Fair Value Measurements

12 Months Ended

Dec. 31, 2016

Fair Value Disclosures [Abstract]

Fair Value Measurements

9. FAIR VALUE MEASUREMENTS

The Fair Value Measurement Topic of the ASC establishes a framework for measuring fair value and disclosures about fair value measurements.

Fair Value Hierarchy:

The Fair Value Measurement Topic of the ASC specifies a fair value hierarchy based on whether the inputs to valuation techniques used to measure fair value are observable or unobservable. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect Company-based assumptions. The fair value hierarchy prioritizes model inputs into three broad levels as follows:

l	Level 1	Quoted prices for identical instruments in active markets. Assets and liabilities classified as Level 1 include US Treasury and other foreign government obligations traded in highly liquid and transparent markets, exchange traded futures contracts, variable rate demand obligations and money market funds.
l	Level 2	Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations in which all significant inputs and significant value drivers are observable in active markets. Assets and liabilities classified as Level 2 generally include direct investments in fixed income securities representing municipal, asset-backed and corporate obligations, most financial services derivatives, and most long-term debt of variable interest entities consolidated under the Consolidation Topic of the ASC.
l	Level 3	Model derived valuations in which one or more significant inputs or significant value drivers are unobservable. This hierarchy requires the use of observable market data when available. Assets and liabilities classified as Level 3 include credit derivative contracts written as part of the financial guarantee business, certain financial services interest rate swap contracts, equity interests in Ambac sponsored special purpose entities and certain investments in fixed income securities. Additionally, Level 3 assets and liabilities generally include fixed income securities, loan receivables, and certain long-term debt of variable interest entities consolidated under the Consolidation Topic of the ASC.

The following table sets forth the carrying amount and fair value of Ambac’s financial assets and liabilities as of December 31, 2016 and 2015, including the level within the fair value hierarchy at which fair value measurements are categorized. As required by the Fair Value Measurement Topic of the ASC financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement.

	Carrying Amount			Total Fair Value			Fair Value Measurements Categorized as:
							Level 1		Level 2			Level 3
December 31, 2016:
Financial assets:
Fixed income securities:
Municipal obligations	$	374,368		$	374,368		$	—	$	374,368		$	—
Corporate obligations	1,802,165			1,802,165			—		1,802,165			—
Foreign obligations	43,135			43,135			42,212		923			—
U.S. government obligations	36,186			36,186			36,186		—			—
U.S. agency obligations	4,060			4,060			—		4,060			—
Residential mortgage-backed securities	2,351,595			2,351,595			—		1,654,882			696,713
Collateralized debt obligations	113,923			113,923			—		113,923			—
Other asset-backed securities	828,783			828,783			—		762,793			65,990
Fixed income securities, pledged as collateral:
U.S. government obligations	64,905			64,905			64,905		—			—
Short term investments	430,788			430,788			371,367		59,421			—
Other investments (2)	450,307			435,237			83,791		—			14,934
Cash and cash equivalents	91,025			91,025			46,587		44,438			—
Loans	4,160			4,066			—		—			4,066
Derivative assets:
Interest rate swaps—asset position	77,206			77,206			—		16,950			60,256
Futures contracts	536			536			536		—			—
Other assets	7,382			7,382			—		—			7,382
Variable interest entity assets:
Fixed income securities:
Corporate obligations	2,622,566			2,622,566			—		—			2,622,566
Restricted cash	4,873			4,873			4,873		—			—
Loans	10,658,963			10,658,963			—		—			10,658,963
Derivative assets:
Currency swaps-asset position	80,407			80,407			—		80,407			—
Total financial assets	$	20,047,333		$	20,032,169		$	650,457	$	4,914,330		$	14,130,870
Financial liabilities:
Obligations under investment agreements	$	82,358		$	82,333		$	—	$	—		$	82,333
Long term debt, including accrued interest	1,536,352			1,494,340			—		1,147,728			346,612
Derivative liabilities:
Credit derivatives	15,349			15,349			—		—			15,349
Interest rate swaps—asset position	(61,839		)	(61,839		)	—		(61,839		)	—
Interest rate swaps—liability position	365,776			365,776			—		220,587			145,189
Liabilities for net financial guarantees written (1)	3,009,943			4,490,070			—		—			4,490,070
Variable interest entity liabilities:
Long-term debt	11,155,936			11,155,936			—		8,573,716			2,582,220
Derivative liabilities:
Interest rate swaps—liability position	2,078,601			2,078,601			—		2,078,601			—
Total financial liabilities	$	18,182,476		$	19,620,566		$	—	$	11,958,793		$	7,661,773

	Carrying Amount			Total Fair Value			Fair Value Measurements Categorized as:
							Level 1		Level 2			Level 3
December 31, 2015:
Financial assets:
Fixed income securities:
Municipal obligations	$	420,770		$	420,770		$	—	$	420,770		$	—
Corporate obligations	1,593,669			1,593,669			—		1,593,669			—
Foreign obligations	96,306			96,306			87,808		8,498			—
U.S. government obligations	26,687			26,687			26,687		—			—
U.S. agency obligations	4,212			4,212			—		4,212			—
Residential mortgage-backed securities	1,977,338			1,977,338			—		1,488,454			488,884
Collateralized debt obligations	84,267			84,267			—		84,267			—
Other asset-backed securities	840,527			840,527			—		840,527			—
Fixed income securities, pledged as collateral:
U.S. government obligations	64,555			64,555			64,555		—			—
Short term investments	225,789			225,789			197,398		28,391			—
Other investments (2)	310,600			298,095			45,745		—			12,834
Cash and cash equivalents	35,744			35,744			35,744		—			—
Loans	5,206			5,128			—		—			5,128
Derivative assets:
Interest rate swaps—asset position	84,886			84,886			—		21,848			63,038
Interest rate swaps—liability position	—			—			—		—			—
Futures contracts	109			109			109		—			—
Other assets	8,696			8,696			—		—			8,696
Variable interest entity assets:
Fixed income securities:
Corporate obligations	2,588,556			2,588,556			—		—			2,588,556
Restricted cash	5,822			5,822			5,822		—			—
Loans	11,690,324			11,690,324			—		—			11,690,324
Total financial assets	$	20,064,063		$	20,051,480		$	463,868	$	4,490,636		$	14,857,460
Financial liabilities:
Obligations under investment agreements	$	100,358		$	101,400		$	—	$	—		$	101,400
Long term debt, including accrued interest	1,481,045			1,235,721			—		132,837			1,102,884
Derivative liabilities:
Credit derivatives	34,543			34,543			—		—			34,543
Interest rate swaps—asset position	(52,128		)	(52,128		)	—		(52,128		)	—
Interest rate swaps—liability position	370,943			370,943			—		243,256			127,687
Liabilities for net financial guarantees written (1)	2,033,484			2,325,859			—		—			2,325,859
Variable interest entity liabilities:
Long-term debt	12,327,960			12,327,960			—		9,147,790			3,180,170
Derivative liabilities:
Interest rate swaps—liability position	1,965,265			1,965,265			—		1,965,265			—
Currency swaps—liability position	(36,862		)	(36,862		)	—		(36,862		)	—
Total financial liabilities	$	18,224,608		$	18,272,701		$	—	$	11,400,158		$	6,872,543

(1) The carrying value of net financial guarantees written includes the following balance sheet items: Premium receivables; Reinsurance recoverable on paid and unpaid losses; Deferred ceded premium; Subrogation recoverable; Insurance intangible asset; Unearned premiums; Loss and loss expense reserves; Ceded premiums payable, premiums taxes payable and other deferred fees recorded in Other liabilities.

(2) Excluded from the fair value measurement categories in the table above are investment funds of $336,513 and $239,516 as of December 31, 2016 and 2015, respectively, which are measured using NAV per share as a practical expedient.

Determination of Fair Value:

When available, Ambac uses quoted active market prices specific to the financial instrument to determine fair value, and classifies such items within Level 1. Because many fixed income securities do not trade on a daily basis, pricing sources apply available market information through processes such as matrix pricing to determine fair value. In those cases, the items are classified within Level 2. If quoted market prices are not available, fair value is based upon models that use, where possible, current market-based or independently-sourced market parameters. Items valued using valuation models are classified according to the lowest level input or value driver that is significant to the valuation. Thus, an item may be classified in Level 3 even though there may be significant inputs that are readily observable.

The determination of fair value for financial instruments categorized in Level 2 or 3 involves significant judgment due to the complexity of factors contributing to the valuation. Third-party sources from which we obtain independent market quotes also use assumptions, judgments and estimates in determining financial instrument values and different third parties may use different methodologies or provide different prices for securities. In addition, the use of internal valuation models may require assumptions about hypothetical or inactive markets. As a result of these factors, the actual trade value of a financial instrument in the market, or exit value of a financial instrument position by Ambac, may be significantly different from its recorded fair value.

Ambac’s financial instruments carried at fair value are comprised of investments in fixed income securities, equity interests in pooled investment funds, derivative instruments, variable interest entity assets and liabilities and equity interests in Ambac sponsored special purpose entities. Valuation of financial instruments is performed by Ambac’s finance group using methods approved by senior financial management with consultation from risk management and portfolio managers as appropriate. Preliminary valuation results are discussed with portfolio managers quarterly to assess consistency with market transactions and trends as applicable. Market transactions such as trades or negotiated settlements of similar positions, if any, are reviewed quarterly to validate fair value model results. However many of the financial instruments valued using significant unobservable inputs have very little or no observable market activity. Methods and significant inputs and assumptions used to determine fair values across portfolios are reviewed quarterly by senior financial management. Other valuation control procedures specific to particular portfolios are described further below.

We reflect Ambac’s own creditworthiness in the fair value of financial liabilities by including a credit valuation adjustment (“CVA”) in the determination of fair value. A decline (increase) in Ambac’s creditworthiness as perceived by market participants will generally result in a higher (lower) CVA, thereby lowering (increasing) the fair value of Ambac’s financial liabilities as reported.

Fixed Income Securities:

The fair values of fixed income investment securities are based primarily on market prices received from dealer quotes or alternative pricing sources with reasonable levels of price transparency. Such quotes generally consider a variety of factors, including recent trades of the same and similar securities. For those fixed income investments where quotes were not available or cannot be reasonably corroborated, fair values are based on internal valuation models. Key inputs to the internal valuation models generally include maturity date, coupon and yield curves for asset-type and credit rating characteristics that closely match those characteristics of the specific investment securities being valued. Longer (shorter) expected maturities or higher (lower) yields used in the valuation model will, in isolation, result in decreases (increases) in fair value. Generally, lower credit ratings or longer expected maturities will be accompanied by higher yields used to value a security. Certain investments in Ambac insured securities for which projected cash flows consist solely of Deferred Amounts and interest thereon, are internally valued based upon the valuation of Ambac Assurance's surplus notes. At December 31, 2016, approximately 5%, 82%, and 13% of the investment portfolio (excluding variable interest entity investments) was valued using dealer quotes, alternative pricing sources with reasonable levels of price transparency and internal valuation models, respectively. At December 31, 2015, approximately 9%, 82%, and 9% of the investment portfolio (excluding variable interest entity investments) was valued using dealer quotes, alternative pricing sources with reasonable levels of price transparency and internal valuation models, respectively.

Ambac performs various review and validation procedures to quoted and modeled prices for fixed income securities, including price variance analyses, missing and static price reviews, overall valuation analyses by senior traders and finance managers and reviews associated with our ongoing impairment analysis. Unusual prices identified through these procedures will be evaluated further against additional market data (if available) and/or internally modeled prices, and the pricing source values will be challenged as necessary. Price challenges generally result in the use of the pricing source’s quote as originally provided or as revised by the source following their internal diligence process. A price challenge may result in a determination by either the pricing source or Ambac management that the pricing source cannot provide a reasonable value for a security or cannot adequately support a quote, in which case Ambac would resort to using either other quotes or internal models. Results of price challenges are reviewed by senior traders and finance managers.

Information about the valuation inputs for fixed income securities classified as Level 3 is included below:

Residential mortgage-backed securities: These securities are guaranteed under policies that are subject to the Segregated Account Rehabilitation Plan and have projected future cash flows consisting solely of Deferred Amounts under such policies including interest thereon. The fair value of such securities classified as Level 3 was $696,713 and $488,884 at December 31, 2016 and 2015, respectively. Fair value was calculated based on the valuation of Ambac Assurance surplus notes which, under the terms of the Segregated Account Rehabilitation Plan, are to be redeemed in proportion with the payment of Deferred Amounts on or about the dates when such payments are made. Refer to Note 1. Background and Business Descriptionfor further description of the Segregated Account Rehabilitation Plan and its impact on the payment of Segregated Account policy claims and surplus note redemptions.

Other asset-backed securities: These securities are a subordinated tranche of a resecuritization collateralized by Ambac-insured military housing bonds. The fair value of such securities classified as Level 3 was $65,990 and $0 at December 31, 2016 and 2015, respectively. Fair value was calculated using a discounted cash flow approach with expected future cash flows discounted using a yield consistent with the security type and rating. Significant inputs for the valuation at December 31, 2016 include the following weighted averages:

a. Coupon rate:	5.93%
b. Average Life:	17.74 years
c. Yield:	13.5%

Other Investments:

Other investments primarily relate to investments in pooled investment funds. The fair value of pooled investment funds is determined using dealer quotes or alternative pricing sources when such investments have readily determinable fair values. When fair value is not readily determinable, pooled investment funds are valued using the net asset value (“NAV”) per share as a practical expedient as permitted under the Fair Value Measurement Topic of the ASC. Below is additional information about such investments in pooled funds that are reported at fair value using NAV as a practical expedient. There are no unfunded commitments applicable to any of these investments for the periods disclosed.

	Fair Value at December 31,
Class of Funds	2016		2015		Redemption Frequency	Redemption Notice Period
Real estate properties (1)	$	33,303	$	59,719	quarterly	10 business days
Diversified hedge fund strategies (2)	53,985		35,464		semi-monthly	15 - 30 days
Credit products (3)	210,157		99,579		daily, weekly or monthly	0 - 30 days
Illiquid investments (4)	39,068		44,754		quarterly	180 days

(1) Investments consist of UK property to generate income and capital growth.

(2) Investments seek diversified exposure to hedge fund core strategies to produce high risk-adjusted returns, with low long-term correlation to traditional markets and with targeted volatility levels. Funds may have the right to defer redemptions under certain circumstances.

(3) This class of funds includes investments in a range of instruments including leveraged loans, CLOs, asset-backed securities and floating rate notes to generate income and capital appreciation. Funds with less frequent redemption periods limit redemptions to as little as 15% per period. Funds with a same day redemption notice period are redeemable only weekly, while funds that may be redeemed any business day have notice periods of 15-30 days.

(4) This class seeks to obtain high long-term total return through investments with low liquidity and defined terms, resulting in expected capital distributions to subscribers between 2020 and 2023. Redemptions cannot occur prior to the expiration of the investment lock-up period in May 2018.

Other investments also includes Ambac's interest in a non-consolidated VIE, which is carried under the equity method. Valuation of this equity interest is internally calculated using a discounted cash flow approach and is classified as Level 3.

Derivative Instruments:

Ambac’s derivative instruments primarily comprise interest rate and credit default swaps, and exchange traded futures contracts. Fair value is determined based upon market quotes from independent sources, when available. For centrally cleared interest rate swaps, valuations are determined using quotes from the central counterparty. When independent quotes are not available, fair value is determined using valuation models. These valuation models require market-driven inputs, including contractual terms, credit spreads and ratings on underlying referenced obligations, yield curves and tax-exempt interest ratios. The valuation of certain interest rate as well as all credit derivative contracts also require the use of data inputs and assumptions that are determined by management and are not readily observable in the market. Under the Fair Value Measurement Topic of the ASC, Ambac is required to consider its own credit risk when measuring the fair value of derivative and other liabilities. The fair value of credit derivative liabilities was reduced by $1,924 and $10,124 at December 31, 2016 and 2015, as a result of incorporating a CVA into the valuation model for these transactions. Interest rate swaps and other derivative liabilities may also require an adjustment to fair value to reflect Ambac’s credit risk. Derivative liabilities were reduced by $44,943 and $78,728 at December 31, 2016 and 2015, as a result of Ambac CVA adjustments to derivative contracts other than credit derivatives. Additional factors considered in estimating the amount of any Ambac CVA on such contracts include collateral posting provisions, right of set-off with the counterparty, the period of time remaining on the derivatives and the pricing of recent terminations.

As described further below, certain valuation models require other inputs that are not readily observable in the market. The selection of a model to value a derivative depends on the contractual terms of, and specific risks inherent in the instrument as well as the availability of pricing information in the market.

Derivatives that are less complex may be valued primarily by reference to interest rates and yield curves that are observable and regularly quoted, such as interest rate swaps, we generally utilize vendor-developed models. These models provide the net present value of the derivatives based on contractual terms and observable market data. Downgrades of Ambac Assurance, as guarantor of the financial services derivatives, have increased collateral requirements and triggered termination provisions in certain interest rate swaps. Termination activity since the initial rating downgrades of Ambac Assurance provided additional information about the replacement and/or exit value of certain financial services derivatives, which has been incorporated into the fair value of these derivatives as appropriate. Generally, the need for counterparty (or Ambac) CVAs is mitigated by the existence of collateral posting agreements under which adequate collateral has been posted. Derivative contracts entered into with financial guarantee customers are not typically subject to collateral posting agreements. Counterparty credit risk related to such customer derivative assets is included in our fair value adjustments.

For derivatives that do not trade, or trade in less liquid markets such as credit derivatives, an internal model is generally used because such instruments tend to be unique, contain complex or heavily modified and negotiated terms, and pricing information is not readily available in the market. Derivative fair value models and the related assumptions are continuously re-evaluated by management and enhanced, as appropriate, based on improvements in modeling techniques. Ambac has not made any significant changes to its modeling techniques or related model inputs for the periods presented.

Credit Derivatives (“CDS”):

Fair value of Ambac’s CDS is determined using internal valuation models and represents the net present value of the difference between the fees Ambac originally charged for the credit protection and our estimate of what a financial guarantor of comparable credit quality would hypothetically charge to provide the same protection at the balance sheet date. Ambac competed in the financial guarantee market, which differs from the credit markets where Ambac-insured obligations may trade. As a financial guarantor, Ambac assumes only credit risk; we do not assume other risks and costs inherent in direct ownership of the underlying reference securities. Additionally, as a result of having the ability to influence our CDS counterparty in certain investor decisions, financial guarantors generally have the ability to actively remediate the credit, potentially reducing the loss given a default. Financial guarantee contracts, including CDS, issued by Ambac and its competitors are typically priced to capture some portion of the spread that would be observed in the capital markets for the underlying (insured) obligation. Such pricing was well established by historical financial guarantee fees relative to capital market spreads as observed and executed in competitive markets, including in financial guarantee reinsurance and secondary market transactions. Because of this relationship and in the absence of severe credit deterioration, changes in the fair value of our credit default swaps will generally be less than changes in the fair value of the underlying reference obligations.

Key variables used in our valuation of substantially all of our credit derivatives include the balance of unpaid notional, expected term, fair values of the underlying reference obligations, reference obligation credit ratings, assumptions about current financial guarantee CDS fee levels relative to reference obligation spreads and the CVA applied against Ambac Assurance liabilities by market participants. Notional balances, expected remaining term and reference obligation credit ratings are monitored or determined by Ambac’s Portfolio Risk Management group. Fair values of the underlying reference obligations are obtained from broker quotes when available, or are estimated internally. Implicit in the fair values we obtain on the underlying reference obligations are the market’s assumptions about default probabilities, default timing, correlation, recovery rates and collateral values.

Fair values of reference obligations named in our CDS contracts are an input to determine the estimated fair value of the CDS and are determined using the same methodologies used to value Ambac’s fixed income securities in its investment portfolio as described above. CDS reference obligation fair values are based on market prices received from dealer quotes or alternative pricing sources with reasonable levels of price transparency. When quotes for reference obligations are not available or cannot be reasonably corroborated, reference obligation prices used in the valuation model are estimated internally based on available market prices or spreads for securities or indices with similar characteristics such as underlying collateral, credit rating and expected life. Internal estimates may also consider historical quotes on the reference obligation, updated for changes in market factors and security specific developments such as credit rating changes. Reference obligation prices derived internally as described above were used in the determination of CDS fair values related to transactions representing 0% of CDS gross par outstanding and 0% of the CDS derivative liability as of December 31, 2016.

Ambac’s CDS fair value calculations are adjusted for changes in our estimates of expected loss on the reference obligations and observable changes in financial guarantee market pricing. If no adjustment is considered necessary, Ambac maintains the same percentage of the credit spread (over LIBOR) demanded in the market for the reference obligation as existed at the inception of the CDS. Therefore, absent changes in expected loss on the reference obligations or financial guarantee CDS market pricing, the financial guarantee CDS fee used for a particular contract in Ambac’s fair value calculations represent a consistent percentage, period to period, of the credit spread determinable from the reference obligation value at the balance sheet date. This results in a CDS fair value balance that fluctuates in proportion with the reference obligation value.

The amount of expected loss on a reference obligation is a function of the probability that the obligation will default and severity of loss in the event of default. Ambac’s CDS transactions were all originally underwritten with extremely low expected losses. Both the reference obligation spreads and Ambac’s CDS fees at the inception of these transactions reflected these low expected losses. When reference obligations experience credit deterioration, there is an increase in the probability of default on the obligation and, therefore, an increase in expected loss. Ambac reflects the effects of changes in expected loss on the fair value of its CDS contracts by increasing the percentage of the reference obligation spread (over LIBOR) which would be captured as a CDS fee (“relative change ratio”) at the valuation date, resulting in a higher mark-to-market loss on our CDS relative to any price decline on the reference obligation. The fundamental assumption is that financial guarantee CDS fees will increase relative to reference obligation spreads as the underlying credit quality of the reference obligation deteriorates and approaches payment default. For example, if the credit spread of an underlying reference obligation was 80 basis points at the inception of a transaction and Ambac received a 20 basis point fee for issuing a CDS on that obligation, the relative change ratio, which represents the CDS fee to cash market spread Ambac would utilize in its valuation calculation, would be 25%. If the reference obligation spread increased to 100 basis points in the current reporting period, absent any observable changes in financial guarantee CDS market pricing or credit deterioration, Ambac’s current period CDS fee would be computed by multiplying the current reference obligation spread of 100 basis points by the relative change ratio of 25%, resulting in a 25 basis point fee. Thus, the model indicates we would need to receive an additional 5 basis points (25 basis points currently less the 20 basis points contractually received) for issuing a CDS in the current reporting period for this reference obligation. We would then discount the product of the notional amount of the CDS and the 5 basis point hypothetical CDS fee increase, over the weighted average life of the reference obligation to compute the current period mark-to-market loss. Using the same example, if the reference obligation spread increased to 100 basis points and there was credit deterioration as evidenced by an internal rating downgrade which increased the relative change ratio from 25% to 35%, we would estimate a 15 basis point CDS fee increase in our model (35% of 100 basis points reference obligation spread, or 35 basis points currently, less the 20 basis points contractually received). Therefore, we would record a higher mark-to-market loss based on the computations described above absent any observable changes in financial guarantee CDS market pricing.

We do not adjust the relative change ratio until an actual internal rating downgrade has occurred unless we observe new pricing on financial guarantee CDS contracts. Since we have active surveillance procedures in place for our entire CDS portfolio, particularly for transactions at or near a below investment grade threshold, we believe it is unlikely that an internal downgrade would lag the actual credit deterioration of a transaction for any meaningful time period. The factors used to increase the relative change ratio are based on rating agency probability of default percentages determined by management to be appropriate for the relevant bond type. That is, the probability of default associated with the respective tenor and internal rating of each CDS transaction is utilized in the computation of the relative change ratio in our CDS valuation model. The new relative change ratio in the event of an internal downgrade of the reference obligation is calculated as the weighted average of: (i) a given transaction’s inception relative change ratio and (ii) a ratio of 100%. The weight given to the inception relative change ratio is 100% minus the current probability of default (the probability of non-default) and the weight given to using a 100% relative change ratio is the probability of default. For example, assume a transaction having an inception relative change ratio of 33% is downgraded to B-during the period, at which time it has an estimated remaining life of 8 years. If the estimated probability of default for an 8 year, B-rated credit of this type is 60% then the revised relative change ratio will be 73.2%. The revised relative change ratio can be calculated as 33% x (100%-60%) +100% x 60% = 73.2%.

As noted above, reference obligation spreads incorporate market perceptions of default probability and loss severity, as well as liquidity risk and other factors. By increasing the relative change ratio in our calculations proportionally to default probabilities, Ambac incorporates into its CDS fair value the higher expected loss on the reference obligation (probability of default x loss severity), by increasing the portion of reference obligation spread that should be paid to the CDS provider.

Ambac incorporates its own credit risk into the valuation of its CDS liabilities by applying a CVA to the calculations described above. Under our methodology, determination of the CDS fair value requires estimating hypothetical financial guarantee CDS fees for a given credit at the valuation date and estimating the present value of those fees. Our approach begins with pricing in the risk of default of the reference obligation using that obligation’s credit spread. The widening of the reference obligation spread results in a mark-to-market loss to Ambac, as the credit protection seller, and a gain to the credit protection buyer because the current cost of credit protection on the reference obligation (ignoring CDS counterparty credit risk) will be greater than the amount of the actual contractual CDS fees. The Ambac CVA represents the difference between the present value of the hypothetical fees discounted at LIBOR compared to rates that incorporate Ambac credit risk. The discount rates used to determine the Ambac CVA are estimated using relevant data points, including quoted prices of securities guaranteed by Ambac Assurance which indicate the value placed by market participants on Ambac Assurance’s insurance obligations and the fair value of Ambac Assurance surplus notes. The resulting Ambac CVA, as a percentage of the CDS mark-to-market liability determined by discounting at LIBOR, was 11.1% and 22.7% as of December 31, 2016 and 2015, respectively. In instances where narrower reference obligation spreads result in a CDS asset to Ambac, those hypothetical future CDS fees are discounted at a rate which incorporates our counterparty’s credit spread (i.e. the discount rate used is LIBOR plus the current credit spread of the counterparty).

In addition, when there are sufficient numbers of new observable transactions, negotiated settlements or other market indications of a general change in market pricing trends for CDS on a given bond type, management will adjust its assumptions about the percentage of reference obligation spreads captured as CDS fees to match the current market. No such adjustments were made during the periods presented. Ambac is not transacting CDS business currently and other guarantors have stated they have exited this product. Additionally, there have been no negotiated settlements of CDS contracts during the periods presented.

Key variables which impact the “Realized gains and losses and other settlements” component of “Net change in fair value of credit derivatives” in the Consolidated Statements of Total Comprehensive Income are the most readily observable variables since they are based solely on the CDS contractual terms and cash settlements. Those variables include premiums received and accrued and losses paid and payable on written credit derivative contracts for the appropriate accounting period. Losses paid and payable reported in “Realized gains and losses and other settlements” include those arising after a credit event that requires a payment under the contract terms has occurred or in connection with a negotiated termination of a contract. The remaining key variables described above impact the “Unrealized gains (losses)” component of “Net change in fair value of credit derivatives.”

The net notional outstanding of Ambac’s CDS contracts were $737,380 and $970,883 at December 31, 2016 and 2015, respectively. Credit derivative liabilities at December 31, 2016 and 2015 had a combined fair value of $15,349 and $34,543, respectively, and related to underlying reference obligations that are classified as either collateralized loan obligations (“CLOs”) or Other. Information about the above described model inputs used to determine the fair value of each class of credit derivatives, including the CVA as a percentage of the gross mark-to-market liability before considering Ambac credit risk (“CVA percentage”), as of December 31, 2016 and 2015 is summarized below:

	2016						2015
December 31,	CLOs			Other			CLOs			Other (1)
Notional outstanding	$	123,052		$	614,328		$	295,253		$	617,148
Weighted average reference obligation price	99.5			92.3			98.4			85.2
Weighted average life (WAL) in years	1.8			5.9			1.1			6.1
Weighted average credit rating	AA			A-			AA			BBB+
Weighted average relative change ratio	36.6		%	30.6		%	36.3		%	33.3		%
CVA percentage	7.47		%	11.19		%	8.34		%	23.34		%
Fair value of derivative liabilities	$	213		$	15,136		$	1,837		$	32,697

(1) Excludes contracts for which fair values are based on credit derivative quotes rather than reference obligation quotes. As of December 31, 2015, these contracts had a combined notional outstanding of $58,482, WAL of 0.2 years and liability fair value of $9. Other inputs to the valuation of these transactions at December 31, 2015 include weighted average quotes of less than 1% of notional, weighted average rating of A+ and Ambac CVA percentage of 0.09%.

Significant unobservable inputs for credit derivatives include WAL, internal credit rating, relative change ratio and CVA percentage. A longer (shorter) WAL, lower (higher) reference obligation credit rating, higher (lower) relative change ratio or lower (higher) CVA, in isolation, would result in an increase (decrease) in the fair value liability measurement. A change in an internal credit rating of a reference obligation in our model will generally result in a directionally opposite change in the relative change ratio. Also, a shorter (longer) WAL will generally correspond with a lower (higher) CVA percentage.

Financial Guarantees:

Fair value of net financial guarantees written represents our estimate of the cost to Ambac to completely transfer its insurance obligation to another market participant of comparable credit worthiness. In theory, this amount should be the same amount that another market participant of comparable credit worthiness would hypothetically charge in the market place, on a present value basis, to provide the same protection as of the balance sheet date. This fair value estimate of financial guarantees is presented on a net basis and includes direct and assumed contracts written, net of ceded reinsurance contracts.

The fair value estimate of financial guarantees is computed by utilizing cash flows calculated at the policy level. For direct and assumed contracts, net cash flows for each policy included: (i) installment premium receipts, (ii) estimated future gross claim payments, (iii) subrogation receipts, and (iv) unpaid claims on claims presented and not yet paid for policies allocated to the Segregated Account, including Deferred Amounts and interest thereon. The timing of future claim payments of the Segregated Account are at the sole discretion of the Rehabilitator. For ceded reinsurance contracts, net cash flows for each policy included: (i) installment ceded premium payments, (ii) ceding commission receipts, (iii) ceded claim receipts, and (iv) ceded subrogation payments. For each direct, assumed, and ceded reinsurance contract, the respective undiscounted cash flow components are aggregated to determine if we are in a net asset or net liability position. U.S. GAAP requires that the nonperformance risk of a financial liability be included in the estimation of fair value, which includes considering Ambac Assurance’s own credit risk. Accordingly, for each contract in a net liability position, we estimate the fair value using internally developed discount rates and market pricing that incorporate Ambac’s own credit risk and subsequently apply a profit margin. This profit margin represents what another market participant would require to assume the financial guarantee contracts. Given the unique nature of financial guarantees there is a lack of observable market information to make this estimate. A profit margin was developed based on discussions with the third-party institutions with valuation expertise, discussions with industry participants and yields on Ambac Assurance surplus notes. The profit margin is applied to the present value of contracts in a net liability position. The discount rates used for contracts in a net liability position are derived from guaranteed securities with future cash flows that are highly dependent upon Ambac financial guarantee payments as well as the rates implicit in the fair value of Ambac Assurance's surplus notes, as applicable. For each contract in a net asset position, we estimate the fair value using a discount rate that is commensurate with a hypothetical buyer’s cost of capital.

This methodology is based on management’s expectations of how a market participant would estimate net cash flows. We are aware of a number of factors that may cause such fair or exit value to differ, perhaps materially. For example, (i) since no financial guarantor with Ambac’s credit quality is writing new financial guarantee business we do not have access to observable pricing data points; (ii) although the fair value accounting guidance for liabilities requires a company to consider the cost to completely transfer its obligation to another party of comparable credit worthiness, our primary insurance obligation is irrevocable and thus there is no established active market for transferring such obligations; and (iii) certain segments of Ambac's financial guarantees have been allocated to the Segregated Account and timing of the payments of such liabilities are at the sole discretion of the Rehabilitator.

Long-term Debt:

The fair values of surplus notes issued by Ambac Assurance and the Segregated Account and classified as long-term debt is based on market prices received from dealer quotes or alternative pricing sources with reasonable levels of price transparency, when available. The fair values of surplus notes for which quotes are not available or cannot be reasonably corroborated are internally estimated considering market transactions when available and internally developed discounted cash flow models. Notes outstanding to third parties arising from Ambac Assurance's secured borrowing transaction are classified as long-term debt and valued using market prices received from dealer quotes.

Other Financial Assets and Liabilities:

The fair values of Ambac’s equity interest in Ambac sponsored special purpose entities (included in Other assets), Loans, and Obligations under investment agreements are estimated based upon internal valuation models that discount expected cash flows using discount rates consistent with the credit quality of the obligor after considering collateralization.

Variable Interest Entity Assets and Liabilities:

The financial assets and liabilities of VIEs consolidated under the Consolidation Topic of the ASC consist primarily of fixed income securities, loans, derivative and debt instruments and are generally carried at fair value. These consolidated VIEs are securitization entities which have liabilities and/or assets guaranteed by Ambac Assurance. The fair values of VIE debt instruments are determined using the same methodologies used to value Ambac’s fixed income securities in its investment portfolio as described above. VIE debt fair value is based on market prices received from dealer quotes or alternative pricing sources with reasonable levels of price transparency. Such quotes are considered Level 2 and generally consider a variety of factors, including recent trades of the same and similar securities. For those VIE debt instruments where quotes were not available, the debt instrument fair values are considered Level 3 and are based on internal discounted cash flow models. Comparable to the sensitivities of investments in fixed income securities described above, longer (shorter) expected maturities or higher (lower) yields used in the valuation model will, in isolation, result in decreases (increases) in fair value liability measurement for VIE debt. VIE debt instruments considered Level 3 include fixed rate, floating rate and zero coupon notes secured by various asset types, primarily European ABS. Information about the valuation inputs for the various VIE debt categories classified as Level 3 is as follows:

European ABS transactions: The fair value of such obligations classified as Level 3 was $2,551,278 and $3,016,966 at December 31, 2016 and 2015, respectively. Fair values were calculated by using a discounted cash flow approach. The discount rates used were based on the rates implied from the third party quoted values for comparable notes from the same securitization entity. Significant inputs for the valuation at December 31, 2016 and 2015 include the following weighted averages:

December 31, 2016		December 31, 2015
a. Coupon rate:	0.46%	a. Coupon rate:	1.38%
b. Maturity:	16.16 years	b. Maturity:	16.44 years
c. Yield:	4.95%	c. Yield:	6.08%

US Commercial ABS transaction: The fair value of such obligations classified as Level 3 was $30,942 and $163,204 at December 31, 2016 and 2015, respectively. Fair values were calculated as the sum of the present value of expected future cash flows from the underlying VIE assets plus the present value of the related Ambac financial guarantee cash flows. The discount rates applied to cash flows sourced from VIE assets were based on interest rates for similar obligations. The fair value of financial guarantee cash flows include internal estimates of future loss payments by Ambac discounted at a rate that incorporates Ambac’s own credit risk. Significant inputs for the valuation at December 31, 2016 and 2015, include the following weighted averages:

December 31, 2016		December 31, 2015
a. Coupon rate:	5.88%	a. Coupon rate:	5.88%
b. Maturity:	20.85 years	b. Maturity:	21.81 years
c. Yield:	5.86%	c. Yield:	9.14%

VIE derivative asset and liability fair values are determined using valuation models. When specific derivative contractual terms are available and may be valued primarily by reference to interest rates, foreign exchange rates and yield curves that are observable and regularly quoted, the derivatives are valued using vendor-developed models. Other derivatives within the VIEs that include significant unobservable valuation inputs are valued using internally developed models. VIE derivative fair value balances at December 31, 2016 and 2015 were developed using vendor-developed models and do not use significant unobservable inputs.

The fair value of VIE assets are obtained from market quotes when available. Typically the asset fair values are not readily available from market quotes and are estimated internally. The consolidated VIEs are securitization entities in which net cash flows from assets and derivatives (after adjusting for financial guarantor cash flows and other expenses) will be paid out to note holders or equity interests. Our valuation of VIE assets (fixed income securities or loans), therefore, are generally derived from the fair value of notes and derivatives, as described above, adjusted for the fair value of cash flows from Ambac’s financial guarantee. The fair value of financial guarantee cash flows include: (i) estimated future premiums discounted at a rate consistent with that implicit in the fair value of the VIE’s liabilities and (ii) internal estimates of future loss payments by Ambac discounted at a rate that includes Ambac’s own credit risk. Estimated future premium payments to be paid by the VIEs were discounted at a weighted average rate of 3.6% and 4.4% at December 31, 2016 and 2015, respectively. The value of future loss payments to be paid by Ambac to the VIEs was adjusted to include an Ambac CVA appropriate for the term of expected Ambac claim payments.

Additional Fair Value Information:

The following tables present the changes in the Level 3 fair value category for the periods presented in 2016 and 2015. Ambac classifies financial instruments in Level 3 of the fair value hierarchy when there is reliance on at least one significant unobservable input to the valuation model. In addition to these unobservable inputs, the valuation models for Level 3 financial instruments typically also rely on a number of inputs that are readily observable either directly or indirectly. Thus, the gains and losses presented below include changes in the fair value related to both observable and unobservable inputs.

Level-3 Financial Assets and Liabilities Accounted for at Fair Value

										VIE Assets and Liabilities
Year Ended December 31, 2016	Investments			Other Assets			Derivatives			Investments			Loans			Long-term Debt			Total
Balance, beginning of period	$	488,884		$	8,696		$	(99,192	)	$	2,588,556		$	11,690,324		$	(3,180,170	)	$	11,497,098
Total gains/(losses) realized and unrealized:
Included in earnings	54,600			(1,314		)	(15,374		)	508,873			1,166,898			(842,748		)	870,935
Included in other comprehensive income	40,518			—			—			(474,863		)	(1,944,821		)	486,218			(1,892,948		)
Purchases	99,018			—			—			—			—			—			99,018
Issuances	—			—			—			—			—			—			—
Sales	—			—			—			—			—			—			—
Settlements	(28,682		)	—			14,284			—			(253,438		)	216,582			(51,254		)
Transfers into Level 3	108,365			—			—			—			—			—			108,365
Transfers out of Level 3	—			—			—			—			—			737,898			737,898
Deconsolidation of VIEs	—			—			—			—			—			—			—
Balance, end of period	$	762,703		$	7,382		$	(100,282	)	$	2,622,566		$	10,658,963		$	(2,582,220	)	$	11,369,112
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date	$	—		$	(1,314	)	$	(16,351	)	$	508,873		$	1,166,898		$	(842,748	)	$	815,358

										VIE Assets and Liabilities
Year Ended December 31, 2015	Investments			Other Assets			Derivatives			Investments			Loans			Long-term Debt			Total
Balance, beginning of period	$	198,201		$	12,036		$	(215,346	)	$	2,743,050		$	12,371,177		$	(1,263,664	)	$	13,845,454
Total gains/(losses) realized and unrealized:
Included in earnings	30,083			(1,635		)	16,571			(7,263		)	569,617			(1,152,681		)	(545,308		)
Included in other comprehensive income	(73,559		)	—			—			(147,231		)	(612,941		)	93,812			(739,919		)
Purchases	359,193			—			—			—			—			—			359,193
Issuances	—			—			—			—			—			—			—
Sales	—			—			—			—			—			—			—
Settlements	(25,034		)	(1,705		)	11,365			—			(312,406		)	(17,085		)	(344,865		)
Transfers into Level 3	—			—			88,218			—			—			(840,552		)	(752,334		)
Transfers out of Level 3	—			—			—			—			—			—			—
Deconsolidations of VIEs	—			—			—			—			(325,123		)	—			(325,123		)
Balance, end of period	$	488,884		$	8,696		$	(99,192	)	$	2,588,556		$	11,690,324		$	(3,180,170	)	$	11,497,098
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date	$	—		$	(1,635	)	$	(25,980	)	$	(7,263	)	$	589,634		$	(1,161,991	)	$	(607,235	)

										VIE Assets and Liabilities
Year Ended December 31, 2014	Investments			Other Assets			Derivatives			Investments			Loans			Long-term Debt			Total
Balance, beginning of period	$	67,783		$	13,384		$	(186,934	)	$	2,475,182		$	13,398,895		$	(1,514,605	)	$	14,253,705
Total gains/(losses) realized and unrealized:
Included in earnings	11,057			(1,348		)	(45,392		)	429,113			1,118,084			(290,457		)	1,221,057
Included in other comprehensive income	(541		)	—			—			(161,245		)	(726,827		)	66,515			(822,098		)
Purchases	54,013			—			—			—			70,000			—			124,013
Issuances	—			—			—			—			—			—			—
Sales	(59,878		)	—			—			—			—			—			(59,878		)
Settlements	(62,266		)	—			16,980			—			(792,186		)	433,896			(403,576		)
Transfers into Level 3	188,241			—			—			—			—			—			188,241
Transfers out of Level 3	(208		)	—			—			—			—			4,096			3,888
Deconsolidation of VIEs	—			—			—			—			(696,789		)	36,891			(659,898		)
Balance, end of period	$	198,201		$	12,036		$	(215,346	)	$	2,743,050		$	12,371,177		$	(1,263,664	)	$	13,845,454
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date	$	—		$	(1,348	)	$	(53,509	)	$	429,113		$	1,119,219		$	(286,405	)	$	1,207,070

The tables below provide roll-forward information by class of investments and derivatives measured using significant unobservable inputs.

Level-3 Investments by Class

Year Ended December 31, 2016	Other Asset Backed Securities			Non-Agency RMBS			Total Investments
Balance, beginning of period	$	—		$	488,884		$	488,884
Total gains/(losses) realized and unrealized:
Included in earnings	1,908			52,692			54,600
Included in other comprehensive income	(5,597		)	46,115			40,518
Purchases	—			99,018			99,018
Issuances	—			—			—
Sales	—			—			—
Settlements	(1,028		)	(27,654		)	(28,682		)
Transfers into Level 3	70,707			37,658			108,365
Transfers out of Level 3	—			—			—
Balance, end of period	$	65,990		$	696,713		$	762,703
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date	$	—		$	—		$	—

Year Ended December 31, 2015	Corporate Obligations			Non-Agency RMBS			Total Investments
Balance, beginning of period	$	3,808		$	194,393		$	198,201
Total gains/(losses) realized and unrealized:
Included in earnings	(19		)	30,102			30,083
Included in other comprehensive income	(286		)	(73,273		)	(73,559		)
Purchases	—			359,193			359,193
Issuances	—			—			—
Sales	—			—			—
Settlements	(3,503		)	(21,531		)	(25,034		)
Transfers into Level 3	—			—			—
Transfers out of Level 3	—			—			—
Balance, end of period	$	—		$	488,884		$	488,884
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date	$	—		$	—		$	—

Year Ended December 31, 2014	Other Asset Backed Securities			Corporate Obligations			U.S. Agency Obligations			Non-Agency RMBS			Total Investments
Balance, beginning of period	$	64,073		$	3,502		$	208		$	—		$	67,783
Total gains/(losses) realized and unrealized:
Included in earnings	6,994			(97		)	—			4,160			11,057
Included in other comprehensive income	(8,182		)	403			—			7,238			(541		)
Purchases	—			—			—			54,013			54,013
Issuances	—			—			—			—			—
Sales	(59,878		)	—			—			—			(59,878		)
Settlements	(3,007		)	—			—			(59,259		)	(62,266		)
Transfers into Level 3	—			—			—			188,241			188,241
Transfers out of Level 3	—			—			(208		)	—			(208		)
Balance, end of period	$	—		$	3,808		$	—		$	194,393		$	198,201
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date	$	—		$	—		$	—		$	—		$	—

Level-3 Derivatives by Class

	2016									2015
Year Ended December 31,	Interest Rate Swaps			Credit Derivatives			Total Derivatives			Interest Rate Swaps			Credit Derivatives			Total Derivatives
Balance, beginning of period	$	(64,649	)	$	(34,543	)	$	(99,192	)	$	(141,887	)	$	(73,459	)	$	(215,346	)
Total gains/(losses) realized and unrealized:
Included in earnings	(35,480		)	20,106			(15,374		)	(25,130		)	41,701			16,571
Included in other comprehensive income	—			—			—			—			—			—
Purchases	—			—			—			—			—			—
Issuances	—			—			—			—			—			—
Sales	—			—			—			—			—			—
Settlements	15,196			(912		)	14,284			14,150			(2,785		)	11,365
Transfers into Level 3	—			—			—			88,218			—			88,218
Transfers out of Level 3	—			—			—			—			—			—
Balance, end of period	$	(84,933	)	$	(15,349	)	$	(100,282	)	$	(64,649	)	$	(34,543	)	$	(99,192	)
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date	$	(35,480	)	$	19,129		$	(16,351	)	$	(25,130	)	$	(850	)	$	(25,980	)

	2014
Year Ended December 31,	Interest Rate Swaps			Credit Derivatives			Total Derivatives
Balance, beginning of period	$	(92,612	)	$	(94,322	)	$	(186,934	)
Total gains/(losses) realized and unrealized:
Included in earnings	(69,298		)	23,906			(45,392		)
Included in other comprehensive income	—			—			—
Purchases	—			—			—
Issuances	—			—			—
Sales	—			—			—
Settlements	20,023			(3,043		)	16,980
Transfers into Level 3	—			—			—
Transfers out of Level 3	—			—			—
Balance, end of period	$	(141,887	)	$	(73,459	)	$	(215,346	)
The amount of total gains/(losses) included in earnings attributable to the change in unrealized gains or losses relating to assets and liabilities still held at the reporting date	$	(69,298	)	$	15,789		$	(53,509	)

Invested assets and VIE long-term debt are transferred into Level 3 when internal valuation models that include significant unobservable inputs are used to estimate fair value. All such securities that have internally modeled fair values have been classified as Level 3. Other Asset-backed securities transferred into Level 3 in 2016 consist of a subordinated tranche of a resecuritization collateralized by Ambac-insured military housing bonds. Non-agency RMBS transferred into Level 3 in 2014 and 2016 consist of certain investments in Ambac-wrapped RMBS securities for which projected cash flows consist solely of Deferred Amounts and interest thereon. These invested assets were internally valued as management could not corroborate the reasonableness of third party quotes. Derivative instruments are transferred into Level 3 when the use of unobservable inputs becomes significant to the overall valuation. Derivative instruments transferred into Level 3 in 2015 consisted of certain interest rate swap assets with counterparty credit adjustments. All transfers into and out of Level 3 represent transfers between Level 3 and Level 2. There were no transfers between Level 1 and Level 2 for the periods presented. All transfers between fair value hierarchy Levels 1, 2, and 3 are recognized at the beginning of each accounting period.

Gains and losses (realized and unrealized) relating to Level 3 assets and liabilities included in earnings for the affected periods are reported as follows:

	Net Investment Income		Realized Gains or (Losses) and Other Settlements on Credit Derivative Contracts		Unrealized Gains or (Losses) on Credit Derivative Contracts			Derivative Products Revenues (Interest Rate Swaps)			Income (Loss) on Variable Interest Entities			Other Income or (Loss)
Year Ended December 31, 2016
Total gains or losses included in earnings for the period	54,600		912		19,194			(35,480		)	833,023			(1,314		)
Changes in unrealized gains or losses relating to the assets and liabilities still held at the reporting date	—		—		19,129			(35,480		)	833,023			(1,314		)
Year Ended December 31, 2015
Total gains or losses included in earnings for the period	$	30,083	$	2,785	$	38,916		$	(25,130	)	$	(590,327	)	$	(1,635	)
Changes in unrealized gains or losses relating to the assets and liabilities still held at the reporting date	—		—		(850		)	(25,130		)	(579,620		)	(1,635		)
Year Ended December 31, 2014
Total gains or losses included in earnings for the period	$	11,057	$	3,043	$	20,863		$	(69,298	)	$	1,256,740		$	(1,348	)
Changes in unrealized gains or losses relating to the assets and liabilities still held at the reporting date	—		—		15,789			(69,298		)	1,261,927			(1,348		)