XML 94 R75.htm IDEA: XBRL DOCUMENT
v3.19.1

Investments Equity Investments (Details) - USD ($) $ in Thousands | Mar. 31, 2019 | Dec. 31, 2018
--- | --- | ---
Schedule of Equity Method Investments [Line Items] |  |
Other investments | $ 428,556 | $ 391,217
Real Estate [Member] |  |
Schedule of Equity Method Investments [Line Items] |  |
Other investments | 16,150 | 16,123
Interest Rate Contract [Member] |  |
Schedule of Equity Method Investments [Line Items] |  |
Other investments | 207,704 | 177,357
Illiquid Investments [Member] |  |
Schedule of Equity Method Investments [Line Items] |  |
Other investments | 85,323 | 84,297
Insurance Linked [Member] |  |
Schedule of Equity Method Investments [Line Items] |  |
Other investments | 28,746 | 29,318
Equity [Member] |  |
Schedule of Equity Method Investments [Line Items] |  |
Other investments | 49,122 | 43,954
Equity investments in pooled funds [Member] |  |
Schedule of Equity Method Investments [Line Items] |  |
Other investments | 387,045 | 351,049
Readily determinable fair value [Member] | Interest Rate Contract [Member] |  |
Schedule of Equity Method Investments [Line Items] |  |
Other investments | $ 53,135 | $ 27,154

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 Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ScheduleOfEquityMethodInvestmentsLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_RealEstateMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_InterestRateContractMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=ambc_IlliquidInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=ambc_InsuranceLinkedMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_EquityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=ambc_EquityinvestmentsinpooledfundsMember
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: |