from issuance of repurchase agreements	0		0
Repayments of repurchase agreements	0		0
Proceeds from share-based compensation plans	0		0
Dividend to Parent Company	0		0
Advances (to) from affiliates	(658)		219
Capital contribution			2,330
Net proceeds from (payments to) affiliated notional cash pooling program	(617)	[2]	280	[3]
Policyholder contract deposits	0		0
Policyholder contract withdrawals	0		0
Other			(4)
Net cash flows used for financing activities	(1,775)		2,825
Effect of foreign currency rate changes on cash and cash equivalents	0		0
Net increase (decrease) in cash	(1)		0
Cash – beginning of period	1	[1],[2]	2	[3]
Cash – end of period	0	[2],[4]	2	[3]
Other Chubb Limited Subsidiaries
Condensed Cash Flow Statements, Captions [Line Items]
Net cash flows from operating activities	3,341		3,918
Purchases of fixed maturities available for sale	(18,469)		(23,683)
Purchases of fixed maturities held to maturity	(262)		(189)
Purchases of equity securities	(125)		(100)
Sales of fixed maturities available for sale	9,116		13,797
Sales of equity securities	152		963
Maturities and redemptions of fixed maturities available for sale	7,677		6,877
Maturities and redemptions of fixed maturities held to maturity	644		627
Net change in short-term investments	(153)		4,239
Net derivative instruments settlements	(157)		(171)
Acquisition of subsidiaries (net of cash acquired of nil and $71)			34
Capital contribution			(2,330)
Other	(68)		29
Net cash flows used for investing activities	(1,645)		93
Dividends paid on Common Shares	0		0
Common Shares repurchased	(707)
Repayment of long-term debt	0
Proceeds from issuance of repurchase agreements	1,798		1,457
Repayments of repurchase agreements	(1,793)		(1,455)
Proceeds from share-based compensation plans	109		117
Dividend to Parent Company	(2,041)		(7,372)
Advances (to) from affiliates	41		39
Capital contribution			2,350
Net proceeds from (payments to) affiliated notional cash pooling program	0	[2]	0	[3]
Policyholder contract deposits	312		473
Policyholder contract withdrawals	(211)		(247)
Other			0
Net cash flows used for financing activities	(2,492)		(4,638)
Effect of foreign currency rate changes on cash and cash equivalents	5		42
Net increase (decrease) in cash	(791)		(585)
Cash – beginning of period	1,965	[1],[2]	2,743	[3]
Cash – end of period	1,174	[2],[4]	2,158	[3]
Consolidation, Eliminations [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Net cash flows from operating activities	(2,041)		(7,372)
Purchases of fixed maturities available for sale	0		0
Purchases of fixed maturities held to maturity	0		0
Purchases of equity securities	0		0
Sales of fixed maturities available for sale	0		0
Sales of equity securities	0		0
Maturities and redemptions of fixed maturities available for sale	0		0
Maturities and redemptions of fixed maturities held to maturity	0		0
Net change in short-term investments	0		0
Net derivative instruments settlements	0		0
Acquisition of subsidiaries (net of cash acquired of nil and $71)			0
Capital contribution			4,680
Other	0		0
Net cash flows used for investing activities	0		4,680
Dividends paid on Common Shares	0		0
Common Shares repurchased	0
Repayment of long-term debt	0
Proceeds from issuance of repurchase agreements	0		0
Repayments of repurchase agreements	0		0
Proceeds from share-based compensation plans	0		0
Dividend to Parent Company	2,041		7,372
Advances (to) from affiliates	0		0
Capital contribution			(4,680)
Net proceeds from (payments to) affiliated notional cash pooling program	895	[2]	(325)
Policyholder contract deposits	0		0
Policyholder contract withdrawals	0		0
Other			0
Net cash flows used for financing activities	2,936		2,367
Effect of foreign currency rate changes on cash and cash equivalents	0		0
Net increase (decrease) in cash	895		(325)
Cash – beginning of period	(982)	[1],[2]	(971)	[3]
Cash – end of period	$ (87)	[2],[4]	$ (1,296)	[3]
[1]	Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At December 31, 2016, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[2]	Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At September 30, 2017 and December 31, 2016, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[3]	Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At September 30, 2016 and December 31, 2015, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.
[4]	Chubb maintains two notional multicurrency cash pools (Pools) with a third-party bank. Various Chubb entities participate in one or the other of the Pools, pursuant to which credit and debit balances in individual Chubb accounts are translated daily into a single currency and pooled on a notional basis. Individual Chubb entities are permitted to overdraw on their individual accounts provided the overall Pool balances do not fall below zero. At September 30, 2017, the cash balance of one or more entities was negative; however, the overall Pool balances were positive.

Information provided in conne74

Information provided in connection with outstanding debt of subsidiaries Parenthetical (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash Acquired from Acquisition	$ 0	$ 71