Chubb (CHB) 10-Q 7 Aug 14 2014 Q2 Quarterly report Financial data

Document_and_Entity_Informatio

Document and Entity Information	6 Months Ended
	Jun. 30, 2014
Document And Entity Information [Abstract]	'
Document Type	'10-Q
Amendment Flag	'false
Document Period End Date	30-Jun-14
Document Fiscal Year Focus	'2014
Document Fiscal Period Focus	'Q2
Trading Symbol	'CB
Entity Registrant Name	'CHUBB CORP
Entity Central Index Key	'0000020171
Current Fiscal Year End Date	'--12-31
Entity Filer Category	'Large Accelerated Filer
Entity Common Stock, Shares Outstanding	240,483,744

Consolidated_Statements_of_Inc

Consolidated Statements of Income (USD $)	3 Months Ended		6 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revenues	'	'	'	'
Premiums Earned	$3,064	$2,995	$6,093	$5,999
Investment Income	351	368	709	740
Other Revenues	2	9	5	12
Realized Investment Gains (Losses), Net	'	'	'	'
Total Other-Than-Temporary Impairment Losses on Investments	-5	-5	-5	-7
Other Realized Investment Gains, Net	130	184	246	324
Total Realized Investment Gains, Net	125	179	241	317
Total Revenues	3,542	3,551	7,048	7,068
Losses and Expenses	'	'	'	'
Losses and Loss Expenses	1,792	1,694	3,637	3,262
Amortization of Deferred Policy Acquisition Costs	630	617	1,252	1,204
Other Insurance Operating Costs and Expenses	366	358	722	717
Investment Expenses	9	13	20	26
Other Expenses	5	11	10	17
Corporate Expenses	62	62	126	130
Total Losses and Expenses	2,864	2,755	5,767	5,356
Income Before Federal and Foreign Income Tax	678	796	1,281	1,712
Federal and Foreign Income Tax	179	217	333	477
Net Income	$499	$579	$948	$1,235
Net Income Per Share	'	'	'	'
Basic	$2.03	$2.22	$3.84	$4.72
Diluted	$2.03	$2.21	$3.83	$4.69
Dividends Declared Per Share	$0.50	$0.44	$1	$0.88

Consolidated_Statements_of_Com

Consolidated Statements of Comprehensive Income (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Statement Of Income And Comprehensive Income [Abstract]	'	'	'	'
Net Income	$499	$579	$948	$1,235
Other Comprehensive Income (Loss), Net of Tax	'	'	'	'
Change in Unrealized Appreciation of Investments	238	-700	473	-696
Change in Postretirement Benefit Costs Not Yet Recognized in Net Income	5	14	11	31
Foreign Currency Translation Gains (Losses)	4	28	-15	-22
Total Other Comprehensive Income (Loss) Net of Tax	247	-658	469	-687
Comprehensive Income (Loss)	$746	($79)	$1,417	$548

Consolidated_Balance_Sheets

Consolidated Balance Sheets (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Assets	'	'
Short Term Investments	$1,845	$2,114
Fixed Maturities (cost $36,313 and $35,959)	38,062	37,091
Equity Securities (cost $1,106 and $1,057)	1,969	1,810
Other Invested Assets	1,595	1,598
TOTAL INVESTED ASSETS	43,471	42,613
Cash	55	52
Accrued Investment Income	417	418
Premiums Receivable	2,420	2,284
Reinsurance Recoverable on Unpaid Losses and Loss Expenses	1,729	1,802
Prepaid Reinsurance Premiums	278	290
Deferred Policy Acquisition Costs	1,286	1,255
Deferred Income Tax	'	47
Goodwill	467	467
Other Assets	1,317	1,205
TOTAL ASSETS	51,440	50,433
Liabilities	'	'
Unpaid Losses and Loss Expenses	23,127	23,146
Unearned Premiums	6,588	6,423
Long Term Debt	3,300	3,300
Dividend Payable to Shareholders	122	110
Deferred Income Tax	259	'
Accrued Expenses and Other Liabilities	1,546	1,357
TOTAL LIABILITIES	34,942	34,336
Shareholders' Equity	'	'
Common Stock - $1 Par Value; 371,980,460 Shares	372	372
Paid-In Surplus	129	171
Retained Earnings	22,604	21,902
Accumulated Other Comprehensive Income	1,504	1,035
Treasury Stock, at Cost - 131,496,716 and 123,673,969 Shares	-8,111	-7,383
TOTAL SHAREHOLDERS' EQUITY	16,498	16,097
TOTAL LIABILITIES AND SHAREHOLDERS' EQUITY	$51,440	$50,433

Consolidated_Balance_Sheets_Pa

Consolidated Balance Sheets (Parenthetical) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, except Share data, unless otherwise specified
Statement Of Financial Position [Abstract]	'	'
Fixed Maturities, cost	$36,313	$35,959
Equity Securities, cost	$1,106	$1,057
Common Stock, Par Value	$1	$1
Common Stock, Shares Issued	371,980,460	371,980,460
Treasury Stock, Shares	131,496,716	123,673,969

Consolidated_Statements_of_Sha

Consolidated Statements of Shareholders' Equity (USD $)	Total	Common Stock [Member]	Paid-In-Surplus [Member]	Retained Earnings [Member]	Unrealized Appreciation of Investments Including Unrealized Other-Than-Temporary Impairment Losses [Member]	Postretirement Benefit Costs Not Yet Recognized in Net Income [Member]	Foreign Currency Translation Gains [Member]	Accumulated Other Comprehensive Income [Member]	Treasury Stock, at Cost [Member]
In Millions
Balance, Beginning of Year at Dec. 31, 2012	'	$372	$178	$20,009	$2,013	($717)	$135	'	($6,163)
Net Income	1,235	'	'	1,235	'	'	'	'	'
Repurchase of Shares	'	'	'	'	'	'	'	'	-649
Changes Related to Stock-Based Employee Compensation (includes tax benefit of $14 and $27)	'	'	-52	'	'	'	'	'	'
Change During Period, Net of Tax	-687	'	'	'	-696	31	-22	'	'
Dividends Declared (per share $1.00 and $.88)	'	'	'	-229	'	'	'	'	'
Shares Issued Under Stock-Based Employee Compensation Plans	'	'	'	'	'	'	'	'	78
Balance, End of Period at Jun. 30, 2013	15,523	372	126	21,015	1,317	-686	113	744	-6,734
Balance, Beginning of Year at Dec. 31, 2013	16,097	372	171	21,902	1,225	-253	63	'	-7,383
Net Income	948	'	'	948	'	'	'	'	'
Repurchase of Shares	'	'	'	'	'	'	'	'	-784
Changes Related to Stock-Based Employee Compensation (includes tax benefit of $14 and $27)	'	'	-42	'	'	'	'	'	'
Change During Period, Net of Tax	469	'	'	'	473	11	-15	'	'
Dividends Declared (per share $1.00 and $.88)	'	'	'	-246	'	'	'	'	'
Shares Issued Under Stock-Based Employee Compensation Plans	'	'	'	'	'	'	'	'	56
Balance, End of Period at Jun. 30, 2014	$16,498	$372	$129	$22,604	$1,698	($242)	$48	$1,504	($8,111)

Consolidated_Statements_of_Sha1

Consolidated Statements of Shareholders' Equity (Parenthetical) (USD $)	6 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Dividends Declared Per Share	$1	$0.88
Paid-In-Surplus [Member]	'	'
Tax Benefit, Stock-Based Employee Compensation	$14	$27
Retained Earnings [Member]	'	'
Dividends Declared Per Share	$1	$0.88

Consolidated_Statements_of_Cas

Consolidated Statements of Cash Flows (USD $)	6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013
Cash Flows from Operating Activities	'	'
Net Income	$948	$1,235
Adjustments to Reconcile Net Income to Net Cash Provided by Operating Activities	'	'
Increase (Decrease) in Unpaid Losses and Loss Expenses, Net	87	-299
Increase in Unearned Premiums, Net	192	158
Increase in Premiums Receivable	-136	-130
Amortization of Premiums and Discounts on Fixed Maturities	93	91
Depreciation	27	28
Realized Investment Gains, Net	-241	-317
Other, Net	-192	-202
Net Cash Provided by Operating Activities	778	564
Cash Flows from Investing Activities	'	'
Proceeds from Fixed Maturities - Sales	2,377	1,138
Proceeds from Fixed Maturities - Maturities, Calls and Redemptions	2,067	2,353
Proceeds from Sales of Equity Securities	136	273
Purchases of Fixed Maturities	-4,884	-4,053
Purchases of Equity Securities	-97	-92
Investments in Other Invested Assets, Net	112	280
Decrease in Short Term Investments, Net	259	514
Change in Receivable or Payable from Security Transactions Not Settled, Net	278	165
Purchases of Property and Equipment, Net	-26	-25
Other, Net	-3	'
Net Cash Provided by Investing Activities	219	553
Cash Flows from Financing Activities	'	'
Repayment of Long Term Debt	'	-275
Decrease in Funds Held Under Deposit Contracts	-1	-4
Proceeds from Issuance of Common Stock Under Stock-Based Employee Compensation Plans	15	36
Repurchase of Shares	-774	-634
Dividends Paid to Shareholders	-234	-223
Net Cash Used in Financing Activities	-994	-1,100
Net Increase in Cash	3	17
Cash at Beginning of Year	52	50
Cash at End of Period	$55	$67

General

General	6 Months Ended
	Jun. 30, 2014
Accounting Policies [Abstract]	'
General	'
	1) General
	The accompanying condensed consolidated financial statements have been prepared in accordance with U.S. generally accepted accounting principles (GAAP) and include the accounts of The Chubb Corporation (Chubb) and its subsidiaries (collectively, the Corporation). Significant intercompany transactions have been eliminated in consolidation.
	The amounts included in this report are unaudited but include those adjustments, consisting of normal recurring items, that management considers necessary for a fair presentation. These condensed consolidated financial statements should be read in conjunction with the consolidated financial statements and related notes in the Notes to Consolidated Financial Statements included in the Corporation’s Annual Report on Form 10-K for the year ended December 31, 2013.

Invested_Assets

Invested Assets	6 Months Ended
	Jun. 30, 2014
Text Block [Abstract]	'
Invested Assets	'
	2) Invested Assets
	(a) The amortized cost and fair value of fixed maturities and equity securities were as follows:
		June 30, 2014
		Amortized			Gross			Gross			Fair
		Cost			Unrealized			Unrealized			Value
					Appreciation			Depreciation
		(in millions)
	Fixed maturities
	Tax exempt	$	18,168		$	1,088		$	36		$	19,220
	Taxable
	U.S. government and government agency and authority obligations		1,245			43			2			1,286
	Corporate bonds		8,809			405			20			9,194
	Foreign government and government agency obligations		6,682			236			13			6,905
	Residential mortgage-backed securities		229			22			1			250
	Commercial mortgage-backed securities		1,180			28			1			1,207
			18,145			734			37			18,842
	Total fixed maturities	$	36,313		$	1,822		$	73		$	38,062
	Equity securities	$	1,106		$	878		$	15		$	1,969
		December 31, 2013
		Amortized			Gross			Gross			Fair
		Cost			Unrealized			Unrealized			Value
					Appreciation			Depreciation
		(in millions)
	Fixed maturities
	Tax exempt	$	17,808		$	802		$	189		$	18,421
	Taxable
	U.S. government and government agency and authority obligations		784			27			9			802
	Corporate bonds		9,032			370			88			9,314
	Foreign government and government agency obligations		6,719			206			35			6,890
	Residential mortgage-backed securities		277			23			1			299
	Commercial mortgage-backed securities		1,339			29			3			1,365
			18,151			655			136			18,670
	Total fixed maturities	$	35,959		$	1,457		$	325		$	37,091
	Equity securities	$	1,057		$	756		$	3		$	1,810
	The fair value and amortized cost of fixed maturities at June 30, 2014 by contractual maturity were as follows:
		Fair			Amortized
		Value			Cost
		(in millions)
	Due in one year or less	$	1,967		$	1,946
	Due after one year through five years		14,182			13,577
	Due after five years through ten years		12,348			11,661
	Due after ten years		8,108			7,720
			36,605			34,904
	Residential mortgage-backed securities		250			229
	Commercial mortgage-backed securities		1,207			1,180
		$	38,062		$	36,313
	Actual maturities could differ from contractual maturities because borrowers may have the right to call or prepay obligations.
	The Corporation’s equity securities comprise a diversified portfolio of primarily U.S. publicly-traded common stocks.
	The Corporation is involved in the normal course of business with variable interest entities (VIEs) primarily as a passive investor in residential mortgage-backed securities, commercial mortgage-backed securities and private equity limited partnerships issued by third party VIEs. The Corporation is not the primary beneficiary of these VIEs. The Corporation’s maximum exposure to loss with respect to these investments is limited to the investment carrying values included in the Corporation’s consolidated balance sheet and any unfunded partnership commitments.
	(b) The components of unrealized appreciation or depreciation, including unrealized other-than-temporary impairment losses, of investments carried at fair value were as follows:
		June 30			December 31
		2014			2013
		(in millions)
	Fixed maturities
	Gross unrealized appreciation	$	1,822		$	1,457
	Gross unrealized depreciation		73			325
			1,749			1,132
	Equity securities
	Gross unrealized appreciation		878			756
	Gross unrealized depreciation		15			3
			863			753
			2,612			1,885
	Deferred income tax liability		914			660
	$	1,698		$	1,225
The following table summarizes, for all investment securities in an unrealized loss position at June 30, 2014, the aggregate fair value and gross unrealized depreciation, including unrealized other-than-temporary impairment losses, by investment category and length of time that individual securities have continuously been in an unrealized loss position.
	Less Than 12 Months						12 Months or More						Total
	Fair			Gross			Fair			Gross			Fair		Gross
	Value			Unrealized			Value			Unrealized			Value		Unrealized
				Depreciation						Depreciation					Depreciation
	(in millions)
Fixed maturities
Tax exempt	$	441		$	5		$	1,069		$	31		$	1,510	$	36
Taxable
U.S. government and government agency and authority obligations		510			—			36			2			546		2
Corporate bonds		502			2			1,097			18			1,599		20
Foreign government and government agency obligations		465			2			500			11			965		13
Residential mortgage-backed securities		2			—			6			1			8		1
Commercial mortgage-backed securities		55			—			40			1			95		1
		1,534			4			1,679			33			3,213		37
Total fixed maturities		1,975			9			2,748			64			4,723		73
Equity securities		62			15			—			—			62		15
	$	2,037		$	24		$	2,748		$	64		$	4,785	$	88
At June 30, 2014, approximately 570 individual fixed maturities and 10 individual equity securities were in an unrealized loss position. The Corporation does not have the intent to sell and it is not more likely than not that the Corporation will be required to sell these fixed maturities before the securities recover to their amortized cost value. In addition, the Corporation believes that none of the declines in the fair values of these fixed maturities relate to credit losses. The Corporation has the intent and ability to hold the equity securities in an unrealized loss position for a period of time sufficient to allow for the recovery of cost. The Corporation believes that none of the declines in the fair value of these fixed maturities and equity securities were other than temporary at June 30, 2014.
The following table summarizes, for all investment securities in an unrealized loss position at December 31, 2013, the aggregate fair value and gross unrealized depreciation, including unrealized other-than-temporary impairment losses, by investment category and length of time that individual securities have continuously been in an unrealized loss position.
	Less Than 12 Months						12 Months or More						Total
	Fair			Gross			Fair			Gross			Fair		Gross
	Value			Unrealized			Value			Unrealized			Value		Unrealized
				Depreciation						Depreciation					Depreciation
	(in millions)
Fixed maturities
Tax exempt	$	3,417		$	144		$	307		$	45		$	3,724	$	189
Taxable
U.S. government and government agency and authority obligations		213			6			35			3			248		9
Corporate bonds		2,526			76			222			12			2,748		88
Foreign government and government agency obligations		1,735			32			75			3			1,810		35
Residential mortgage-backed securities		4			—			14			1			18		1
Commercial mortgage-backed securities		153			1			39			2			192		3
		4,631			115			385			21			5,016		136
Total fixed maturities		8,048			259			692			66			8,740		325
Equity securities		41			3			—			—			41		3
	$	8,089		$	262		$	692		$	66		$	8,781	$	328
The change in unrealized appreciation or depreciation of investments carried at fair value, including the change in unrealized other-than-temporary impairment losses, was as follows:
	Periods Ended June 30
	Second Quarter						Six Months
	2014			2013			2014			2013
	(in millions)
Change in unrealized appreciation of fixed maturities	$	255			$    (1,019	)	$	617		$	(1,215	)
Change in unrealized appreciation of equity securities		111			(57	)		110			145
		366			(1,076	)		727			(1,070	)
Deferred income tax (credit)		128			(376	)		254			(374	)
	$	238		$	(700	)	$	473		$	(696	)
(c) Realized investment gains and losses were as follows:
	Periods Ended June 30
	Second Quarter						Six Months
	2014			2013			2014			2013
	(in millions)
Fixed maturities
Gross realized gains	$	69		$	14		$	77		$	27
Gross realized losses		(17	)		(8	)		(28	)		(10	)
Other-than-temporary impairment losses		(4	)		—			(4	)		—
		48			6			45			17
Equity securities
Gross realized gains		23			119			89			174
Other-than-temporary impairment losses		(1	)		(5	)		(1	)		(7	)
		22			114			88			167
Other invested assets		55			59			108			133
	$	125		$	179		$	241		$	317
(d) As of June 30, 2014 and December 31, 2013, fixed maturities still held by the Corporation for which a portion of their other-than-temporary impairment losses were recognized in other comprehensive income had cumulative credit-related losses of $19 million and $20 million, respectively, recognized in net income.

Comprehensive_Income

Comprehensive Income	6 Months Ended
	Jun. 30, 2014
Equity [Abstract]	'
Comprehensive Income	'
	3) Comprehensive Income
	Comprehensive income is defined as all changes in shareholders’ equity, except those arising from transactions with shareholders. Comprehensive income includes net income and other comprehensive income or loss, which for the Corporation consists of changes in unrealized appreciation or depreciation of investments carried at fair value, changes in unrealized other-than-temporary impairment losses of fixed maturities, changes in postretirement benefit costs not yet recognized in net income and changes in foreign currency translation gains or losses.
	The components of other comprehensive income or loss were as follows:
		Periods Ended June 30, 2014
		Second Quarter									Six Months
		Before			Income			Net of			Before			Income			Net of
		Tax			Tax			Tax			Tax			Tax			Tax
		(in millions)
	Net unrealized holding gains arising during the period	$	436		$	153		$	283		$	860		$	301		$	559
	Reclassification adjustment for net realized gains included in net income		70			25			45			133			47			86
	Net unrealized gains recognized in other comprehensive income		366			128			238			727			254			473
	Reclassification adjustment for the amortization of net actuarial loss and prior service cost included in net income (a)		(8	)		(3	)		(5	)		(17	)		(6	)		(11	)
	Net change in postretirement benefit costs not yet recognized in net income		8			3			5			17			6			11
	Foreign currency translation gains (losses)		6			2			4			(22	)		(7	)		(15	)
	Total other comprehensive income	$	380		$	133		$	247		$	722		$	253		$	469
	(a) Postretirement benefit costs recognized in net income during the period are included among several of the loss and expense components presented in the consolidated statements of income.
		Periods Ended June 30, 2013
		Second Quarter									Six Months
		Before			Income			Net of			Before			Income			Net of
		Tax			Tax			Tax			Tax			Tax			Tax
		(in millions)
	Net unrealized holding losses arising during the period	$	(956	)	$	(334	)	$	(622	)	$	(886	)	$	(310	)	$	(576	)
	Reclassification adjustment for net realized gains included in net income		120			42			78			184			64			120
	Net unrealized losses recognized in other comprehensive loss		(1,076	)		(376	)		(700	)		(1,070	)		(374	)		(696	)
	Postretirement benefit gain (loss) not yet recognized in net income arising during the period		(1	)		(1	)		—			1			—			1
	Reclassification adjustment for the amortization of net actuarial loss and prior service cost included in net income (a)		(23	)		(9	)		(14	)		(47	)		(17	)		(30	)
	Net change in postretirement benefit costs not yet recognized in net income		22			8			14			48			17			31
	Foreign currency translation gains (losses)		42			14			28			(35	)		(13	)		(22	)
	Total other comprehensive loss	$	(1,012	)	$	(354	)	$	(658	)	$	(1,057	)	$	(370	)	$	(687	)
	(a) Postretirement benefit costs recognized in net income during the period are included among several of the loss and expense components presented in the consolidated statements of income.

Segments_Information

Segments Information	6 Months Ended
	Jun. 30, 2014
Segment Reporting [Abstract]	'
Segments Information	'
	4) Segments Information
	The principal business of the Corporation is the sale of property and casualty insurance. The profitability of the property and casualty insurance business depends on the results of both underwriting operations and investments, which are viewed as two distinct operations. The underwriting operations are managed and evaluated separately from the investment function.
	The property and casualty insurance subsidiaries underwrite most lines of property and casualty insurance. Underwriting operations consist of four separate business units: personal insurance, commercial insurance, specialty insurance and reinsurance assumed. The personal segment targets the personal insurance market. The personal classes include automobile, homeowners and other personal coverages. The commercial segment includes those classes of business that are generally available in broad markets and are of a more commodity nature. Commercial classes include multiple peril, casualty, workers’ compensation and property and marine. The specialty segment includes those classes of business that are available in more limited markets since they require specialized underwriting and claim settlement. Specialty classes include professional liability coverages and surety. The reinsurance assumed business has been in runoff since the transfer of the ongoing reinsurance assumed business to a reinsurance company in 2005.
	Corporate and other includes investment income earned on corporate invested assets, corporate expenses and the results of the Corporation’s non-insurance subsidiaries.
	Revenues and income before income tax of each operating segment were as follows:
		Periods Ended June 30
		Second Quarter						Six Months
		2014			2013			2014			2013
		(in millions)
	Revenues
	Property and casualty insurance
	Premiums earned
	Personal insurance	$	1,102		$	1,050		$	2,178		$	2,081
	Commercial insurance		1,305			1,299			2,605			2,607
	Specialty insurance		656			645			1,309			1,311
	Total insurance		3,063			2,994			6,092			5,999
	Reinsurance assumed		1			1			1			—
			3,064			2,995			6,093			5,999
	Investment income		345			361			696			724
	Total property and casualty insurance		3,409			3,356			6,789			6,723
	Corporate and other		8			16			18			28
	Realized investment gains, net		125			179			241			317
	Total revenues	$	3,542		$	3,551		$	7,048		$	7,068
	Income (loss) before income tax
	Property and casualty insurance
	Underwriting
	Personal insurance	$	45		$	75		$	47		$	225
	Commercial insurance		71			124			182			319
	Specialty insurance		140			96			222			191
	Total insurance		256			295			451			735
	Reinsurance assumed		1			6			1			10
			257			301			452			745
	Increase in deferred policy acquisition costs		21			16			34			57
	Underwriting income		278			317			486			802
	Investment income		336			349			677			700
	Other income (charges)		(2	)		9			(4	)		14
	Total property and casualty insurance		612			675			1,159			1,516
	Corporate and other		(59	)		(58	)		(119	)		(121	)
	Realized investment gains, net		125			179			241			317
	Total income before income tax	$	678		$	796		$	1,281		$	1,712

Fair_Values_of_Financial_Instr

Fair Values of Financial Instruments	6 Months Ended
	Jun. 30, 2014
Fair Value Disclosures [Abstract]	'
Fair Values of Financial Instruments	'
	5) Fair Values of Financial Instruments
	Fair values of financial instruments are determined by management using valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs. Fair values are generally measured using quoted prices in active markets for identical assets or liabilities or other inputs, such as quoted prices for similar assets or liabilities, that are observable either directly or indirectly. In those instances where observable inputs are not available, fair values are measured using unobservable inputs for the asset or liability. Unobservable inputs reflect the Corporation’s own assumptions about the assumptions that market participants would use in pricing the asset or liability and are developed based on the best information available in the circumstances. Fair value estimates derived from unobservable inputs are affected by the assumptions used, including the discount rates and the estimated amounts and timing of future cash flows. The derived fair value estimates cannot be substantiated by comparison to independent markets and are not necessarily indicative of the amounts that would be realized in a current market exchange. Certain financial instruments, particularly insurance contracts, are excluded from fair value disclosure requirements.
	The methods and assumptions used to estimate the fair values of financial instruments are as follows:
		(i)	The carrying value of short term investments approximates fair value due to the short maturities of these investments.
		(ii)	Fair values of fixed maturities are determined by management, utilizing prices obtained from a third party, nationally recognized pricing service or, in the case of securities for which prices are not provided by a pricing service, from third party brokers. For fixed maturities that have quoted prices in active markets, market quotations are provided. For fixed maturities that do not trade on a daily basis, the pricing service and brokers provide fair value estimates using a variety of inputs including, but not limited to, benchmark yields, reported trades, broker/dealer quotes, issuer spreads, bids, offers, reference data, prepayment rates and measures of volatility. Management reviews on an ongoing basis the reasonableness of the methodologies used by the relevant pricing service and brokers. In addition, management, using the prices received for the securities from the pricing service and brokers, determines the aggregate portfolio price performance and reviews it against applicable indices. If management believes that significant discrepancies exist, it will discuss these with the relevant pricing service or broker to resolve the discrepancies.
		(iii)	Fair values of equity securities are determined by management, utilizing quoted market prices.
		(iv)	Fair values of long term debt issued by Chubb are determined by management, utilizing prices obtained from a third party, nationally recognized pricing service.
	The carrying values and fair values of financial instruments were as follows:
			June 30, 2014				December 31, 2013
			Carrying		Fair		Carrying		Fair
			Value		Value		Value		Value
			(in millions)
	Assets
	Invested assets
	Short term investments		$	1,845	$	1,845	$	2,114	$	2,114
	Fixed maturities			38,062		38,062		37,091		37,091
	Equity securities			1,969		1,969		1,810		1,810
	Liabilities
	Long term debt			3,300		3,989		3,300		3,806
	At June 30, 2014 and December 31, 2013, a pricing service provided fair value amounts for approximately 99% of the Corporation’s fixed maturities. The prices obtained from a pricing service and brokers generally are non-binding, but are reflective of current market transactions in the applicable financial instruments.
	At June 30, 2014 and December 31, 2013, the Corporation held an insignificant amount of financial instruments in its investment portfolio for which a lack of market liquidity impacted the determination of fair value.
	The fair value hierarchy prioritizes the inputs to valuation techniques used to measure fair value into three broad levels as follows:
	Level 1 – Unadjusted quoted prices in active markets for identical financial instruments.
	Level 2 – Other inputs that are observable for the financial instrument, either directly or indirectly.
	Level 3 – Significant unobservable inputs.
	The fair value of financial instruments categorized based upon the lowest level of input that was significant to the fair value measurement was as follows:
			June 30, 2014
			Level 1		Level 2		Level 3		Total
			(in millions)
	Assets
	Short term investments		$	284	$	1,561	$	—	$	1,845
	Fixed maturities
	Tax exempt			—		19,216		4		19,220
	Taxable
	U.S. government and government agency and authority obligations			—		1,286		—		1,286
	Corporate bonds			—		9,066		128		9,194
	Foreign government and government agency obligations			—		6,896		9		6,905
	Residential mortgage-backed securities			—		246		4		250
	Commercial mortgage-backed securities			—		1,196		11		1,207
				—		18,690		152		18,842
	Total fixed maturities			—		37,906		156		38,062
	Equity securities			1,963		—		6		1,969
			$	2,247	$	39,467	$	162	$	41,876
	Liabilities
	Long term debt		$	—	$	3,989	$	—	$	3,989
			December 31, 2013
			Level 1		Level 2		Level 3		Total
			(in millions)
	Assets
	Short term investments		$	399	$	1,715	$	—	$	2,114
	Fixed maturities
	Tax exempt			—		18,416		5		18,421
	Taxable
	U.S. government and government agency and authority obligations			—		802		—		802
	Corporate bonds			—		9,179		135		9,314
	Foreign government and government agency obligations			—		6,881		9		6,890
	Residential mortgage-backed securities			—		293		6		299
	Commercial mortgage-backed securities			—		1,345		20		1,365
				—		18,500		170		18,670
	Total fixed maturities			—		36,916		175		37,091
	Equity securities			1,803		—		7		1,810
			$	2,202	$	38,631	$	182	$	41,015
	Liabilities
Long term debt		$	—	$	3,806	$	—	$	3,806

Earnings_Per_Share

Earnings Per Share	6 Months Ended
	Jun. 30, 2014
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	6) Earnings Per Share
	The following table sets forth the computation of basic and diluted earnings per share:
		Periods Ended June 30
		Second Quarter				Six Months
		2014		2013		2014		2013
		(in millions, except for
		per share amounts)
	Basic earnings per share:
	Net income	$	499	$	579	$	948	$	1,235
	Weighted average shares outstanding		245.7		260.5		247.1		261.9
	Basic earnings per share	$	2.03	$	2.22	$	3.84	$	4.72
	Diluted earnings per share:
	Net income	$	499	$	579	$	948	$	1,235
	Weighted average shares outstanding		245.7		260.5		247.1		261.9
	Additional shares from assumed issuance of shares under stock-based compensation awards		0.5		1		0.6		1.3
	Weighted average shares and potential shares assumed outstanding for computing diluted earnings per share		246.2		261.5		247.7		263.2
	Diluted earnings per share	$	2.03	$	2.21	$	3.83	$	4.69

Invested_Assets_Tables

Invested Assets (Tables)	6 Months Ended
	Jun. 30, 2014
Text Block [Abstract]	'
Amortized Cost and Fair Value of Fixed Maturities and Equity Securities	'
	(a) The amortized cost and fair value of fixed maturities and equity securities were as follows:
		June 30, 2014
		Amortized			Gross			Gross			Fair
		Cost			Unrealized			Unrealized			Value
					Appreciation			Depreciation
		(in millions)
	Fixed maturities
	Tax exempt	$	18,168		$	1,088		$	36		$	19,220
	Taxable
	U.S. government and government agency and authority obligations		1,245			43			2			1,286
	Corporate bonds		8,809			405			20			9,194
	Foreign government and government agency obligations		6,682			236			13			6,905
	Residential mortgage-backed securities		229			22			1			250
	Commercial mortgage-backed securities		1,180			28			1			1,207
			18,145			734			37			18,842
	Total fixed maturities	$	36,313		$	1,822		$	73		$	38,062
	Equity securities	$	1,106		$	878		$	15		$	1,969
		December 31, 2013
		Amortized			Gross			Gross			Fair
		Cost			Unrealized			Unrealized			Value
					Appreciation			Depreciation
		(in millions)
	Fixed maturities
	Tax exempt	$	17,808		$	802		$	189		$	18,421
	Taxable
	U.S. government and government agency and authority obligations		784			27			9			802
	Corporate bonds		9,032			370			88			9,314
	Foreign government and government agency obligations		6,719			206			35			6,890
	Residential mortgage-backed securities		277			23			1			299
	Commercial mortgage-backed securities		1,339			29			3			1,365
			18,151			655			136			18,670
	Total fixed maturities	$	35,959		$	1,457		$	325		$	37,091
	Equity securities	$	1,057		$	756		$	3		$	1,810
Fair Value and Amortized Cost of Fixed Maturities by Contractual Maturity	'
	The fair value and amortized cost of fixed maturities at June 30, 2014 by contractual maturity were as follows:
		Fair			Amortized
		Value			Cost
		(in millions)
	Due in one year or less	$	1,967		$	1,946
	Due after one year through five years		14,182			13,577
	Due after five years through ten years		12,348			11,661
	Due after ten years		8,108			7,720
			36,605			34,904
	Residential mortgage-backed securities		250			229
	Commercial mortgage-backed securities		1,207			1,180
		$	38,062		$	36,313
Components of Unrealized Appreciation or Depreciation of Investments	'
	(b) The components of unrealized appreciation or depreciation, including unrealized other-than-temporary impairment losses, of investments carried at fair value were as follows:
		June 30			December 31
		2014			2013
		(in millions)
	Fixed maturities
	Gross unrealized appreciation	$	1,822		$	1,457
	Gross unrealized depreciation		73			325
			1,749			1,132
	Equity securities
	Gross unrealized appreciation		878			756
	Gross unrealized depreciation		15			3
			863			753
			2,612			1,885
	Deferred income tax liability		914			660
		$	1,698		$	1,225
Fair Value and Gross Unrealized Depreciation of Investments in Unrealized Loss Position	'
	The following table summarizes, for all investment securities in an unrealized loss position at June 30, 2014, the aggregate fair value and gross unrealized depreciation, including unrealized other-than-temporary impairment losses, by investment category and length of time that individual securities have continuously been in an unrealized loss position.
		Less Than 12 Months						12 Months or More						Total
		Fair			Gross			Fair			Gross			Fair		Gross
		Value			Unrealized			Value			Unrealized			Value		Unrealized
					Depreciation						Depreciation					Depreciation
		(in millions)
	Fixed maturities
	Tax exempt	$	441		$	5		$	1,069		$	31		$	1,510	$	36
	Taxable
	U.S. government and government agency and authority obligations		510			—			36			2			546		2
	Corporate bonds		502			2			1,097			18			1,599		20
	Foreign government and government agency obligations		465			2			500			11			965		13
	Residential mortgage-backed securities		2			—			6			1			8		1
	Commercial mortgage-backed securities		55			—			40			1			95		1
			1,534			4			1,679			33			3,213		37
	Total fixed maturities		1,975			9			2,748			64			4,723		73
	Equity securities		62			15			—			—			62		15
		$	2,037		$	24		$	2,748		$	64		$	4,785	$	88
	At June 30, 2014, approximately 570 individual fixed maturities and 10 individual equity securities were in an unrealized loss position. The Corporation does not have the intent to sell and it is not more likely than not that the Corporation will be required to sell these fixed maturities before the securities recover to their amortized cost value. In addition, the Corporation believes that none of the declines in the fair values of these fixed maturities relate to credit losses. The Corporation has the intent and ability to hold the equity securities in an unrealized loss position for a period of time sufficient to allow for the recovery of cost. The Corporation believes that none of the declines in the fair value of these fixed maturities and equity securities were other than temporary at June 30, 2014.
	The following table summarizes, for all investment securities in an unrealized loss position at December 31, 2013, the aggregate fair value and gross unrealized depreciation, including unrealized other-than-temporary impairment losses, by investment category and length of time that individual securities have continuously been in an unrealized loss position.
		Less Than 12 Months						12 Months or More						Total
		Fair			Gross			Fair			Gross			Fair		Gross
		Value			Unrealized			Value			Unrealized			Value		Unrealized
					Depreciation						Depreciation					Depreciation
		(in millions)
	Fixed maturities
	Tax exempt	$	3,417		$	144		$	307		$	45		$	3,724	$	189
	Taxable
	U.S. government and government agency and authority obligations		213			6			35			3			248		9
	Corporate bonds		2,526			76			222			12			2,748		88
	Foreign government and government agency obligations		1,735			32			75			3			1,810		35
	Residential mortgage-backed securities		4			—			14			1			18		1
	Commercial mortgage-backed securities		153			1			39			2			192		3
			4,631			115			385			21			5,016		136
	Total fixed maturities		8,048			259			692			66			8,740		325
	Equity securities		41			3			—			—			41		3
		$	8,089		$	262		$	692		$	66		$	8,781	$	328
Change in Unrealized Appreciation or Depreciation of Investments Carried at Fair Value	'
	The change in unrealized appreciation or depreciation of investments carried at fair value, including the change in unrealized other-than-temporary impairment losses, was as follows:
		Periods Ended June 30
		Second Quarter						Six Months
		2014			2013			2014			2013
		(in millions)
	Change in unrealized appreciation of fixed maturities	$	255			$    (1,019	)	$	617		$	(1,215	)
	Change in unrealized appreciation of equity securities		111			(57	)		110			145
			366			(1,076	)		727			(1,070	)
	Deferred income tax (credit)		128			(376	)		254			(374	)
		$	238		$	(700	)	$	473		$	(696	)
Realized Investment Gains and Losses	'
	(c) Realized investment gains and losses were as follows:
		Periods Ended June 30
		Second Quarter						Six Months
		2014			2013			2014			2013
		(in millions)
	Fixed maturities
	Gross realized gains	$	69		$	14		$	77		$	27
	Gross realized losses		(17	)		(8	)		(28	)		(10	)
	Other-than-temporary impairment losses		(4	)		—			(4	)		—
			48			6			45			17
	Equity securities
	Gross realized gains		23			119			89			174
	Other-than-temporary impairment losses		(1	)		(5	)		(1	)		(7	)
			22			114			88			167
	Other invested assets		55			59			108			133
		$	125		$	179		$	241		$	317

Comprehensive_Income_Tables

Comprehensive Income (Tables)	6 Months Ended
	Jun. 30, 2014
Equity [Abstract]	'
Components of Other Comprehensive Income or Loss	'
	The components of other comprehensive income or loss were as follows:
		Periods Ended June 30, 2014
		Second Quarter									Six Months
		Before			Income			Net of			Before			Income			Net of
		Tax			Tax			Tax			Tax			Tax			Tax
		(in millions)
	Net unrealized holding gains arising during the period	$	436		$	153		$	283		$	860		$	301		$	559
	Reclassification adjustment for net realized gains included in net income		70			25			45			133			47			86
	Net unrealized gains recognized in other comprehensive income		366			128			238			727			254			473
	Reclassification adjustment for the amortization of net actuarial loss and prior service cost included in net income (a)		(8	)		(3	)		(5	)		(17	)		(6	)		(11	)
	Net change in postretirement benefit costs not yet recognized in net income		8			3			5			17			6			11
	Foreign currency translation gains (losses)		6			2			4			(22	)		(7	)		(15	)
	Total other comprehensive income	$	380		$	133		$	247		$	722		$	253		$	469
	(a) Postretirement benefit costs recognized in net income during the period are included among several of the loss and expense components presented in the consolidated statements of income.
		Periods Ended June 30, 2013
		Second Quarter									Six Months
		Before			Income			Net of			Before			Income			Net of
		Tax			Tax			Tax			Tax			Tax			Tax
		(in millions)
	Net unrealized holding losses arising during the period	$	(956	)	$	(334	)	$	(622	)	$	(886	)	$	(310	)	$	(576	)
	Reclassification adjustment for net realized gains included in net income		120			42			78			184			64			120
	Net unrealized losses recognized in other comprehensive loss		(1,076	)		(376	)		(700	)		(1,070	)		(374	)		(696	)
	Postretirement benefit gain (loss) not yet recognized in net income arising during the period		(1	)		(1	)		—			1			—			1
	Reclassification adjustment for the amortization of net actuarial loss and prior service cost included in net income (a)		(23	)		(9	)		(14	)		(47	)		(17	)		(30	)
	Net change in postretirement benefit costs not yet recognized in net income		22			8			14			48			17			31
	Foreign currency translation gains (losses)		42			14			28			(35	)		(13	)		(22	)
	Total other comprehensive loss	$	(1,012	)	$	(354	)	$	(658	)	$	(1,057	)	$	(370	)	$	(687	)
	(a) Postretirement benefit costs recognized in net income during the period are included among several of the loss and expense components presented in the consolidated statements of income.

Segments_Information_Tables

Segments Information (Tables)	6 Months Ended
	Jun. 30, 2014
Segment Reporting [Abstract]	'
Revenues and Income Before Income Tax of Each Operating Segment	'
	Revenues and income before income tax of each operating segment were as follows:
		Periods Ended June 30
		Second Quarter						Six Months
		2014			2013			2014			2013
		(in millions)
	Revenues
	Property and casualty insurance
	Premiums earned
	Personal insurance	$	1,102		$	1,050		$	2,178		$	2,081
	Commercial insurance		1,305			1,299			2,605			2,607
	Specialty insurance		656			645			1,309			1,311
	Total insurance		3,063			2,994			6,092			5,999
	Reinsurance assumed		1			1			1			—
			3,064			2,995			6,093			5,999
	Investment income		345			361			696			724
	Total property and casualty insurance		3,409			3,356			6,789			6,723
	Corporate and other		8			16			18			28
	Realized investment gains, net		125			179			241			317
	Total revenues	$	3,542		$	3,551		$	7,048		$	7,068
	Income (loss) before income tax
	Property and casualty insurance
	Underwriting
	Personal insurance	$	45		$	75		$	47		$	225
	Commercial insurance		71			124			182			319
	Specialty insurance		140			96			222			191
	Total insurance		256			295			451			735
	Reinsurance assumed		1			6			1			10
			257			301			452			745
	Increase in deferred policy acquisition costs		21			16			34			57
	Underwriting income		278			317			486			802
	Investment income		336			349			677			700
	Other income (charges)		(2	)		9			(4	)		14
	Total property and casualty insurance		612			675			1,159			1,516
	Corporate and other		(59	)		(58	)		(119	)		(121	)
	Realized investment gains, net		125			179			241			317
	Total income before income tax	$	678		$	796		$	1,281		$	1,712

Fair_Values_of_Financial_Instr1

Fair Values of Financial Instruments (Tables)	6 Months Ended
	Jun. 30, 2014
Fair Value Disclosures [Abstract]	'
Carrying Values and Fair Values of Financial Instruments	'
	The carrying values and fair values of financial instruments were as follows:
		June 30, 2014				December 31, 2013
		Carrying		Fair		Carrying		Fair
		Value		Value		Value		Value
		(in millions)
	Assets
	Invested assets
	Short term investments	$	1,845	$	1,845	$	2,114	$	2,114
	Fixed maturities		38,062		38,062		37,091		37,091
	Equity securities		1,969		1,969		1,810		1,810
	Liabilities
	Long term debt		3,300		3,989		3,300		3,806
Fair Value of Financial Instruments Categorized Based Upon Lowest Level of Input	'
	The fair value of financial instruments categorized based upon the lowest level of input that was significant to the fair value measurement was as follows:
		June 30, 2014
		Level 1		Level 2		Level 3		Total
		(in millions)
	Assets
	Short term investments	$	284	$	1,561	$	—	$	1,845
	Fixed maturities
	Tax exempt		—		19,216		4		19,220
	Taxable
	U.S. government and government agency and authority obligations		—		1,286		—		1,286
	Corporate bonds		—		9,066		128		9,194
	Foreign government and government agency obligations		—		6,896		9		6,905
	Residential mortgage-backed securities		—		246		4		250
	Commercial mortgage-backed securities		—		1,196		11		1,207
			—		18,690		152		18,842
	Total fixed maturities		—		37,906		156		38,062
	Equity securities		1,963		—		6		1,969
		$	2,247	$	39,467	$	162	$	41,876
	Liabilities
	Long term debt	$	—	$	3,989	$	—	$	3,989
		December 31, 2013
		Level 1		Level 2		Level 3		Total
		(in millions)
	Assets
	Short term investments	$	399	$	1,715	$	—	$	2,114
	Fixed maturities
	Tax exempt		—		18,416		5		18,421
	Taxable
	U.S. government and government agency and authority obligations		—		802		—		802
	Corporate bonds		—		9,179		135		9,314
	Foreign government and government agency obligations		—		6,881		9		6,890
	Residential mortgage-backed securities		—		293		6		299
	Commercial mortgage-backed securities		—		1,345		20		1,365
			—		18,500		170		18,670
	Total fixed maturities		—		36,916		175		37,091
	Equity securities		1,803		—		7		1,810
		$	2,202	$	38,631	$	182	$	41,015
	Liabilities
	Long term debt	$	—	$	3,806	$	—	$	3,806

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2014
Earnings Per Share [Abstract]	'
Computation of Basic and Diluted Earnings Per Share	'
	The following table sets forth the computation of basic and diluted earnings per share:
		Periods Ended June 30
		Second Quarter				Six Months
		2014		2013		2014		2013
		(in millions, except for
		per share amounts)
	Basic earnings per share:
	Net income	$	499	$	579	$	948	$	1,235
	Weighted average shares outstanding		245.7		260.5		247.1		261.9
	Basic earnings per share	$	2.03	$	2.22	$	3.84	$	4.72
	Diluted earnings per share:
	Net income	$	499	$	579	$	948	$	1,235
	Weighted average shares outstanding		245.7		260.5		247.1		261.9
	Additional shares from assumed issuance of shares under stock-based compensation awards		0.5		1		0.6		1.3
	Weighted average shares and potential shares assumed outstanding for computing diluted earnings per share		246.2		261.5		247.7		263.2
	Diluted earnings per share	$	2.03	$	2.21	$	3.83	$	4.69

Invested_Assets_Amortized_Cost

Invested Assets - Amortized Cost and Fair Value of Fixed Maturities and Equity Securities (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Investment Holdings [Line Items]	'	'
Tax exempt, Amortized Cost	$18,168	$17,808
Taxable, Amortized Cost	18,145	18,151
Total fixed maturities, Amortized Cost	36,313	35,959
Equity securities, Amortized Cost	1,106	1,057
Tax exempt, Gross Unrealized Appreciation	1,088	802
Taxable, Gross Unrealized Appreciation	734	655
Total fixed maturities, Gross Unrealized Appreciation	1,822	1,457
Equity securities, Gross Unrealized Appreciation	878	756
Tax exempt, Gross Unrealized Depreciation	36	189
Taxable, Gross Unrealized Depreciation	37	136
Total fixed maturities, Gross Unrealized Depreciation	73	325
Equity securities, Gross Unrealized Depreciation	15	3
Tax exempt, Fair Value	19,220	18,421
Taxable, Fair Value	18,842	18,670
Total fixed maturities, Fair Value	38,062	37,091
Equity securities, Fair Value	1,969	1,810
U.S. Government and Government Agency and Authority Obligations [Member]	'	'
Investment Holdings [Line Items]	'	'
Taxable, Amortized Cost	1,245	784
Taxable, Gross Unrealized Appreciation	43	27
Taxable, Gross Unrealized Depreciation	2	9
Taxable, Fair Value	1,286	802
Corporate Bonds [Member]	'	'
Investment Holdings [Line Items]	'	'
Taxable, Amortized Cost	8,809	9,032
Taxable, Gross Unrealized Appreciation	405	370
Taxable, Gross Unrealized Depreciation	20	88
Taxable, Fair Value	9,194	9,314
Foreign Government and Government Agency Obligations [Member]	'	'
Investment Holdings [Line Items]	'	'
Taxable, Amortized Cost	6,682	6,719
Taxable, Gross Unrealized Appreciation	236	206
Taxable, Gross Unrealized Depreciation	13	35
Taxable, Fair Value	6,905	6,890
Residential Mortgage-backed Securities [Member]	'	'
Investment Holdings [Line Items]	'	'
Taxable, Amortized Cost	229	277
Taxable, Gross Unrealized Appreciation	22	23
Taxable, Gross Unrealized Depreciation	1	1
Taxable, Fair Value	250	299
Commercial Mortgage-backed Securities [Member]	'	'
Investment Holdings [Line Items]	'	'
Taxable, Amortized Cost	1,180	1,339
Taxable, Gross Unrealized Appreciation	28	29
Taxable, Gross Unrealized Depreciation	1	3
Taxable, Fair Value	$1,207	$1,365

Invested_Assets_Fair_Value_and

Invested Assets - Fair Value and Amortized Cost of Fixed Maturities by Contractual Maturity (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Schedule of Available-For-Sale Securities [Line Items]	'	'
Due in one year or less, Fair Value	$1,967	'
Due after one year through five years, Fair Value	14,182	'
Due after five years through ten years, Fair Value	12,348	'
Due after ten years, Fair Value	8,108	'
Subtotal fixed maturities, Fair Value	36,605	'
Total fixed maturities, Fair Value	38,062	37,091
Due in one year or less, Amortized Cost	1,946	'
Due after one year through five years, Amortized Cost	13,577	'
Due after five years through ten years, Amortized Cost	11,661	'
Due after ten years, Amortized Cost	7,720	'
Subtotal fixed maturities, Amortized Cost	34,904	'
Total fixed maturities, Amortized Cost	36,313	35,959
Residential Mortgage-backed Securities [Member]	'	'
Schedule of Available-For-Sale Securities [Line Items]	'	'
Taxable, Fair Value	250	'
Taxable, Amortized Cost	229	'
Commercial Mortgage-backed Securities [Member]	'	'
Schedule of Available-For-Sale Securities [Line Items]	'	'
Taxable, Fair Value	1,207	'
Taxable, Amortized Cost	$1,180	'

Invested_Assets_Components_of_

Invested Assets - Components of Unrealized Appreciation or Depreciation of Investments (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Investments Debt And Equity Securities [Abstract]	'	'
Fixed maturities, Gross unrealized appreciation	$1,822	$1,457
Fixed maturities, Gross unrealized depreciation	73	325
Fixed maturities, Unrealized appreciation (depreciation), Net	1,749	1,132
Equity securities, Gross Unrealized Appreciation	878	756
Equity securities, Gross Unrealized Depreciation	15	3
Equity securities, Unrealized appreciation (depreciation), Net	863	753
Total fixed maturities and equity securities, Unrealized appreciation (depreciation), Net	2,612	1,885
Deferred income tax liability	914	660
Total fixed maturities and equity securities, Unrealized appreciation (depreciation), Net of tax	$1,698	$1,225

Invested_Assets_Fair_Value_and1

Invested Assets - Fair Value and Gross Unrealized Depreciation of Investments in Unrealized Loss Position (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Investment Holdings [Line Items]	'	'
Investment securities, Continuous unrealized loss position, Less Than 12 Months, Fair Value	$2,037	$8,089
Investment securities, Continuous unrealized loss position, Less Than 12 Months, Gross Unrealized Depreciation	24	262
Investment securities, Continuous unrealized loss position, 12 Months or More, Fair Value	2,748	692
Investment securities, Continuous unrealized loss position, 12 Months or More, Gross Unrealized Depreciation	64	66
Investment securities, Continuous unrealized loss position, Fair Value, Total	4,785	8,781
Investment securities, Continuous unrealized loss position, Gross Unrealized Depreciation, Total	88	328
Fixed Maturities [Member]	'	'
Investment Holdings [Line Items]	'	'
Investment securities, Continuous unrealized loss position, Less Than 12 Months, Fair Value	1,975	8,048
Investment securities, Continuous unrealized loss position, Less Than 12 Months, Gross Unrealized Depreciation	9	259
Investment securities, Continuous unrealized loss position, 12 Months or More, Fair Value	2,748	692
Investment securities, Continuous unrealized loss position, 12 Months or More, Gross Unrealized Depreciation	64	66
Investment securities, Continuous unrealized loss position, Fair Value, Total	4,723	8,740
Investment securities, Continuous unrealized loss position, Gross Unrealized Depreciation, Total	73	325
Equity Securities [Member]	'	'
Investment Holdings [Line Items]	'	'
Investment securities, Continuous unrealized loss position, Less Than 12 Months, Fair Value	62	41
Investment securities, Continuous unrealized loss position, Less Than 12 Months, Gross Unrealized Depreciation	15	3
Investment securities, Continuous unrealized loss position, Fair Value, Total	62	41
Investment securities, Continuous unrealized loss position, Gross Unrealized Depreciation, Total	15	3
Tax Exempt [Member] | Fixed Maturities [Member]	'	'
Investment Holdings [Line Items]	'	'
Investment securities, Continuous unrealized loss position, Less Than 12 Months, Fair Value	441	3,417
Investment securities, Continuous unrealized loss position, Less Than 12 Months, Gross Unrealized Depreciation	5	144
Investment securities, Continuous unrealized loss position, 12 Months or More, Fair Value	1,069	307
Investment securities, Continuous unrealized loss position, 12 Months or More, Gross Unrealized Depreciation	31	45
Investment securities, Continuous unrealized loss position, Fair Value, Total	1,510	3,724
Investment securities, Continuous unrealized loss position, Gross Unrealized Depreciation, Total	36	189
Taxable [Member] | Fixed Maturities [Member]	'	'
Investment Holdings [Line Items]	'	'
Investment securities, Continuous unrealized loss position, Less Than 12 Months, Fair Value	1,534	4,631
Investment securities, Continuous unrealized loss position, Less Than 12 Months, Gross Unrealized Depreciation	4	115
Investment securities, Continuous unrealized loss position, 12 Months or More, Fair Value	1,679	385
Investment securities, Continuous unrealized loss position, 12 Months or More, Gross Unrealized Depreciation	33	21
Investment securities, Continuous unrealized loss position, Fair Value, Total	3,213	5,016
Investment securities, Continuous unrealized loss position, Gross Unrealized Depreciation, Total	37	136
Taxable [Member] | U.S. Government and Government Agency and Authority Obligations [Member] | Fixed Maturities [Member]	'	'
Investment Holdings [Line Items]	'	'
Investment securities, Continuous unrealized loss position, Less Than 12 Months, Fair Value	510	213
Investment securities, Continuous unrealized loss position, Less Than 12 Months, Gross Unrealized Depreciation	'	6
Investment securities, Continuous unrealized loss position, 12 Months or More, Fair Value	36	35
Investment securities, Continuous unrealized loss position, 12 Months or More, Gross Unrealized Depreciation	2	3
Investment securities, Continuous unrealized loss position, Fair Value, Total	546	248
Investment securities, Continuous unrealized loss position, Gross Unrealized Depreciation, Total	2	9
Taxable [Member] | Corporate Bonds [Member] | Fixed Maturities [Member]	'	'
Investment Holdings [Line Items]	'	'
Investment securities, Continuous unrealized loss position, Less Than 12 Months, Fair Value	502	2,526
Investment securities, Continuous unrealized loss position, Less Than 12 Months, Gross Unrealized Depreciation	2	76
Investment securities, Continuous unrealized loss position, 12 Months or More, Fair Value	1,097	222
Investment securities, Continuous unrealized loss position, 12 Months or More, Gross Unrealized Depreciation	18	12
Investment securities, Continuous unrealized loss position, Fair Value, Total	1,599	2,748
Investment securities, Continuous unrealized loss position, Gross Unrealized Depreciation, Total	20	88
Taxable [Member] | Foreign Government and Government Agency Obligations [Member] | Fixed Maturities [Member]	'	'
Investment Holdings [Line Items]	'	'
Investment securities, Continuous unrealized loss position, Less Than 12 Months, Fair Value	465	1,735
Investment securities, Continuous unrealized loss position, Less Than 12 Months, Gross Unrealized Depreciation	2	32
Investment securities, Continuous unrealized loss position, 12 Months or More, Fair Value	500	75
Investment securities, Continuous unrealized loss position, 12 Months or More, Gross Unrealized Depreciation	11	3
Investment securities, Continuous unrealized loss position, Fair Value, Total	965	1,810
Investment securities, Continuous unrealized loss position, Gross Unrealized Depreciation, Total	13	35
Residential Mortgage-backed Securities [Member] | Taxable [Member] | Fixed Maturities [Member]	'	'
Investment Holdings [Line Items]	'	'
Investment securities, Continuous unrealized loss position, Less Than 12 Months, Fair Value	2	4
Investment securities, Continuous unrealized loss position, 12 Months or More, Fair Value	6	14
Investment securities, Continuous unrealized loss position, 12 Months or More, Gross Unrealized Depreciation	1	1
Investment securities, Continuous unrealized loss position, Fair Value, Total	8	18
Investment securities, Continuous unrealized loss position, Gross Unrealized Depreciation, Total	1	1
Commercial Mortgage-backed Securities [Member] | Taxable [Member] | Fixed Maturities [Member]	'	'
Investment Holdings [Line Items]	'	'
Investment securities, Continuous unrealized loss position, Less Than 12 Months, Fair Value	55	153
Investment securities, Continuous unrealized loss position, Less Than 12 Months, Gross Unrealized Depreciation	'	1
Investment securities, Continuous unrealized loss position, 12 Months or More, Fair Value	40	39
Investment securities, Continuous unrealized loss position, 12 Months or More, Gross Unrealized Depreciation	1	2
Investment securities, Continuous unrealized loss position, Fair Value, Total	95	192
Investment securities, Continuous unrealized loss position, Gross Unrealized Depreciation, Total	$1	$3

Invested_Assets_Additional_Inf

Invested Assets - Additional Information (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified	Investment
Investments Debt And Equity Securities [Abstract]	'	'
Approximate number of individual fixed maturities in unrealized loss position	570	'
Approximate number of individual equity securities in unrealized loss position	10	'
Cumulative credit-related losses recognized in net income	$19	$20

Invested_Assets_Change_in_Unre

Invested Assets - Change in Unrealized Appreciation or Depreciation of Investments Carried at Fair Value (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Investments Debt And Equity Securities [Abstract]	'	'	'	'
Change in unrealized appreciation of fixed maturities	$255	($1,019)	$617	($1,215)
Change in unrealized appreciation of equity securities	111	-57	110	145
Change in unrealized appreciation of fixed maturities and equity securities	366	-1,076	727	-1,070
Deferred income tax (credit)	128	-376	254	-374
Total change in unrealized appreciation (depreciation) of fixed maturities and equity securities, Net of tax	$238	($700)	$473	($696)

Invested_Assets_Realized_Inves

Invested Assets - Realized Investment Gains and Losses (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Investments Debt And Equity Securities [Abstract]	'	'	'	'
Fixed maturities, Gross realized gains	$69	$14	$77	$27
Fixed maturities, Gross realized losses	-17	-8	-28	-10
Fixed maturities, Other-than-temporary impairment losses	-4	'	-4	'
Total fixed maturities	48	6	45	17
Equity securities, Gross realized gains	23	119	89	174
Equity securities, Other-than-temporary impairment losses	-1	-5	-1	-7
Total equity securities	22	114	88	167
Other invested assets	55	59	108	133
Total Realized Investment Gains, Net	$125	$179	$241	$317

Comprehensive_Income_Component

Comprehensive Income - Components of Other Comprehensive Income or Loss (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Statement Of Income And Comprehensive Income [Abstract]	'	'	'	'
Net unrealized holding gains (losses) arising during the period, Before Tax	$436	($956)	$860	($886)
Reclassification adjustment for net realized gains included in net income, Before Tax	70	120	133	184
Net unrealized gains (losses) recognized in other comprehensive income, Before Tax	366	-1,076	727	-1,070
Postretirement benefit costs not yet recognized in net income arising during the period, Before Tax	'	-1	'	1
Reclassification adjustment for the amortization of net actuarial loss and prior service cost included in net income, Before Tax	-8	-23	-17	-47
Net change in postretirement benefit costs not yet recognized in net income, Before Tax	8	22	17	48
Foreign currency translation gains (losses), Before Tax	6	42	-22	-35
Total other comprehensive Income (loss), Before Tax	380	-1,012	722	-1,057
Net unrealized holding gains (losses) arising during the period, Income Tax	153	-334	301	-310
Reclassification adjustment for net realized gains included in net income, Income Tax	25	42	47	64
Net unrealized gains (losses) recognized in other comprehensive income, Income Tax	128	-376	254	-374
Postretirement benefit costs not yet recognized in net income arising during the period, Income Tax	'	-1	'	'
Reclassification adjustment for the amortization of net actuarial loss and prior service cost included in net income, Income Tax	-3	-9	-6	-17
Net change in postretirement benefit costs not yet recognized in net income, Income Tax	3	8	6	17
Foreign currency translation gains (losses), Income Tax	2	14	-7	-13
Total other comprehensive Income (loss), Income Tax	133	-354	253	-370
Net unrealized holding gains (losses) arising during the period, Net of Tax	283	-622	559	-576
Reclassification adjustment for net realized gains included in net income, Net of Tax	45	78	86	120
Net unrealized gains (losses) recognized in other comprehensive income or loss, Net of Tax	238	-700	473	-696
Postretirement benefit gain (loss) not yet recognized in net income arising during the period, Net of Tax	'	'	'	1
Reclassification adjustment for the amortization of net actuarial loss and prior service cost included in net income, Net of Tax	-5	-14	-11	-30
Net change in postretirement benefit costs not yet recognized in net income, Net of Tax	5	14	11	31
Foreign currency translation gains (losses), Net of Tax	4	28	-15	-22
Total Other Comprehensive Income (Loss) Net of Tax	$247	($658)	$469	($687)

Segments_Information_Additiona

Segments Information - Additional Information (Detail)	6 Months Ended
	Jun. 30, 2014
	Operations
	Business_Unit
Segment Reporting [Abstract]	'
Number of segment operations	2
Number of business units	4

Segments_Information_Revenues_

Segments Information - Revenues and Income Before Income Tax of Each Operating Segment (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revenues	'	'	'	'
Premiums earned related to insurance business	$3,063	$2,994	$6,092	$5,999
Investment Income	351	368	709	740
Premiums earned related to reinsurance assumed	1	1	1	'
Net Premiums earned	3,064	2,995	6,093	5,999
Corporate and other	8	16	18	28
Realized investment gains, net	125	179	241	317
Total Revenues	3,542	3,551	7,048	7,068
Insurance underwriting income (loss)	256	295	451	735
Reinsurance assumed underwriting income	1	6	1	10
Underwriting income before deferred policy acquisition costs	257	301	452	745
Increase in deferred policy acquisition costs	21	16	34	57
Underwriting income	278	317	486	802
Total property and casualty insurance	612	675	1,159	1,516
Corporate and other	-59	-58	-119	-121
Realized investment gains, net	125	179	241	317
Income Before Federal and Foreign Income Tax	678	796	1,281	1,712
Property and Casualty Insurance [Member]	'	'	'	'
Revenues	'	'	'	'
Investment Income	345	361	696	724
Total Revenues	3,409	3,356	6,789	6,723
Investment income	336	349	677	700
Other income (charges)	-2	9	-4	14
Operating Segments [Member] | Personal Insurance [Member]	'	'	'	'
Revenues	'	'	'	'
Premiums earned related to insurance business	1,102	1,050	2,178	2,081
Insurance underwriting income (loss)	45	75	47	225
Operating Segments [Member] | Commercial Insurance [Member]	'	'	'	'
Revenues	'	'	'	'
Premiums earned related to insurance business	1,305	1,299	2,605	2,607
Insurance underwriting income (loss)	71	124	182	319
Operating Segments [Member] | Specialty Insurance [Member]	'	'	'	'
Revenues	'	'	'	'
Premiums earned related to insurance business	656	645	1,309	1,311
Insurance underwriting income (loss)	$140	$96	$222	$191

Fair_Values_of_Financial_Instr2

Fair Values of Financial Instruments - Carrying Values and Fair Values of Financial Instruments (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Short Term Investments	$1,845	$2,114
Fixed maturities	38,062	37,091
Equity securities	1,969	1,810
Long Term Debt	3,300	3,300
Carrying Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Short Term Investments	1,845	2,114
Fixed maturities	38,062	37,091
Equity securities	1,969	1,810
Long Term Debt	3,300	3,300
Fair Value [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Short Term Investments	1,845	2,114
Fixed maturities	38,062	37,091
Equity securities	1,969	1,810
Long Term Debt	$3,989	$3,806

Fair_Values_of_Financial_Instr3

Fair Values of Financial Instruments - Additional Information (Detail)	Jun. 30, 2014	Dec. 31, 2013
Fair Value Disclosures [Abstract]	'	'
Percentage of fair value amounts for fixed maturities provided by a pricing service	99.00%	99.00%

Fair_Values_of_Financial_Instr4

Fair Values of Financial Instruments - Fair Value of Financial Instruments Categorized Based Upon Lowest Level of Input (Detail) (USD $)	Jun. 30, 2014	Dec. 31, 2013
In Millions, unless otherwise specified
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Short Term Investments	$1,845	$2,114
Tax exempt, Fair Value	19,220	18,421
Taxable, Fair Value	18,842	18,670
Total fixed maturities, Fair Value	38,062	37,091
Equity securities	1,969	1,810
Long Term Debt	3,300	3,300
Residential Mortgage Backed Securities [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	250	299
Commercial Mortgage Backed Securities [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	1,207	1,365
U.S. Government and Government Agency and Authority Obligations [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	1,286	802
Corporate Bonds [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	9,194	9,314
Foreign Government and Government Agency Obligations [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	6,905	6,890
Fair Value [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Short Term Investments	1,845	2,114
Tax exempt, Fair Value	19,220	18,421
Taxable, Fair Value	18,842	18,670
Total fixed maturities, Fair Value	38,062	37,091
Equity securities	1,969	1,810
Total fixed maturities, equity securities and other invested assets, Fair Value	41,876	41,015
Long Term Debt	3,989	3,806
Fair Value [Member] | U.S. Government and Government Agency and Authority Obligations [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	1,286	802
Fair Value [Member] | Corporate Bonds [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	9,194	9,314
Fair Value [Member] | Foreign Government and Government Agency Obligations [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	6,905	6,890
Residential Mortgage-backed Securities [Member] | Fair Value [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	250	299
Commercial Mortgage-backed Securities [Member] | Fair Value [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	1,207	1,365
Level 1 [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Short Term Investments	284	399
Equity securities	1,963	1,803
Total fixed maturities, equity securities and other invested assets, Fair Value	2,247	2,202
Long Term Debt	'	'
Level 1 [Member] | U.S. Government and Government Agency and Authority Obligations [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	'	'
Level 2 [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Short Term Investments	1,561	1,715
Tax exempt, Fair Value	19,216	18,416
Taxable, Fair Value	18,690	18,500
Total fixed maturities, Fair Value	37,906	36,916
Total fixed maturities, equity securities and other invested assets, Fair Value	39,467	38,631
Long Term Debt	3,989	3,806
Level 2 [Member] | U.S. Government and Government Agency and Authority Obligations [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	1,286	802
Level 2 [Member] | Corporate Bonds [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	9,066	9,179
Level 2 [Member] | Foreign Government and Government Agency Obligations [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	6,896	6,881
Level 2 [Member] | Residential Mortgage-backed Securities [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	246	293
Level 2 [Member] | Commercial Mortgage-backed Securities [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	1,196	1,345
Level 3 [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Tax exempt, Fair Value	4	5
Taxable, Fair Value	152	170
Total fixed maturities, Fair Value	156	175
Equity securities	6	7
Total fixed maturities, equity securities and other invested assets, Fair Value	162	182
Long Term Debt	'	'
Level 3 [Member] | U.S. Government and Government Agency and Authority Obligations [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	'	'
Level 3 [Member] | Corporate Bonds [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	128	135
Level 3 [Member] | Foreign Government and Government Agency Obligations [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	9	9
Level 3 [Member] | Residential Mortgage-backed Securities [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	4	6
Level 3 [Member] | Commercial Mortgage-backed Securities [Member]	'	'
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]	'	'
Taxable, Fair Value	$11	$20

Earnings_Per_Share_Computation

Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Detail) (USD $)	3 Months Ended		6 Months Ended
In Millions, except Per Share data, unless otherwise specified	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Basic earnings per share:	'	'	'	'
Net Income	$499	$579	$948	$1,235
Weighted average shares outstanding	245.7	260.5	247.1	261.9
Basic earnings per share	$2.03	$2.22	$3.84	$4.72
Diluted earnings per share:	'	'	'	'
Net Income	$499	$579	$948	$1,235
Weighted average shares outstanding	245.7	260.5	247.1	261.9
Additional shares from assumed issuance of shares under stock-based compensation awards	0.5	1	0.6	1.3
Weighted average shares and potential shares assumed outstanding for computing diluted earnings per share	246.2	261.5	247.7	263.2
Diluted earnings per share	$2.03	$2.21	$3.83	$4.69