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Third-Party Reinsurance (Details 2) | 12 Months Ended |  | 12 Months Ended |  | 12 Months Ended | 127 Months Ended |  |  | 12 Months Ended | 1 Months Ended | 12 Months Ended | 1 Months Ended | 12 Months Ended | 127 Months Ended | 12 Months Ended |  | 12 Months Ended |  | 12 Months Ended |  | 12 Months Ended | 1 Months Ended | 12 Months Ended | 1 Months Ended | 12 Months Ended |
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Dec. 31, 2011 USD ($) | Dec. 31, 2010 USD ($) | Dec. 31, 2009 USD ($) | Dec. 31, 2007 Y | Dec. 31, 2008 USD ($) | Dec. 31, 2011 Healthcare professional liability USD ($) | Dec. 31, 2011 NICO Cover contract | Dec. 31, 2010 Imagine Re Sirius America USD ($) | Dec. 31, 2009 Imagine Re Sirius America USD ($) | Dec. 31, 2011 OneBeacon USD ($) | Dec. 31, 2010 OneBeacon USD ($) | Dec. 31, 2009 OneBeacon USD ($) | Dec. 31, 2011 OneBeacon USD ($) | Dec. 31, 2001 OneBeacon rating contract | Dec. 31, 2011 OneBeacon Maximum USD ($) | Dec. 31, 2011 OneBeacon Property catastrophe reinsurance program USD ($) | Dec. 31, 2011 OneBeacon Property catastrophe reinsurance program Minimum USD ($) | Dec. 31, 2011 OneBeacon Property catastrophe reinsurance program Maximum USD ($) | Jun. 30, 2010 OneBeacon Northeast homeowners business USD ($) | Dec. 31, 2009 OneBeacon Northeast homeowners business USD ($) | Dec. 31, 2011 OneBeacon Property-per-risk reinsurance program USD ($) | Dec. 31, 2011 OneBeacon Property-per-risk reinsurance program Minimum USD ($) | Dec. 31, 2011 OneBeacon Property-per-risk reinsurance program Maximum USD ($) | Dec. 31, 2011 OneBeacon Casualty reinsurance program Minimum USD ($) | Dec. 31, 2011 OneBeacon Casualty reinsurance program Maximum USD ($) | Jun. 30, 2001 OneBeacon NICO Cover USD ($) | Dec. 31, 2011 OneBeacon NICO Cover USD ($) | Dec. 31, 2011 OneBeacon NICO Cover USD ($) | Dec. 31, 2011 OneBeacon NICO Cover Maximum USD ($) | Dec. 31, 2011 OneBeacon GRC Cover USD ($) | Dec. 31, 2011 OneBeacon GRC Cover Maximum USD ($) | Dec. 31, 2011 OneBeacon National Indemnity Company and General Reinsurance Corporation USD ($) | Dec. 31, 2011 OneBeacon Hanover Insurance Group Ltd. USD ($) | Dec. 31, 2011 OneBeacon Tokio Marine and Nichido Fire USD ($) | Dec. 31, 2011 OneBeacon Tower Group Inc. USD ($) | Dec. 31, 2011 OneBeacon Munich Reinsurance America USD ($) | Dec. 31, 2011 OneBeacon General Reinsurance Corporation GRC Cover USD ($) | Dec. 31, 2010 OneBeacon General Reinsurance Corporation GRC Cover USD ($) | Dec. 31, 2011 Sirius group USD ($) | Dec. 31, 2010 Sirius group USD ($) | Dec. 31, 2009 Sirius group USD ($) | Apr. 30, 2011 Sirius group Catastrophe excess of loss cover USD ($) Y | Apr. 30, 2010 Sirius group New Zealand earthquake losses cover USD ($) | Dec. 31, 2011 Sirius group New Zealand earthquake losses cover USD ($) | Apr. 30, 2009 Sirius group Chile earthquake losses cover USD ($) | Dec. 31, 2010 Sirius group Chile earthquake losses cover USD ($) | Dec. 31, 2012 Sirius group Facultative and proportional aviation portfolio reinsurance Minimum USD ($) | Dec. 31, 2012 Sirius group Facultative and proportional aviation portfolio reinsurance Maximum USD ($) | Dec. 31, 2011 Sirius group Non-proportional aviation portfolio reinsurance USD ($) | Dec. 31, 2011 Sirius group Non-proportional aviation portfolio reinsurance Minimum USD ($) | Dec. 31, 2011 Sirius group Non-proportional aviation portfolio reinsurance Maximum USD ($) | Dec. 31, 2011 Sirius group Personal accident and life USD ($) | Dec. 31, 2011 Sirius group Personal accident and life EUR (€) | Dec. 31, 2011 Sirius group Olympus USD ($) | Dec. 31, 2011 Sirius group Lloyds of London USD ($) | Dec. 31, 2011 Sirius group General Reinsurance Corporation USD ($) | Dec. 31, 2011 Sirius group Swiss Re Group USD ($) | Dec. 31, 2011 Sirius group Michigan Catastrophic Claims Association USD ($)
Third-Party Reinsurance |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Period for which the U.S. government extended the Terrorism Act (in years) |  |  |  | 7 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of certified losses required to be shared by federal government under Terrorism Risk Insurance Act |  |  |  |  |  |  |  |  |  | 85.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Aggregate liability to be paid by the government and industry without further action by Congress |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 100,000,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated individual retention level for commercial policies subject to the Terrorism Act |  |  |  |  |  |  |  |  |  | 100,000,000 |  |  | 100,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount of loss on a single catastrophe retained, first layer |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 50,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount of loss on a single catastrophe reinsured, second layer |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 175,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
First retention percentage of loss on a single catastrophe reinsured, second layer |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 26.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount of loss on a single catastrophe reinsured, first retention slab for second layer |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 50,000,000 | 100,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Second retention percentage of loss on a single catastrophe reinsured, second layer |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 10.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount of loss on a single catastrophe reinsured, second retention slab for second layer |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 100,000,000 | 175,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount of loss on a single catastrophe retained, third layer |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 225,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
The percentage ceded under quota share reinsurance agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 30.00% |  |  |  |  |  |  |  |  |  |  |  |  |  | 100.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 15.00% |  |  |  |  |  |  |  |  |
Premiums ceded under quota share agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 25,600,000 | 59,900,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Reinsurance program, reinsured losses |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 5,000,000 | 21,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 150,000,000 | 2,250,000,000 |  |  |  |  |  |  |  |  |  |
Amount above which individual risk facultative reinsurance may be purchased |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 100,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Reinsurance protection on an individual risk basis for terrorism losses |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 10,000,000 | 100,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of reinsurance contracts the seller caused OneBeacon to purchase immediately prior to the entity's acquisition of OneBeacon |  |  |  |  |  |  | 1 |  |  |  |  |  |  | 2 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of ratings in Standard & Poors best ratings |  |  |  |  |  |  |  |  |  |  |  |  |  | 21 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Number of ratings in A.M. Best ratings |  |  |  |  |  |  |  |  |  |  |  |  |  | 15 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Period for which reinsurance cover was renewed (in years) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Cover under reinsurance contract |  |  |  |  |  | 20,000,000 |  |  |  |  |  |  |  |  |  |  |  | 40,000,000 |  |  |  |  |  |  |  | 2,500,000,000 |  |  | 2,500,000,000 |  | 570,000,000 |  |  |  |  |  |  |  |  |  |  | 61,000,000 | 65,000,000 |  | 65,000,000 |  |  |  |  |  |  | 13,000,000 | 10,000,000 |  |  |  |  |
Amount of retention of losses by the entity |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 10,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 35,000,000 | 45,000,000 | 45,000,000 | 35,000,000 |  |  |  |  |  |  | 7,000,000 | 5,000,000 |  |  |  |  |
Amount of earthquake losses at which reinsurance will be fully recovered |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 110,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Ceded estimated incurred losses |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,300,000,000 | 2,300,000,000 |  | 562,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Reinsurance receivables paid by the reinsurer |  |  |  |  |  |  |  |  |  |  |  |  | 1,400,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 73,500,000 | 61,300,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of utilized coverage that relates to uncollectible Third Party Recoverables |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 8.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Utilized coverage from that relates to uncollectible Third-Party Recoverables |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 184,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Utilized coverage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 65,000,000 |  |  |  |  |  |  |  |  |  |  |  |
Utilized asbestos and environmental coverage |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 2,300,000,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Reinsurance recoverable on paid losses | 30,500,000 | 63,100,000 |  |  |  |  |  |  |  | 16,500,000 |  |  | 16,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 13,900,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Reinsurance recoverable on unpaid losses | 2,507,300,000 | 2,344,000,000 | 2,771,500,000 |  | 3,049,000,000 |  |  |  |  | 2,330,800,000 |  |  | 2,330,800,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 339,700,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Purchase accounting adjustments |  |  |  |  |  |  |  |  |  | 163,300,000 |  |  | 163,300,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Reinsurance recoverables | 2,537,800,000 | 2,407,100,000 |  |  |  |  |  |  |  | 2,184,100,000 | 1,937,700,000 |  | 2,184,100,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 1,540,600,000 | 90,900,000 | 57,100,000 | 35,100,000 | 26,400,000 |  |  | 353,700,000 | 469,400,000 |  |  |  |  |  |  |  |  |  |  |  |  |  | 35,500,000 | 27,200,000 | 42,700,000 | 40,200,000 | 14,600,000
Percentage of total paid and unpaid reinsurance recoverables |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 66.00% | 4.00% | 2.00% | 1.00% | 1.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 10.00% | 8.00% | 12.00% | 11.00% | 4.00%
Percentage of reinsurance recoverable that is collateralized |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 100.00% | 8.00% | 1.00% | 20.00% |
Third-Party Recoverables in which reinsurer would pay if they are unable to collect from third-party reinsurers |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 198,300,000 | 198,300,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Reinsurance recoverable from various third-party reinsurers, guaranteed by the third-party reinsurer under reinsurance agreement |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 30,500,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Protection in first event industry loss warranties (ILW) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 400,000,000 | 900,000,000 |  |  |  |  |  |  |
Industry event level for first event industry loss warranties (ILW) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 30,000,000 |  |  |  |  |  |  |  |  |
Protection in second event industry loss warranties (ILW) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 6,000,000 |  |  |  |  |  |  |  |  |
Industry event level for second event industry loss warranties (ILW) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 300,000,000 | 600,000,000 |  |  |  |  |  |  |
Percentage of trade credit business under a quota share retrocession |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 19.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of trade credit business under a renewed quota share retrocession |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 20.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Percentage of bond business under a renewed quota share retrocession |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 50.00% |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount of unamortized deferred gains |  |  |  |  |  |  |  |  | 16,300,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Amount of deferred gains recognized |  |  |  |  |  |  |  | 16,300,000 | 4,600,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | (16,300,000) |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |
Case incurred loss and ALAE during the period | $ 1,206,900,000 | $ 1,389,200,000 | $ 1,424,100,000 |  |  |  |  |  |  | $ 580,900,000 | $ 858,200,000 | $ 1,005,300,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | $ 626,000,000 | $ 531,000,000 | $ 418,800,000 |  |  | $ 44,400,000 |  |  |  |  |  |  |  |  |  |  |  |  |  |

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- Definition Provision for benefits, claims and claims settlement expenses incurred during the period net of the effects of contracts assumed and ceded. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Paragraph 5 -Article 7 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 225 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04.5) -URI http://asc.fasb.org/extlink&oid=6879464&loc=d3e573970-122913 + Details
Name: | us-gaap_PolicyholderBenefitsAndClaimsIncurredNet
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The portion of reinsurance receivables representing the aggregate amount of estimated amounts due as of the balance sheet date from another insurer; also called reinsurance recoverables or unpaid losses recoverable, that are expected based upon statistical projections of incurred claims and claims settlement expenses which have not yet been reported to the insurer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 310 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6485522&loc=d3e21409-158489 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 7 -Section 03 -Paragraph 6 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 113 -Paragraph 14, 15 -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 Accounting Standards Codification -Topic 944 -SubTopic 310 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6485522&loc=d3e21412-158489 + Details
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- Definition Receivables currently due from reinsurers for ceded claims paid. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 310 -Section 45 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6485522&loc=d3e21409-158489 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 210.7-03.6) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 7 -Section 03 -Paragraph 6 Reference 4: 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 -Subparagraph (a)(2) Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 113 -Paragraph 14, 15 -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 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 310 -Section 45 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=6485522&loc=d3e21412-158489 + Details
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- Definition The known and estimated amount recoverable as of the balance sheet date from reinsurers for claims paid or incurred by the ceding insurer and associated claims settlement expenses, including estimated amounts for claims incurred but not reported, and policy benefits, net of any related valuation allowance. + References Reference 1: 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.(a),6) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 7 -Section 03 -Paragraph 6 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Statement of Financial Accounting Standard (FAS) -Number 113 -Paragraph 14, 16, 27, 113 -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 Accounting Standards Codification -Topic 944 -SubTopic 20 -Section 50 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=6480758&loc=d3e6824-158387 + Details
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- Definition The number of ratings in the A.M. Best rating system. + References No definition available. + Details
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- Definition Represents the amount of catastrophe losses at which the entire cover under the reinsurance contract will be fully utilized by the entity. + References No definition available. + Details
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Balance Type: | debit
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- Definition Represents the amount of exposure to losses resulting from the insurance claims retained by the entity. + References No definition available. + Details
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Balance Type: | debit
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- Definition Represents the cover which the entity has purchased in case of first event industry loss warranties under the aviation reinsurance program. + References No definition available. + Details
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- Definition Represents the cover which the entity has purchased in case of second event industry loss warranties under the aviation reinsurance program. + References No definition available. + Details
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Balance Type: | credit
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- Definition Represents the amount of aggregate industry losses required for availing the cover which the entity has purchased in case of first event industry loss warranties under the aviation reinsurance program. + References No definition available. + Details
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Balance Type: | credit
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- Definition Represents the amount of aggregate industry losses required for availing the cover which the entity has purchased in case of second event industry loss warranties under the aviation reinsurance program. + References No definition available. + Details
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Balance Type: | debit
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- Definition Total consideration paid and payable to reinsurers during the period pursuant to terms of quota share reinsurance arrangements. + References No definition available. + Details
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- Definition Represents the estimated amount of loss ceded as of the balance sheet date. + References No definition available. + Details
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- Definition Represents the estimated individual retention level for commercial policies subject to the Terrorism Act in the next fiscal year based on net written premiums in the current fiscal year. + References No definition available. + Details
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- Definition Represents the amount above which individual risk facultative reinsurance may be purchased. + References No definition available. + Details
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Balance Type: | debit
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- Definition Represents the aggregate liability to be paid by the government and industry without further action by Congress. + References No definition available. + Details
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- Definition Represents the number of reinsurance contracts the seller caused OneBeacon to purchase from subsidiaries of Berkshire Hathaway Inc. immediately prior to the entity's acquisition of OneBeacon. + References No definition available. + Details
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- Definition Represents the percentage of a top reinsurer's recoverable amounts that are collateralized. + References No definition available. + Details
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Balance Type: | na
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- Definition Represents the percentage of ceded bond business under a renewed quota share retrocession. + References No definition available. + Details
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- Definition Represents the percentage of certified losses required to be shared by federal government once a company meets certain conditions. + References No definition available. + Details
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- Definition Represents the percentage ceded under quota share reinsurance agreement. + References No definition available. + Details
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- Definition The respective third party reinsurers' percentage share of the total paid and unpaid reinsurance recoverables. + References No definition available. + Details
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- Definition Represents the percentage of ceded trade credit business under a quota share retrocession. + References No definition available. + Details
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- Definition Represents the percentage of ceded trade credit business under a Renewed quota share retrocession. + References No definition available. + Details
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- Definition Represents the period for which the applicability of the act was extended during the reporting period. + References No definition available. + Details
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- Definition First layer of reinsurance agreement that is retained by the entity. + References No definition available. + Details
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Balance Type: | debit
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- Definition Represents the retention for the second layer of the reinsurance agreement. + References No definition available. + Details
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- Definition Second layer of reinsurance agreement, in excess of the first layer, that is reinsured. + References No definition available. + Details
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Balance Type: | debit
Period Type: | duration

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- Definition Represents the retention percentage between $50 million and $100 million for the second layer of the reinsurance agreement. + References No definition available. + Details
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- Definition Represents the retention percentage between $100 million and $175 million for the second layer of the reinsurance agreement. + References No definition available. + Details
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- Definition Represents the retention for the second layer of the reinsurance agreement. + References No definition available. + Details
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- Definition Third layer of reinsurance agreement, in excess of the second layer, that is retained by the entity. + References No definition available. + Details
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- Definition Represents the period for which the reinsurance contract has been renewed. + References No definition available. + Details
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- Details
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- Definition Represents the reinsured losses under reinsurance program. + References No definition available. + Details
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Balance Type: | debit
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- Definition Represents the reinsurance protection on an individual risk basis for terrorism losses under reinsurance program. + References No definition available. + Details
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- Definition Represents amount of incurred losses paid by the reinsurer through the reporting date. + References No definition available. + Details
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- Definition Represents the cover amount under reinsurance contracts. + References No definition available. + Details
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- Definition Represents the amount of deferred gains recognized during the period, attributable to the collection of the recoverables that were due under the reinsurance contract. + References No definition available. + Details
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- Definition Represents the amount of unamortized deferred gains as of the balance sheet date, attributable to the amount of recoverables due for collection under the reinsurance contract. + References No definition available. + Details
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- Definition Purchase accounting adjustments related to reinsurance recoverables. + References No definition available. + Details
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- Definition Reinsurance recoverables from various third party reinsurers that are guaranteed under the terms of a 100% quota share reinsurance agreement. + References No definition available. + Details
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- Definition The number of ratings in the Standard & Poors Best rating system. + References No definition available. + Details
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Balance Type: | na
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- Definition Amount of third party recoverables which reinsurer would pay if they are unable to collect from third party reinsurers. + References No definition available. + Details
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Balance Type: | debit
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- Definition Represents the utilized asbestos and environmental coverage from reinsurer. + References No definition available. + Details
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Balance Type: | credit
Period Type: | duration

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- Definition Represents the utilized coverage from reinsurer. + References No definition available. + Details
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Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

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- Definition Represents the utilized coverage from reinsurer that relates to uncollectible Third Party Recoverables. + References No definition available. + Details
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Balance Type: | credit
Period Type: | duration

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- Definition Represents the percentage of utilized coverage from reinsurer that relates to uncollectible Third Party Recoverables. + References No definition available. + Details
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