XML 62 R51.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Fair Value Measurements - Summary of Carrying Amount and Fair Value of Ambac's Financial Assets and Liabilities (Detail) - USD ($) $ in Thousands | Jun. 30, 2016 | Dec. 31, 2015
--- | --- | ---
Financial assets: |  |
Other investments | $ 383,107 | $ 285,261
Other assets | 8,687 | 8,696
Financial liabilities: |  |
Derivative liabilities | 18,207 | 34,543
Successor [Member] |  |
Financial assets: |  |
Fixed income securities | 6,110,754 | 5,334,120
Short term investments | 336,222 | 225,789
Successor [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Other investments | 394,273 | 298,095
Cash | 23,044 | 35,744
Loans | 4,464 | 5,128
Total financial assets | 20,303,101 | 20,051,480
Financial liabilities: |  |
Obligations under investment and repurchase agreements | 82,682 | 101,400
Liabilities for net financial guarantees written | 3,873,330 | 2,325,859
Long-term debt | 1,374,646 | 1,235,721
Total financial liabilities | 19,273,591 | 18,272,701
Successor [Member] | Total Fair Value [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Restricted cash | 5,461 | 5,822
Loans | 11,074,772 | 11,690,324
Financial liabilities: |  |
Long-term debt | 11,444,892 | 12,327,960
Successor [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Other investments | 410,727 | 310,600
Cash | 23,044 | 35,744
Loans | 4,615 | 5,206
Total financial assets | 20,319,706 | 20,064,063
Financial liabilities: |  |
Obligations under investment and repurchase agreements | 82,358 | 100,358
Liabilities for net financial guarantees written | 2,911,854 | 2,033,484
Long-term debt | 1,493,020 | 1,481,045
Total financial liabilities | 18,430,165 | 18,224,608
Successor [Member] | Carrying Amount [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Restricted cash | 5,461 | 5,822
Loans | 11,074,772 | 11,690,324
Financial liabilities: |  |
Long-term debt | 11,444,892 | 12,327,960
Successor [Member] | Investments Measured at NAV as a Practical Expedient [Member] |  |
Financial assets: |  |
Other investments | 333,448 | 239,516
Successor [Member] | Level 1 [Member] |  |
Financial assets: |  |
Other investments | 49,659 | 45,745
Cash | 23,044 | 35,744
Loans | 0 | 0
Total financial assets | 569,597 | 463,868
Financial liabilities: |  |
Obligations under investment and repurchase agreements | 0 | 0
Liabilities for net financial guarantees written | 0 | 0
Long-term debt | 0 | 0
Total financial liabilities | 1,356 | 0
Successor [Member] | Level 1 [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Restricted cash | 5,461 | 5,822
Loans | 0 | 0
Financial liabilities: |  |
Long-term debt | 0 | 0
Successor [Member] | Level 2 [Member] |  |
Financial assets: |  |
Other investments | 0 | 0
Cash | 0 | 0
Loans | 0 | 0
Total financial assets | 4,920,082 | 4,490,636
Financial liabilities: |  |
Obligations under investment and repurchase agreements | 0 | 0
Liabilities for net financial guarantees written | 0 | 0
Long-term debt | 1,093,436 | 132,837
Total financial liabilities | 12,592,050 | 11,400,158
Successor [Member] | Level 2 [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Restricted cash | 0 | 0
Loans | 0 | 0
Financial liabilities: |  |
Long-term debt | 9,186,883 | 9,147,790
Successor [Member] | Level 3 [Member] |  |
Financial assets: |  |
Other investments | 11,166 | 12,834
Cash | 0 | 0
Loans | 4,464 | 5,128
Total financial assets | 14,479,974 | 14,857,460
Financial liabilities: |  |
Obligations under investment and repurchase agreements | 82,682 | 101,400
Liabilities for net financial guarantees written | 3,873,330 | 2,325,859
Long-term debt | 281,210 | 1,102,884
Total financial liabilities | 6,680,185 | 6,872,543
Successor [Member] | Level 3 [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Restricted cash | 0 | 0
Loans | 11,074,772 | 11,690,324
Financial liabilities: |  |
Long-term debt | 2,258,009 | 3,180,170
Successor [Member] | Level 3 [Member] | Currency Swaps [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 0 |
Successor [Member] | Interest Rate Swaps [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Derivative assets | 104,353 | 84,886
Successor [Member] | Interest Rate Swaps [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Derivative assets | 104,353 | 84,886
Successor [Member] | Interest Rate Swaps [Member] | Level 1 [Member] |  |
Financial assets: |  |
Derivative assets | 0 | 0
Successor [Member] | Interest Rate Swaps [Member] | Level 2 [Member] |  |
Financial assets: |  |
Derivative assets | 23,431 | 21,848
Successor [Member] | Interest Rate Swaps [Member] | Level 3 [Member] |  |
Financial assets: |  |
Derivative assets | 80,922 | 63,038
Successor [Member] | Municipal Bonds [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Fixed income securities | 375,652 | 420,770
Successor [Member] | Municipal Bonds [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Fixed income securities | 375,652 | 420,770
Successor [Member] | Municipal Bonds [Member] | Level 1 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 | 0
Successor [Member] | Municipal Bonds [Member] | Level 2 [Member] |  |
Financial assets: |  |
Fixed income securities | 375,652 | 420,770
Successor [Member] | Municipal Bonds [Member] | Level 3 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 | 0
Successor [Member] | Corporate Obligations [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Fixed income securities | 1,730,703 | 1,593,669
Successor [Member] | Corporate Obligations [Member] | Total Fair Value [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Fixed income securities | 2,577,293 | 2,588,556
Successor [Member] | Corporate Obligations [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Fixed income securities | 1,730,703 | 1,593,669
Successor [Member] | Corporate Obligations [Member] | Carrying Amount [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Fixed income securities | 2,577,293 | 2,588,556
Successor [Member] | Corporate Obligations [Member] | Level 1 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 | 0
Successor [Member] | Corporate Obligations [Member] | Level 1 [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Fixed income securities | 0 | 0
Successor [Member] | Corporate Obligations [Member] | Level 2 [Member] |  |
Financial assets: |  |
Fixed income securities | 1,730,703 | 1,593,669
Successor [Member] | Corporate Obligations [Member] | Level 2 [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Fixed income securities | 0 | 0
Successor [Member] | Corporate Obligations [Member] | Level 3 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 | 0
Successor [Member] | Corporate Obligations [Member] | Level 3 [Member] | Variable Interest Entity [Member] |  |
Financial assets: |  |
Fixed income securities | 2,577,293 | 2,588,556
Successor [Member] | Foreign Obligations [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Fixed income securities | 75,390 | 96,306
Successor [Member] | Foreign Obligations [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Fixed income securities | 75,390 | 96,306
Successor [Member] | Foreign Obligations [Member] | Level 1 [Member] |  |
Financial assets: |  |
Fixed income securities | 60,649 | 87,808
Successor [Member] | Foreign Obligations [Member] | Level 2 [Member] |  |
Financial assets: |  |
Fixed income securities | 14,741 | 8,498
Successor [Member] | Foreign Obligations [Member] | Level 3 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 | 0
Successor [Member] | US Government Debt Securities [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Fixed income securities | 34,369 | 26,687
Fixed income securities, pledged as collateral | 65,068 | 64,555
Successor [Member] | US Government Debt Securities [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Fixed income securities | 34,369 | 26,687
Fixed income securities, pledged as collateral | 65,068 | 64,555
Successor [Member] | US Government Debt Securities [Member] | Level 1 [Member] |  |
Financial assets: |  |
Fixed income securities | 34,369 | 26,687
Fixed income securities, pledged as collateral | 65,068 | 64,555
Successor [Member] | US Government Debt Securities [Member] | Level 2 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 | 0
Fixed income securities, pledged as collateral | 0 | 0
Successor [Member] | US Government Debt Securities [Member] | Level 3 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 | 0
Fixed income securities, pledged as collateral | 0 | 0
Successor [Member] | U.S. Agency Obligations [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Fixed income securities | 4,148 | 4,212
Successor [Member] | U.S. Agency Obligations [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Fixed income securities | 4,148 | 4,212
Successor [Member] | U.S. Agency Obligations [Member] | Level 1 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 | 0
Successor [Member] | U.S. Agency Obligations [Member] | Level 2 [Member] |  |
Financial assets: |  |
Fixed income securities | 4,148 | 4,212
Successor [Member] | U.S. Agency Obligations [Member] | Level 3 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 | 0
Successor [Member] | Residential Mortgage-Backed Securities [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Fixed income securities | 2,270,543 | 1,977,338
Successor [Member] | Residential Mortgage-Backed Securities [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Fixed income securities | 2,270,543 | 1,977,338
Successor [Member] | Residential Mortgage-Backed Securities [Member] | Level 1 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 | 0
Successor [Member] | Residential Mortgage-Backed Securities [Member] | Level 2 [Member] |  |
Financial assets: |  |
Fixed income securities | 1,619,693 | 1,488,454
Successor [Member] | Residential Mortgage-Backed Securities [Member] | Level 3 [Member] |  |
Financial assets: |  |
Fixed income securities | 650,850 | 488,884
Successor [Member] | Collateralized Debt Obligations [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Fixed income securities | 104,562 | 84,267
Successor [Member] | Collateralized Debt Obligations [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Fixed income securities | 104,562 | 84,267
Successor [Member] | Collateralized Debt Obligations [Member] | Level 1 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 | 0
Successor [Member] | Collateralized Debt Obligations [Member] | Level 2 [Member] |  |
Financial assets: |  |
Fixed income securities | 104,562 | 84,267
Successor [Member] | Collateralized Debt Obligations [Member] | Level 3 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 | 0
Successor [Member] | Asset-backed Securities [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Fixed income securities | 1,114,097 | 840,527
Successor [Member] | Asset-backed Securities [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Fixed income securities | 1,114,097 | 840,527
Successor [Member] | Asset-backed Securities [Member] | Level 1 [Member] |  |
Financial assets: |  |
Fixed income securities | 0 | 0
Successor [Member] | Asset-backed Securities [Member] | Level 2 [Member] |  |
Financial assets: |  |
Fixed income securities | 1,042,277 | 840,527
Successor [Member] | Asset-backed Securities [Member] | Level 3 [Member] |  |
Financial assets: |  |
Fixed income securities | 71,820 | 0
Successor [Member] | Short-Term [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Short term investments | 336,222 | 225,789
Successor [Member] | Short-Term [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Short term investments | 336,222 | 225,789
Successor [Member] | Short-Term [Member] | Level 1 [Member] |  |
Financial assets: |  |
Short term investments | 331,347 | 197,398
Successor [Member] | Short-Term [Member] | Level 2 [Member] |  |
Financial assets: |  |
Short term investments | 4,875 | 28,391
Successor [Member] | Short-Term [Member] | Level 3 [Member] |  |
Financial assets: |  |
Short term investments | 0 | 0
Successor [Member] | Other Assets [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Other assets | 8,687 | 8,696
Successor [Member] | Other Assets [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Other assets | 8,687 | 8,696
Successor [Member] | Other Assets [Member] | Level 1 [Member] |  |
Financial assets: |  |
Other assets | 0 | 0
Successor [Member] | Other Assets [Member] | Level 2 [Member] |  |
Financial assets: |  |
Other assets | 0 | 0
Successor [Member] | Other Assets [Member] | Level 3 [Member] |  |
Financial assets: |  |
Other assets | 8,687 | 8,696
Successor [Member] | Futures Contracts [Member] | Total Fair Value [Member] |  |
Financial assets: |  |
Derivative assets |  | 109
Successor [Member] | Futures Contracts [Member] | Carrying Amount [Member] |  |
Financial assets: |  |
Derivative assets |  | 109
Successor [Member] | Futures Contracts [Member] | Level 1 [Member] |  |
Financial assets: |  |
Derivative assets |  | 109
Successor [Member] | Futures Contracts [Member] | Level 2 [Member] |  |
Financial assets: |  |
Derivative assets |  | 0
Successor [Member] | Futures Contracts [Member] | Level 3 [Member] |  |
Financial assets: |  |
Derivative assets |  | 0
Other Contracts [Member] | Successor [Member] | Total Fair Value [Member] |  |
Financial liabilities: |  |
Derivative liabilities |  | 0
Other Contracts [Member] | Successor [Member] | Carrying Amount [Member] |  |
Financial liabilities: |  |
Derivative liabilities |  | 0
Other Contracts [Member] | Successor [Member] | Level 1 [Member] |  |
Financial liabilities: |  |
Derivative liabilities |  | 0
Other Contracts [Member] | Successor [Member] | Level 2 [Member] |  |
Financial liabilities: |  |
Derivative liabilities |  | 0
Other Contracts [Member] | Successor [Member] | Level 3 [Member] |  |
Financial liabilities: |  |
Derivative liabilities |  | 0
Futures Contracts [Member] | Successor [Member] | Total Fair Value [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 1,356 | 0
Futures Contracts [Member] | Successor [Member] | Carrying Amount [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 1,356 | 0
Futures Contracts [Member] | Successor [Member] | Level 1 [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 1,356 | 0
Futures Contracts [Member] | Successor [Member] | Level 2 [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 0 | 0
Futures Contracts [Member] | Successor [Member] | Level 3 [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 0 | 0
Interest Rate Swaps [Member] | Successor [Member] | Total Fair Value [Member] |  |
Financial liabilities: |  |
Derivative liabilities - interest rate swaps - asset position | (99,841) | (52,128)
Derivative liabilities | 517,441 | 370,943
Interest Rate Swaps [Member] | Successor [Member] | Total Fair Value [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 2,124,045 | 1,965,265
Interest Rate Swaps [Member] | Successor [Member] | Carrying Amount [Member] |  |
Financial liabilities: |  |
Derivative liabilities - interest rate swaps - asset position | (99,841) | (52,128)
Derivative liabilities | 517,441 | 370,943
Interest Rate Swaps [Member] | Successor [Member] | Carrying Amount [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 2,124,045 | 1,965,265
Interest Rate Swaps [Member] | Successor [Member] | Level 1 [Member] |  |
Financial liabilities: |  |
Derivative liabilities - interest rate swaps - asset position | 0 | 0
Derivative liabilities | 0 | 0
Interest Rate Swaps [Member] | Successor [Member] | Level 1 [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 0 | 0
Interest Rate Swaps [Member] | Successor [Member] | Level 2 [Member] |  |
Financial liabilities: |  |
Derivative liabilities - interest rate swaps - asset position | (99,841) | (52,128)
Derivative liabilities | 350,694 | 243,256
Interest Rate Swaps [Member] | Successor [Member] | Level 2 [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 2,124,045 | 1,965,265
Interest Rate Swaps [Member] | Successor [Member] | Level 3 [Member] |  |
Financial liabilities: |  |
Derivative liabilities - interest rate swaps - asset position | 0 | 0
Derivative liabilities | 166,747 | 127,687
Interest Rate Swaps [Member] | Successor [Member] | Level 3 [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 0 | 0
Credit Derivatives [Member] | Successor [Member] | Total Fair Value [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 18,207 | 34,543
Credit Derivatives [Member] | Successor [Member] | Carrying Amount [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 18,207 | 34,543
Credit Derivatives [Member] | Successor [Member] | Level 1 [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 0 | 0
Credit Derivatives [Member] | Successor [Member] | Level 2 [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 0 | 0
Credit Derivatives [Member] | Successor [Member] | Level 3 [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 18,207 | 34,543
Currency Swaps [Member] | Successor [Member] | Total Fair Value [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | (63,167) | (36,862)
Currency Swaps [Member] | Successor [Member] | Carrying Amount [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | (63,167) | (36,862)
Currency Swaps [Member] | Successor [Member] | Level 1 [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | 0 | 0
Currency Swaps [Member] | Successor [Member] | Level 2 [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities | $ (63,167) | (36,862)
Currency Swaps [Member] | Successor [Member] | Level 3 [Member] | Variable Interest Entity [Member] |  |
Financial liabilities: |  |
Derivative liabilities |  | $ 0

X
- Definition Guaranteed investment agreements at fair value. + References No definition available. + Details
Name: | ambc_GuaranteedInvestmentAgreementsFairValueDisclosure
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Fair value of restricted cash and cash equivalents. + References No definition available. + Details
Name: | ambc_RestrictedCashAndCashEquivalentsFairValueDisclosure
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

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://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=36462937&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 Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 25 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=51813488&loc=d3e22054-111558 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (aa) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27232-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=49167202&loc=d3e26610-111562 + Details
Name: | us-gaap_AvailableForSaleSecurities
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 Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash -URI http://asc.fasb.org/extlink&oid=6506951 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Cash Equivalents -URI http://asc.fasb.org/extlink&oid=6507016 + 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://www.xbrl.org/2003/role/presentationRef -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 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624163-113959 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=51825145&loc=SL20226000-175313 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4D -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=51814546&loc=SL51823488-111719 + 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://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 20 -Section 50 -Paragraph 4D -Subparagraph (c)(2) -URI http://asc.fasb.org/extlink&oid=51814546&loc=SL51823488-111719 Reference 2: http://www.xbrl.org/2003/role/presentationRef -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 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -URI http://asc.fasb.org/extlink&oid=56946850&loc=SL5624163-113959 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=51825145&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://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 20 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=51825145&loc=SL20226003-175313 Reference 2: http://www.xbrl.org/2003/role/presentationRef -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 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (a),(c) -URI http://asc.fasb.org/extlink&oid=56946850&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://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 25 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=35740979&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://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 5 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6851643&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://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=36462937&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://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Glossary Loan -URI http://asc.fasb.org/extlink&oid=6517073 + Details
Name: | us-gaap_LoansReceivableFairValueDisclosure
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 Other investments not otherwise specified in the taxonomy. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -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 Reference 2: http://www.xbrl.org/2003/role/presentationRef -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 + Details
Name: | us-gaap_OtherInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Other investments not otherwise specified in the taxonomy that will be realized in a short period of time, usually less than one year or the normal operating cycle, whichever is longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -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 Reference 2: http://www.xbrl.org/2003/role/presentationRef -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://www.xbrl.org/2003/role/presentationRef -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 + Details
Name: | us-gaap_OtherShortTermInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of financial instrument held by the entity for its own account (proprietary securities) for trading or investment purposes that are carried at fair value and pledged to counterparties as collateral for financing transactions. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 30 -Section 50 -Paragraph 1A -Subparagraph (b)(1)(i) -URI http://asc.fasb.org/extlink&oid=55761124&loc=SL6224234-111729 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 860 -SubTopic 30 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6467456&loc=d3e113888-111728 + Details
Name: | us-gaap_SecurityOwnedAndPledgedAsCollateralFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_StatementScenarioAxis=us-gaap_SuccessorMember
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_VariableInterestEntitiesByClassificationOfEntityAxis=us-gaap_VariableInterestEntityPrimaryBeneficiaryMember
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_FairValueByMeasurementBasisAxis=ambc_InvestmentsMeasuredatNAVasaPracticalExpedientMember
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_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_MajorTypesOfDebtAndEquitySecuritiesAxis=us-gaap_CurrencySwapMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FairValueByAssetClassAxis=us-gaap_InterestRateSwapMember
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_USGovernmentAgenciesDebtSecuritiesMember
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_FairValueByAssetClassAxis=us-gaap_ShortTermInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

X
- Details
Name: | us-gaap_FairValueByLiabilityClassAxis=ambc_OtherContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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

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

X
- Details
Name: | us-gaap_FairValueByLiabilityClassAxis=ambc_CreditDerivativesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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