XML 95 R75.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Fair Value Measurements - Summary of Carrying Amount and Fair Value of Ambac's Financial Assets and Liabilities (Detail) - USD ($) | Dec. 31, 2018 | Dec. 31, 2017
--- | --- | ---
Financial assets: |  |
Debt Securities, Available-for-sale | $ 3,546,006,000 |
Short term investments | 430,331,000 | $ 557,270,000
Other Investments | 391,217,000 | 431,630,000
Derivative assets | 59,768,000 | 73,826,000
Other assets | 4,516,000 | 5,979,000
Financial liabilities: |  |
Derivative liabilities | 76,999,000 | 83,409,000
Variable Interest Entity [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 2,737,286,000 | 2,914,145,000
Loans at Carrying Amount | 4,287,664,000 | 11,529,384,000
Derivative assets | 66,302,000 | 54,877,000
Financial liabilities: |  |
Derivative liabilities | 1,712,062,000 | 2,205,264,000
Short-term Investments [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 430,331,000 | 557,270,000
Available-for-sale Securities | 430,331,000 |
Corporate Debt Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 2,737,286,000 | 2,914,145,000
Carrying Amount [Member] |  |
Financial assets: |  |
Loans | 9,913,000 | 10,358,000
Other assets | 4,516,000 | 5,979,000
Total financial assets | 11,185,865,000 | 20,953,414,000
Financial liabilities: |  |
Liabilities for net financial guarantees written | (718,388,000) | 3,435,438,000
Long-term debt | 3,304,737,000 | 1,428,680,000
Total financial liabilities | 9,643,706,000 | 19,312,708,000
Carrying Amount [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Restricted cash | 999,000 | 978,000
Loans at Carrying Amount | 4,287,664,000 | 11,529,384,000
Financial liabilities: |  |
Long-term debt | 5,268,596,000 | 12,160,544,000
Carrying Amount [Member] | Other Debt Obligations [Member] |  |
Financial assets: |  |
Other Investments | 391,217,000 | 431,630,000
Carrying Amount [Member] | Short-term Investments [Member] |  |
Financial assets: |  |
Short term investments | 430,331,000 | 557,270,000
Carrying Amount [Member] | Other Credit Derivatives [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 1,459,000 | 566,000
Carrying Amount [Member] | Corporate Debt Securities [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 2,737,286,000 | 2,914,145,000
Carrying Amount [Member] | Interest Rate Swaps [Member] |  |
Financial liabilities: |  |
Derivative liabilities - interest rate swaps - asset position |  | 627,000
Derivative liabilities | 71,861,000 | 81,495,000
Carrying Amount [Member] | Interest Rate Swaps [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 1,712,062,000 | 2,205,264,000
Carrying Amount [Member] | Futures Contracts [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 3,379,000 | 1,348,000
Other Assets [Member] | Carrying Amount [Member] | Interest Rate Swaps [Member] |  |
Financial assets: |  |
Derivative assets | 59,468,000 | 73,199,000
Interest Rate Swaps - Liability Position [Member] | Carrying Amount [Member] | Currency Swaps [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Derivative assets | 66,302,000 | 54,877,000
Fair Value Measured at Net Asset Value Per Share [Member] |  |
Financial assets: |  |
Other Investments | 279,941,000 | 310,441,000
Level 1 [Member] |  |
Financial assets: |  |
Total financial assets | 553,964,000 | 1,273,040,000
Financial liabilities: |  |
Liabilities for net financial guarantees written | 0 | 0
Long-term debt | 0 | 0
Total financial liabilities | 3,379,000 | 1,348,000
Level 1 [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Restricted cash | 999,000 | 978,000
Loans | 0 | 0
Financial liabilities: |  |
Long-term debt | 0 | 0
Level 1 [Member] | Other Debt Obligations [Member] |  |
Financial assets: |  |
Other Investments | 71,108,000 | 56,498,000
Level 1 [Member] | Short-term Investments [Member] |  |
Financial assets: |  |
Short term investments | 304,880,000 | 389,299,000
Level 1 [Member] | Equity Method Investments [Member] |  |
Financial assets: |  |
Other assets | 0 | 0
Level 1 [Member] | Other Credit Derivatives [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 0 | 0
Level 1 [Member] | Corporate Debt Securities [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 0 | 0
Level 1 [Member] | Interest Rate Swaps [Member] |  |
Financial liabilities: |  |
Derivative liabilities - interest rate swaps - asset position |  | 0
Derivative liabilities | 0 | 0
Level 1 [Member] | Interest Rate Swaps [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 0 | 0
Level 1 [Member] | Futures Contracts [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 3,379,000 | 1,348,000
Level 1 [Member] | Loans Receivable [Member] |  |
Financial assets: |  |
Loans | 0 | 0
Level 1 [Member] | Other Assets [Member] | Interest Rate Swaps [Member] |  |
Financial assets: |  |
Derivative assets | 0 | 0
Level 1 [Member] | Interest Rate Swaps - Liability Position [Member] | Currency Swaps [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Derivative assets | 0 | 0
Level 2 [Member] |  |
Financial assets: |  |
Total financial assets | 3,152,882,000 | 4,005,195,000
Financial liabilities: |  |
Liabilities for net financial guarantees written | 0 | 0
Long-term debt | 2,909,272,000 | 1,046,511,000
Total financial liabilities | 9,744,699,000 | 12,735,499,000
Level 2 [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Restricted cash | 0 | 0
Loans | 0 | 0
Financial liabilities: |  |
Long-term debt | 5,051,504,000 | 9,402,856,000
Level 2 [Member] | Other Debt Obligations [Member] |  |
Financial assets: |  |
Other Investments | 0 | 29,750,000
Level 2 [Member] | Short-term Investments [Member] |  |
Financial assets: |  |
Short term investments | 125,451,000 | 167,971,000
Level 2 [Member] | Equity Method Investments [Member] |  |
Financial assets: |  |
Other assets | 0 | 0
Level 2 [Member] | Other Credit Derivatives [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 0 | 0
Level 2 [Member] | Corporate Debt Securities [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 0 | 0
Level 2 [Member] | Interest Rate Swaps [Member] |  |
Financial liabilities: |  |
Derivative liabilities - interest rate swaps - asset position |  | 627,000
Derivative liabilities | 71,861,000 | 81,495,000
Level 2 [Member] | Interest Rate Swaps [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 1,712,062,000 | 2,205,264,000
Level 2 [Member] | Futures Contracts [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 0 | 0
Level 2 [Member] | Loans Receivable [Member] |  |
Financial assets: |  |
Loans | 0 | 0
Level 2 [Member] | Other Assets [Member] | Interest Rate Swaps [Member] |  |
Financial assets: |  |
Derivative assets | 12,008,000 | 11,825,000
Level 2 [Member] | Interest Rate Swaps - Liability Position [Member] | Currency Swaps [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Derivative assets | 66,302,000 | 54,877,000
Level 3 [Member] |  |
Financial assets: |  |
Total financial assets | 7,176,883,000 | 15,347,011,000
Financial liabilities: |  |
Liabilities for net financial guarantees written | 558,824,000 | 4,842,402,000
Long-term debt | 350,694,000 | 322,988,000
Total financial liabilities | 1,128,069,000 | 7,923,644,000
Level 3 [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Restricted cash | 0 | 0
Loans | 4,287,664,000 | 11,529,384,000
Financial liabilities: |  |
Long-term debt | 217,092,000 | 2,757,688,000
Level 3 [Member] | Other Debt Obligations [Member] |  |
Financial assets: |  |
Other Investments | 16,266,000 | 17,288,000
Level 3 [Member] | Short-term Investments [Member] |  |
Financial assets: |  |
Short term investments | 0 | 0
Level 3 [Member] | Equity Method Investments [Member] |  |
Financial assets: |  |
Other assets | 4,516,000 | 5,979,000
Level 3 [Member] | Other Credit Derivatives [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 1,459,000 | 566,000
Level 3 [Member] | Corporate Debt Securities [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 2,737,286,000 | 2,914,145,000
Level 3 [Member] | Interest Rate Swaps [Member] |  |
Financial liabilities: |  |
Derivative liabilities - interest rate swaps - asset position |  | 0
Derivative liabilities | 0 | 0
Level 3 [Member] | Interest Rate Swaps [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 0 | 0
Level 3 [Member] | Futures Contracts [Member] |  |
Financial liabilities: |  |
Derivative liabilities |  | 0
Level 3 [Member] | Loans Receivable [Member] |  |
Financial assets: |  |
Loans | 11,620,000 | 10,284,000
Level 3 [Member] | Other Assets [Member] | Interest Rate Swaps [Member] |  |
Financial assets: |  |
Derivative assets | 47,460,000 | 61,374,000
Level 3 [Member] | Interest Rate Swaps - Liability Position [Member] | Currency Swaps [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Derivative assets | 0 | 0
Ambac insured Re-remic [Member] | Level 3 [Member] |  |
Financial assets: |  |
Available-for-sale Securities |  | 26,067,000
Municipal Bonds [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 879,919,000 | 779,834,000
Corporate Debt Securities [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 1,278,122,000 | 860,075,000
Debt Security, Government, Non-US [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 30,834,000 | 26,543,000
US Government Debt Securities [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 94,394,000 | 85,408,000
Residential Mortgage-Backed Securities [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 258,607,000 | 2,251,333,000
Collateralized Debt Obligations [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 131,356,000 | 51,037,000
Asset-backed Securities [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 442,443,000 | 597,942,000
Cash and Cash Equivalents [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Cash | 82,494,000 | 623,703,000
Cash and Cash Equivalents [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Cash | 82,494,000 | 623,703,000
Cash and Cash Equivalents [Member] | Level 1 [Member] |  |
Financial assets: |  |
Cash | 52,661,000 | 615,073,000
Cash and Cash Equivalents [Member] | Level 2 [Member] |  |
Financial assets: |  |
Cash | 29,833,000 | 8,630,000
Cash and Cash Equivalents [Member] | Level 3 [Member] |  |
Financial assets: |  |
Cash | 0 | 0
Fair Value, Measurements, Recurring [Member] |  |
Financial assets: |  |
Total financial assets | 11,163,670,000 | 20,935,687,000
Financial liabilities: |  |
Liabilities for net financial guarantees written | 558,824,000 | 4,842,402,000
Long-term debt | 3,259,966,000 | 1,369,499,000
Total financial liabilities | 10,876,147,000 | 20,660,491,000
Fair Value, Measurements, Recurring [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Restricted cash | 999,000 | 978,000
Loans | 4,287,664,000 | 11,529,384,000
Financial liabilities: |  |
Long-term debt | 5,268,596,000 | 12,160,544,000
Fair Value, Measurements, Recurring [Member] | Other Debt Obligations [Member] |  |
Financial assets: |  |
Other Investments | 367,315,000 | 413,977,000
Fair Value, Measurements, Recurring [Member] | Short-term Investments [Member] |  |
Financial assets: |  |
Short term investments | 430,331,000 | 557,270,000
Fair Value, Measurements, Recurring [Member] | Equity Method Investments [Member] |  |
Financial assets: |  |
Other assets | 4,516,000 | 5,979,000
Fair Value, Measurements, Recurring [Member] | Other Credit Derivatives [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 1,459,000 | 566,000
Fair Value, Measurements, Recurring [Member] | Asset-backed Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 442,443,000 | 597,942,000
Fair Value, Measurements, Recurring [Member] | Collateralized Debt Obligations [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 131,356,000 | 51,037,000
Fair Value, Measurements, Recurring [Member] | Residential Mortgage-Backed Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 258,607,000 | 2,251,333,000
Fair Value, Measurements, Recurring [Member] | US Government Debt Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 94,394,000 | 85,408,000
Fair Value, Measurements, Recurring [Member] | Debt Security, Government, Non-US [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 30,834,000 | 26,543,000
Fair Value, Measurements, Recurring [Member] | Corporate Debt Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 1,278,122,000 | 860,075,000
Fair Value, Measurements, Recurring [Member] | Corporate Debt Securities [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 2,737,286,000 | 2,914,145,000
Fair Value, Measurements, Recurring [Member] | Municipal Bonds [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 879,919,000 | 779,834,000
Fair Value, Measurements, Recurring [Member] | Interest Rate Swaps [Member] |  |
Financial liabilities: |  |
Derivative liabilities - interest rate swaps - asset position |  | 627,000
Derivative liabilities | 71,861,000 | 81,495,000
Fair Value, Measurements, Recurring [Member] | Interest Rate Swaps [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 1,712,062,000 | 2,205,264,000
Fair Value, Measurements, Recurring [Member] | Futures Contracts [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 3,379,000 | 1,348,000
Fair Value, Measurements, Recurring [Member] | Loans Receivable [Member] |  |
Financial assets: |  |
Loans | 11,620,000 | 10,284,000
Fair Value, Measurements, Recurring [Member] | Other Assets [Member] | Interest Rate Swaps [Member] |  |
Financial assets: |  |
Derivative assets | 59,468,000 | 73,199,000
Fair Value, Measurements, Recurring [Member] | Interest Rate Swaps - Liability Position [Member] | Currency Swaps [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Derivative assets | 66,302,000 | 54,877,000
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Asset-backed Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 0 | 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Collateralized Debt Obligations [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 0 | 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Residential Mortgage-Backed Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 0 | 0
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | US Government Debt Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 94,394,000 | 85,408,000
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Debt Security, Government, Non-US [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 29,922,000 | 25,615,000
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Corporate Debt Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 0 | 450,000
Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | Municipal Bonds [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 0 | 0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Asset-backed Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 370,372,000 | 525,402,000
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Collateralized Debt Obligations [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 131,356,000 | 51,037,000
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Residential Mortgage-Backed Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 258,607,000 | 1,515,316,000
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | US Government Debt Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 0 | 0
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Debt Security, Government, Non-US [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 912,000 | 928,000
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Corporate Debt Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 1,278,122,000 | 859,625,000
Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | Municipal Bonds [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 879,919,000 | 779,834,000
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Asset-backed Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 72,071,000 | 72,540,000
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Collateralized Debt Obligations [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 0 | 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Residential Mortgage-Backed Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 0 | 736,017,000
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | US Government Debt Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 0 | 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Debt Security, Government, Non-US [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 0 | 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Corporate Debt Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | 0 | 0
Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | Municipal Bonds [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale | $ 0 | 0
Collateral Pledged [Member] | US Government Debt Securities [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale |  | 99,719,000
Collateral Pledged [Member] | Fair Value, Measurements, Recurring [Member] | US Government Debt Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale |  | 99,719,000
Collateral Pledged [Member] | Fair Value, Measurements, Recurring [Member] | Level 1 [Member] | US Government Debt Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale |  | 99,719,000
Collateral Pledged [Member] | Fair Value, Measurements, Recurring [Member] | Level 2 [Member] | US Government Debt Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale |  | 0
Collateral Pledged [Member] | Fair Value, Measurements, Recurring [Member] | Level 3 [Member] | US Government Debt Securities [Member] |  |
Financial assets: |  |
Debt Securities, Available-for-sale |  | $ 0

X
- Definition Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258 + Details
Name: | us-gaap_AssetsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale). + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=109979856&loc=d3e26610-111562 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesDebtSecurities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References No definition available. + Details
Name: | us-gaap_CashAndCashEquivalentsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, before effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets elected not to be offset. Excludes assets not subject to a master netting arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226000-175313 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4D -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=109247956&loc=SL51823488-111719 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624163-113959 + Details
Name: | us-gaap_DerivativeFairValueOfDerivativeAsset
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value, before effects of master netting arrangements, of a financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes liabilities elected not to be offset. Excludes liabilities not subject to a master netting arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4D -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=109247956&loc=SL51823488-111719 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624163-113959 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226000-175313 + Details
Name: | us-gaap_DerivativeFairValueOfDerivativeLiability
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value of asset associated with financial liability or contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=51824906&loc=SL20225862-175312 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=99393222&loc=SL20226003-175313 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -URI http://asc.fasb.org/extlink&oid=109980867&loc=SL5624163-113959 + Details
Name: | us-gaap_DerivativeLiabilityFairValueGrossAsset
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of investments accounted under the equity method. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 25 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=66022186&loc=d3e32014-111567 + Details
Name: | us-gaap_EquityMethodInvestmentsFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- References No definition available. + Details
Name: | us-gaap_FinancialInstrumentsFinancialAssetsBalanceSheetGroupingsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_FinancialInstrumentsFinancialLiabilitiesBalanceSheetGroupingsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair value portion of guarantee, including, but not limited to, financial standby letter of credit, fair value guarantee, guarantee of collection of scheduled contractual cash flows from financial assets, and contracts that contingently require the guarantor to make payments or perform services. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=115931803&loc=d3e12201-110248 + Details
Name: | us-gaap_GuaranteesFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value of financial and nonfinancial obligations. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=99377789&loc=d3e19207-110258 + Details
Name: | us-gaap_LiabilitiesFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value portion of loan receivable, including, but not limited to, mortgage loans held for investment, finance receivables held for investment, policy loans on insurance contracts. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -URI http://asc.fasb.org/subtopic&trid=2196772 + Details
Name: | us-gaap_LoansReceivableFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount after allowance and deduction of deferred interest and fees, unamortized costs and premiums and discounts from face amounts, of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes loans held for sale. Excludes loans and leases covered under loss sharing agreements. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.7(a)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_LoansReceivableNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. + References No definition available. + Details
Name: | us-gaap_LongTermDebtFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of investments classified as other. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.1(f,g)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.12) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_OtherInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of short-term investments classified as other. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03.1(g)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.8) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03.5) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
Name: | us-gaap_OtherShortTermInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of cash and cash equivalents restricted as to withdrawal or usage, classified as current. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section 45 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=82887183&loc=d3e6676-107765 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3044-108585 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 50 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=98513485&loc=SL98516268-108586 + Details
Name: | us-gaap_RestrictedCashAndCashEquivalentsAtCarryingValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_VariableInterestEntitiesByClassificationOfEntityAxis=us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_ShortTermInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_CarryingReportedAmountFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_OtherDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_OtherCreditDerivativesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_InterestRateSwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_FutureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_OtherAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BalanceSheetLocationAxis=us-gaap_OtherLiabilitiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CurrencySwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueMeasuredAtNetAssetValuePerShareMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel1Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_EquityMethodInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_LoansReceivableMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel2Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByFairValueHierarchyLevelAxis=us-gaap_FairValueInputsLevel3Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=ambc_AmbacinsuredReremicMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_MunicipalBondsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_ForeignGovernmentDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_USGovernmentDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_ResidentialMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_CollateralizedDebtObligationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CashAndCashEquivalentsAxis=us-gaap_CashAndCashEquivalentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementBasisAxis=us-gaap_EstimateOfFairValueFairValueDisclosureMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByMeasurementFrequencyAxis=us-gaap_FairValueMeasurementsRecurringMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_AssetBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_CollateralizedDebtObligationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_ResidentialMortgageBackedSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_USGovernmentDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_ForeignGovernmentDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FinancialInstrumentAxis=us-gaap_MunicipalBondsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_CollateralAxis=us-gaap_CollateralPledgedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |