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Segment Information - Schedule of Gross Premiums Written, Net Premiums Earned and Net Change in Fair Value of Credit Derivatives (Detail) - USD ($) $ in Thousands | 3 Months Ended | 4 Months Ended | 8 Months Ended | 12 Months Ended
--- | --- | --- | --- | ---
Dec. 31, 2015 | Sep. 30, 2015 | Jun. 30, 2015 | Mar. 31, 2015 | Dec. 31, 2014 | Sep. 30, 2014 | Jun. 30, 2014 | Mar. 31, 2014 | Apr. 30, 2013 | Dec. 31, 2013 | Dec. 31, 2015 | Dec. 31, 2014
Successor [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Gross Premiums Written | $ (18,732) | $ (8,710) | $ (11,192) | $ 1,062 | $ (223,358) | $ (13,700) | $ (45,486) | $ (5,766) |  | $ (80,309) | $ (37,572) | $ (288,310)
Net premiums earned | 114,463 | 71,535 | 60,879 | 65,718 | 33,969 | 64,831 | 65,013 | 82,547 |  | 213,518 | 312,595 | 246,360
Net Change In Fair Value Of Credit Derivatives | $ (3,045) | $ 36,952 | $ 10,293 | $ (2,499) | $ 10,327 | $ 7,416 | $ (1,219) | $ 7,382 |  | 192,869 | 41,701 | 23,906
Successor [Member] | Reportable Geographical Components [Member] | United States [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Gross Premiums Written |  |  |  |  |  |  |  |  |  | (61,255) | (13,028) | (46,279)
Net premiums earned |  |  |  |  |  |  |  |  |  | 165,099 | 229,658 | 197,154
Net Change In Fair Value Of Credit Derivatives |  |  |  |  |  |  |  |  |  | 122,696 | 39,633 | 8,669
Successor [Member] | Reportable Geographical Components [Member] | United Kingdom [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Gross Premiums Written |  |  |  |  |  |  |  |  |  | (7,368) | 3,652 | (221,516)
Net premiums earned |  |  |  |  |  |  |  |  |  | 35,387 | 68,799 | 31,672
Net Change In Fair Value Of Credit Derivatives |  |  |  |  |  |  |  |  |  | 22,548 | 0 | 0
Successor [Member] | Reportable Geographical Components [Member] | Other International [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Gross Premiums Written |  |  |  |  |  |  |  |  |  | (11,686) | (28,196) | (20,515)
Net premiums earned |  |  |  |  |  |  |  |  |  | 13,032 | 14,138 | 17,534
Net Change In Fair Value Of Credit Derivatives |  |  |  |  |  |  |  |  |  | $ 47,625 | $ 2,068 | $ 15,237
Predecessor [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Gross Premiums Written |  |  |  |  |  |  |  |  | $ (14,125) |  |  |
Net premiums earned |  |  |  |  |  |  |  |  | 130,000 |  |  |
Net Change In Fair Value Of Credit Derivatives |  |  |  |  |  |  |  |  | (60,384) |  |  |
Predecessor [Member] | Reportable Geographical Components [Member] | United States [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Gross Premiums Written |  |  |  |  |  |  |  |  | (16,102) |  |  |
Net premiums earned |  |  |  |  |  |  |  |  | 104,594 |  |  |
Net Change In Fair Value Of Credit Derivatives |  |  |  |  |  |  |  |  | (31,134) |  |  |
Predecessor [Member] | Reportable Geographical Components [Member] | United Kingdom [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Gross Premiums Written |  |  |  |  |  |  |  |  | 10,673 |  |  |
Net premiums earned |  |  |  |  |  |  |  |  | 18,071 |  |  |
Net Change In Fair Value Of Credit Derivatives |  |  |  |  |  |  |  |  | (5,861) |  |  |
Predecessor [Member] | Reportable Geographical Components [Member] | Other International [Member] |  |  |  |  |  |  |  |  |  |  |  |
Segment Reporting Information [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Gross Premiums Written |  |  |  |  |  |  |  |  | (8,696) |  |  |
Net premiums earned |  |  |  |  |  |  |  |  | 7,335 |  |  |
Net Change In Fair Value Of Credit Derivatives |  |  |  |  |  |  |  |  | $ (23,389) |  |  |

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- Definition Amount, after premiums ceded to other entities and premiums assumed by the entity, of financial guarantee premiums earned. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 20 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6480758&loc=d3e6811-158387 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 605 -Section 45 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6486662&loc=d3e27175-158546 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.1) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 20 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6480758&loc=d3e6816-158387 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 20 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=6933001&loc=SL5747862-161289 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 605 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6486672&loc=d3e27261-158547 + Details
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