Financial Guarantee Insurance Contracts - Summary of Gross Premium Receivable Roll-Forward (Direct and Assumed Contracts) (Detail) (USD $) In Thousands, unless otherwise specified	8 Months Ended	12 Months Ended	4 Months Ended	12 Months Ended
Dec. 31, 2013	Dec. 31, 2014	Apr. 30, 2013	Dec. 31, 2012
Successor [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Beginning premium receivable	$ 1,531,631	$ 1,453,021
Premium receipts	(82,071)	(126,497)
Adjustments for changes in expected and contractual cash flows	(91,241)	(322,443)
Accretion of premium receivable discount	26,184	36,651
Financial Guarantee Insurance Contracts Premium Receivable Deconsolidation Of Certain Variable Interest Entity	45,883
Uncollectable premiums	(15,262)	(2,518)
Other adjustments (including foreign exchange)	37,897	(37,607)
Ending premium receivable	1,453,021	1,000,607
Predecessor [Member]
Financial Guarantee Insurance Contracts, Premium Receivable [Roll Forward]
Beginning premium receivable			1,620,621	2,028,479
Premium receipts			(48,296)	(155,626)
Adjustments for changes in expected and contractual cash flows			(28,237)	(299,906)
Accretion of premium receivable discount			14,740	50,407
Uncollectable premiums			(634)	(28,031)
Other adjustments (including foreign exchange)			(26,563)	25,298
Ending premium receivable			$ 1,531,631	$ 1,620,621

Financial guarantee insurance contracts premium receivable deconsolidation of certain variable interest entity.

No definition available.

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of increase (decrease) in the allowance for doubtful accounts.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Period Type:	duration

- Definition

Amount of the premium receivable for financial guarantee insurance contracts reported in the statement of financial position. This element primarily would consist of those financial guarantee insurance contracts which premiums are to be collected over the contract period, but may, on occasion, include premiums which are to be collected in full at inception, but which straddle a financial reporting period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 310

-Section 50

-Paragraph 3

-Subparagraph (c)(1),(5)

-URI http://asc.fasb.org/extlink&oid=6933075&loc=SL5748726-161290

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

Amount of premium payments received during the period for premiums receivable on financial guarantee insurance contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 310

-Section 50

-Paragraph 3

-Subparagraph (c)(2)

-URI http://asc.fasb.org/extlink&oid=6933075&loc=SL5748726-161290

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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- Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the accretion of the discount for premiums receivable on financial guarantee insurance contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 310

-Section 50

-Paragraph 3

-Subparagraph (c)(4)(iii)

-URI http://asc.fasb.org/extlink&oid=6933075&loc=SL5748726-161290

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This element represents adjustments to the premium receivable related to financial guarantee insurance contracts due to changes in the period of the contract.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 310

-Section 50

-Paragraph 3

-Subparagraph (c)(4)(i)

-URI http://asc.fasb.org/extlink&oid=6933075&loc=SL5748726-161290

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

This element represents other adjustments to premiums receivable on financial guarantee insurance contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 310

-Section 50

-Paragraph 3

-Subparagraph (c)(4)(iv)

-URI http://asc.fasb.org/extlink&oid=6933075&loc=SL5748726-161290

+ Details

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