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 and option 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. At December 31, 2017, we held no positions in option contracts on equity market indices. 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. In general, the base lapse function assumes low lapse rates (ranging from about 3 percent to 9 percent per annum) during the surrender charge period of the GMIB contract, followed by a “spike” lapse rate (ranging from about 6 percent to 33 percent per annum) in the year immediately following the surrender charge period, and then reverting to an ultimate lapse rate (generally around 10 percent per annum), typically over a 2-year period. This base rate is adjusted downward for policies with more valuable guarantees (policies with guaranteed values far in excess of their account values) by multiplying the base lapse rate by a factor ranging from 15 percent to 75 percent. Partial withdrawals and the impact of older policyholders with tax-qualified contracts (due to required minimum distributions) are also reflected in our modeling.

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. All GMIB reinsurance treaties include claim limits to protect Chubb in the event that actual annuitization behavior is significantly higher than expected. In general, Chubb assumes that GMIB annuitization rates will be higher for policies with more valuable guarantees (policies with guaranteed values far in excess of their account values). In addition, we also assume that GMIB annuitization rates are higher in the first year immediately following the waiting period (the first year the policies are eligible to annuitize using the GMIB) in comparison to all subsequent years. We do not yet have fully credible annuitization experience for all clients.

The level of annuitization assumptions at December 31, 2017 are as follows:



% of total GMIB guaranteed value	Year of GMIB eligibility	Maximum annuitization rate(s) (per year)	Maximum annuitization rates based on
67%	First year	2% - 52%	Actual Experience
67%	Subsequent years	1% - 100%	Actual Experience
3%	First year	N/A	N/A⁽¹⁾
3%	Subsequent years	12%, 100%	Weighted average⁽²⁾
30%	First year	25%, 56%	Weighted average⁽²⁾
30%	Subsequent years	12%, 36%	Weighted average⁽²⁾

⁽¹⁾Because all policies in this bracket are past the first year of eligibility, first year annuitization assumptions are no longer modeled.

⁽²⁾Weighted average of two different annuitization rates.

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.

In the fourth quarter of 2017, we completed a review of policyholder behavior related to annuitizations, partial withdrawals, lapses, and mortality for our variable annuity reinsurance business.


•	As annuitization experience continued to emerge, we refined our annuitization assumptions including age-based behavior, which generally lowered the annuitization rate. The change in annuitization assumptions decreased the fair value of GLB liabilities and generated a realized gain of approximately $117 million.

•

Reinsured policies allow for policyholders to make periodic withdrawals from their account values without lapsing the policy. The partial withdrawal results in a reduction to the associated guaranteed value that is either equal or proportional to the amount of the reduction in account value. Based on continued emerging experience, we refined our assumptions around the types of partial withdrawals according to their impact on guaranteed value. This resulted in an increase to the fair value of GLB liabilities generating a realized loss of approximately $43 million.


•	As lapse experience continued to emerge, we further refined our assumptions which resulted in a net increase to the fair value of GLB liabilities generating a realized loss of approximately $9 million.


•	We studied mortality experience for our variable annuity business for the first time this year and subsequently refined our mortality assumptions. The updated mortality rates increased the fair value of GLB liabilities generating a realized loss of approximately $25 million.

In addition to the updates described above, we updated aspects of our valuation model relating to interest rates during the year ended December 31, 2017. This resulted in a decrease to the fair value of GLB liabilities generating a realized gain of approximately $94 million.

During the year ended December 31, 2017, we also made minor technical refinements to the internal valuation model which resulted in no material impact on the financial statements.

Financial instruments measured at fair value on a recurring basis, by valuation hierarchy



December 31, 2017	Level 1		Level 2		Level 3		Total
(in millions of U.S. dollars)	Level 1		Level 2		Level 3		Total
Assets:
Fixed maturities available for sale
U.S. Treasury and agency	$	3,129	$	569	$	—	$	3,698
Foreign	—		20,937		93		21,030
Corporate securities	—		22,959		1,037		23,996
Mortgage-backed securities	—		15,212		78		15,290
States, municipalities, and political subdivisions	—		14,925		—		14,925
	3,129		74,602		1,208		78,939
Equity securities	893		—		44		937
Short-term investments	2,309		1,252		—		3,561
Other investments ⁽¹⁾	466		305		263		1,034
Securities lending collateral	—		1,737		—		1,737
Investment derivative instruments	18		—		—		18
Other derivative instruments	1		—		—		1
Separate account assets	2,635		99		—		2,734
Total assets measured at fair value ⁽¹⁾	$	9,451	$	77,995	$	1,515	$	88,961
Liabilities:
Investment derivative instruments	$	30	$	—	$	—	$	30
Other derivative instruments	21		—		2		23
GLB ⁽²⁾	—		—		204		204
Total liabilities measured at fair value	$	51	$	—	$	206	$	257


⁽¹⁾	Excluded from the table above are partially-owned investments, investment funds, and limited partnerships of $3,623 million and other investments of $15 million at December 31, 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. Refer to Note 5 c) for additional information.



December 31, 2016	Level 1		Level 2		Level 3		Total
(in millions of U.S. dollars)	Level 1		Level 2		Level 3		Total
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. Refer to Note 5 c) for additional information.

There were no transfers of financial instruments between Level 1 and Level 2 for the years ended December 31, 2017, 2016, and 2015.

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:



		December 31				December 31
		2017				2016
(in millions of U.S. dollars)	Expected Liquidation Period of Underlying Assets	Fair Value		Maximum Future Funding Commitments		Fair Value		Maximum Future Funding Commitments
Financial	5 to 9 Years	$	540	$	330	$	548	$	428
Real Assets	3 to 7 Years	651		114		536		230
Distressed	3 to 7 Years	289		141		485		179
Private Credit	3 to 7 Years	187		327		236		259
Traditional	3 to 15 Years	1,656		3,149		1,550		930
Vintage	1 to 2 Years	30		—		21		14
Investment funds	Not Applicable	270		—		251		—
		$	3,623	$	4,061	$	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 or 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 at December 31, 2017		Valuation Technique	Significant Unobservable Inputs	Ranges
GLB⁽¹⁾	$	204	Actuarial model	Lapse rate	3% – 33%
				Annuitization rate	0% – 100%


⁽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
	Available-for-Sale Debt Securities									Equity securities			Short-term investments			Other investments			Other derivative instruments			GLB⁽²⁾
Year Ended December 31, 2017	Foreign			Corporate securities ⁽¹⁾			MBS
(in millions of U.S. dollars)	Foreign			Corporate securities ⁽¹⁾			MBS
Balance, beginning of year	$	74		$	681		$	45		$	41		$	25		$	225		$	13		$	559
Transfers into Level 3	—			231			50			—			—			—			—			9
Transfers out of Level 3	(3		)	(93		)	—			—			—			—			(9		)	—
Change in Net Unrealized Gains (Losses) included in OCI	3			(12		)	—			(1		)	—			6			—			—
Net Realized Gains/Losses	—			—			—			2			—			—			(2		)	(364		)
Purchases	84			521			8			24			16			56			—			—
Sales	(59		)	(111		)	(1		)	(22		)	—			—			—			—
Settlements	(6		)	(180		)	(24		)	—			(41		)	(24		)	—			—
Balance, end of year	$	93		$	1,037		$	78		$	44		$	—		$	263		$	2		$	204
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date	$	(1	)	$	(2	)	$	—		$	(1	)	$	—		$	—		$	(2	)	$	(364	)


⁽¹⁾	Transfers into and Purchases in Level 3 primarily consist of privately-placed fixed income securities.


⁽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. Refer to Note 5 c) for additional information.



																						Liabilities
	Available-for-Sale Debt Securities									Equity securities			Short-term investments			Other investments				Other derivative instruments		GLB⁽¹⁾
Year Ended December 31, 2016	Foreign			Corporate securities			MBS
(in millions of U.S. dollars)	Foreign			Corporate securities			MBS
Balance, beginning of year	$	57		$	174		$	53		$	16		$	—		$	212		—	$	6	$	609
Transfers into Level 3	9			53			—			—			—			—			—	—		—
Transfers out of Level 3	(24		)	(10		)	—			—			(50		)	—				—		—
Change in Net Unrealized Gains (Losses) included in OCI	1			15			(1		)	2			—			(2		)		—		—
Net Realized Gains/Losses	(6		)	(13		)	—			1			—			1				5		(50		)
Purchases⁽²⁾	70			566			1			27			75			33				2		—
Sales	(17		)	(59		)	(8		)	(5		)	—			—				—		—
Settlements	(16		)	(45		)	—			—			—			(19		)		—		—
Balance, end of year	$	74		$	681		$	45		$	41		$	25		$	225			$	13	$	559
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date	$	(5	)	$	(11	)	$	—		$	—		$	—		$	1			$	5	$	(50	)

⁽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 $853 million at December 31, 2016 and $888 million at December 31, 2015, which includes a fair value derivative adjustment of $559 million and $609 million, respectively.

⁽²⁾ Includes acquired invested assets as a result of the Chubb Corp acquisition.



	Assets															Liabilities
	Available-for-Sale Debt Securities															Other derivative instruments		GLB⁽¹⁾
Year Ended December 31, 2015	Foreign			Corporate securities			MBS			Equity securities			Other investments
(in millions of U.S. dollars)	Foreign			Corporate securities			MBS			Equity securities			Other investments
Balance, beginning of year	$	22		$	187		$	15		$	2		$	204		$	4	$	406
Transfers into Level 3	34			16			—			—			—			—		—
Transfers out of Level 3	—			—			—			—			—			—		—
Change in Net Unrealized Gains (Losses) included in OCI	(2		)	(1		)	—			3			(6		)	—		—
Net Realized Gains/Losses	(1		)	(4		)	—			(2		)	—			2		203
Purchases	15			52			41			13			33			—		—
Sales	(3		)	(28		)	(2		)	—			—			—		—
Settlements	(8		)	(48		)	(1		)				(19		)	—
Balance, end of year	$	57		$	174		$	53		$	16		$	212		$	6	$	609
Net Realized Gains/Losses Attributable to Changes in Fair Value at the Balance Sheet Date	$	(1	)	$	(2	)	$	—		$	(2	)	$	—		$	2	$	203

⁽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 $888 million at December 31, 2015 and $663 million at December 31, 2014, which includes a fair value derivative adjustment of $609 million and $406 million, respectively.

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:



December 31, 2017	Fair Value								Carrying Value
(in millions of U.S. dollars)	Level 1		Level 2		Level 3		Total		Carrying Value
Assets:
Fixed maturities held to maturity
U.S. Treasury and agency	$	857	$	58	$	—	$	915	$	908
Foreign	—		1,757		—		1,757		1,738
Corporate securities	—		3,184		35		3,219		3,159
Mortgage-backed securities	—		2,742		—		2,742		2,724
States, municipalities, and political subdivisions	—		5,841		—		5,841		5,806
Total assets	$	857	$	13,582	$	35	$	14,474	$	14,335
Liabilities:
Repurchase agreements	$	—	$	1,408	$	—	$	1,408	$	1,408
Short-term debt	—		1,013		—		1,013		1,013
Long-term debt	—		12,332		—		12,332		11,556
Trust preferred securities	—		468		—		468		308
Total liabilities	$	—	$	15,221	$	—	$	15,221	$	14,285



December 31, 2016	Fair Value								Carrying Value
(in millions of U.S. dollars)	Level 1		Level 2		Level 3		Total		Carrying Value
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