XML 142 R77.htm IDEA: XBRL DOCUMENT
v2.4.0.8

Investments - Summary of Gross Unrealized Losses and Fair Values of Ambac's Available-for-Sale Investments (Detail) (USD $) In Thousands, unless otherwise specified | Jun. 30, 2013 Residential Mortgage-Backed Securities [Member] | Jun. 30, 2013 Other asset-backed securities [Member] | Dec. 31, 2012 Predecessor Ambac [Member] | Dec. 31, 2012 Predecessor Ambac [Member] Short-Term [Member] | Dec. 31, 2012 Predecessor Ambac [Member] Fixed income securities [Member] | Dec. 31, 2012 Predecessor Ambac [Member] Fixed income securities [Member] Municipal Obligations [Member] | Dec. 31, 2012 Predecessor Ambac [Member] Fixed income securities [Member] Corporate Obligations [Member] | Dec. 31, 2012 Predecessor Ambac [Member] Fixed income securities [Member] U.S. government obligations [Member] | Dec. 31, 2012 Predecessor Ambac [Member] Fixed income securities [Member] Residential Mortgage-Backed Securities [Member] | Dec. 31, 2012 Predecessor Ambac [Member] Fixed income securities [Member] Collateralized Debt Obligations [Member] | Dec. 31, 2012 Predecessor Ambac [Member] Fixed income securities [Member] Other asset-backed securities [Member] | Jun. 30, 2013 Successor Ambac [Member] | Jun. 30, 2013 Successor Ambac [Member] Short-Term [Member] | Jun. 30, 2013 Successor Ambac [Member] Fixed income securities [Member] | Jun. 30, 2013 Successor Ambac [Member] Fixed income securities [Member] Municipal Obligations [Member] | Jun. 30, 2013 Successor Ambac [Member] Fixed income securities [Member] Corporate Obligations [Member] | Jun. 30, 2013 Successor Ambac [Member] Fixed income securities [Member] U.S. government obligations [Member] | Jun. 30, 2013 Successor Ambac [Member] Fixed income securities [Member] Residential Mortgage-Backed Securities [Member] | Jun. 30, 2013 Successor Ambac [Member] Fixed income securities [Member] Collateralized Debt Obligations [Member] | Jun. 30, 2013 Successor Ambac [Member] Fixed income securities [Member] Other asset-backed securities [Member] | Jun. 30, 2013 Successor Ambac [Member] Fixed income securities [Member] Foreign obligations [Member] | Jun. 30, 2013 Successor Ambac [Member] Fixed income securities [Member] U.S. agency obligations [Member]
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Schedule of Available-for-sale Securities [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Less than 12 Months, Fair Value |  |  | $ 228,442 | $ 1,194 | $ 227,248 | $ 42,503 | $ 69,727 | $ 26,081 | $ 88,504 | $ 253 | $ 180 | $ 4,152,522 | $ 658 | $ 4,151,864 | $ 1,596,765 | $ 926,601 | $ 282,309 | $ 640,736 | $ 18,823 | $ 549,562 | $ 88,111 | $ 48,957
Less than 12 Months, Gross Unrealized Loss | 23,426 | 23,570 | 7,551 |  | 7,551 | 354 | 1,081 | 626 | 5,319 | 168 | 3 | 137,749 | 4 | 137,745 | 59,103 | 26,437 | 791 | 23,426 | 178 | 23,570 | 4,092 | 148
12 Months or More, Fair Value |  |  |  |  | 455,626 | 4,303 | 132,916 |  | 116,146 | 13,429 | 188,832 |  |  |  |  |  |  |  |  |  |  |
12 Months or More, Fair Value |  |  | 455,626 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
12 Months or More, Gross Unrealized Loss |  |  |  |  | 70,164 | 29 | 8,036 |  | 15,236 | 360 | 46,503 |  |  |  |  |  |  |  |  |  |  |
12 Months or More, Gross Unrealized Losses |  |  | 70,164 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total, Fair Value |  |  |  |  | 682,874 | 46,806 | 202,643 | 26,081 | 204,650 | 13,682 | 189,012 |  |  |  |  |  |  |  |  |  |  |
Total, Fair Value |  |  | 684,068 | 1,194 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Total, Gross Unrealized Loss |  |  |  |  | 77,715 | 383 | 9,117 | 626 | 20,555 | 528 | 46,506 |  |  |  |  |  |  |  |  |  |  |
Total, Gross Unrealized Loss |  |  | $ 77,715 |  |  |  |  |  |  |  |  | $ 137,749 |  |  |  |  |  |  |  |  |  |

X
- Definition Sum of the gross unrealized losses as of the balance sheet date on all investments. + References No definition available. + Details
Name: | ambc_GrossUnrealizedLossOnInvestment
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Total fair value of securities in a continuous unrealized loss position. + References No definition available. + Details
Name: | ambc_SecuritiesContinuousUnrealizedLossPositionFairValue
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Aggregate losses of securities in a continuous unrealized loss position for greater than twelve months. + References No definition available. + Details
Name: | ambc_SecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerAggregateLosses
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value of securities in a continuous unrealized loss position for greater than twelve months. + References No definition available. + Details
Name: | ambc_SecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
Namespace Prefix: | ambc_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of the excess of amortized cost basis over fair value of securities that have been in a loss position for twelve months or longer for securities which are categorized neither as held-to-maturity nor trading securities. + References No definition available. + Details
Name: | us-gaap_AvailableforsaleSecuritiesContinuousUnrealizedLossPosition12MonthsOrLongerAggregateLosses2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of the excess of amortized cost basis over fair value of securities in a loss position and categorized neither as held-to-maturity nor trading securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27290-111563 + Details
Name: | us-gaap_AvailableforsaleSecuritiesContinuousUnrealizedLossPositionAggregateLosses2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27290-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS115-1/124-1 -Paragraph 17 -Subparagraph a(1) -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 03-1 -Paragraph 21 -Subparagraph a(2) -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of the excess of amortized cost basis over fair value of securities that have been in a loss position for less than twelve months for securities categorized neither as held-to-maturity nor trading securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27290-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27337-111563 + Details
Name: | us-gaap_AvailableforsaleSecuritiesContinuousUnrealizedLossPositionLessThan12MonthsAggregateLosses2
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for less than twelve months. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27337-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27290-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS115-1/124-1 -Paragraph 17 -Subparagraph a(1) -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 03-1 -Paragraph 21 -Subparagraph a(2) -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionLessThanTwelveMonthsFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition This item represents the aggregate fair value of investments in debt and equity securities categorized neither as held-to-maturity nor trading securities that have been in a continuous unrealized loss position for twelve months or longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27337-111563 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27290-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name FASB Staff Position (FSP) -Number FAS115-1/124-1 -Paragraph 17 -Subparagraph a(1) -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Emerging Issues Task Force (EITF) -Number 03-1 -Paragraph 21 -Subparagraph a(2) -LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy. + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionTwelveMonthsOrLongerFairValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration