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Reserve for Losses and Loss Expenses (Roll Forward of Gross and Net Asbestos and Net Environmental Incurred Losses and Loss Expenses and Related Reserves) (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2015 | Dec. 31, 2014 | Dec. 31, 2013
Liability for Claims and Claims Adjustment Expense [Line Items] |  |  |
Salvage and Subrogation Recoveries, Value | $ 62,100 | $ 65,100 | $ 61,000
Reserves for losses and loss expenses at beginning of year, gross | 30,653 | 32,764 | 35,575
Incurred losses and loss expenses, gross | (2,968) | (167) | (347)
Less: losses and loss expenses paid, gross | (3,210) | (2,278) | (3,158)
Reserves for losses and loss expenses at the end of year, gross | 30,411 | 30,653 | 32,764
Reserves for losses and loss expenses at beginning of year, net | 22,994 | 25,167 | 27,769
Incurred losses and loss expenses, net | (3,320) | 0 | (68)
Less: losses and loss expenses paid, net | (3,153) | (2,173) | (2,670)
Reserves for losses and loss expenses at the end of year, net | 23,161 | 22,994 | 25,167
Asbestos [Member] |  |  |
Liability for Claims and Claims Adjustment Expense [Line Items] |  |  |
Reserves for losses and loss expenses at beginning of year, gross | 8,751 | 8,897 | 9,170
Incurred losses and loss expenses, gross | (428) | (60) | 0
Less: losses and loss expenses paid, gross | (299) | (206) | (273)
Reserves for losses and loss expenses at the end of year, gross | 8,024 | 8,751 | 8,897
Reserves for losses and loss expenses at beginning of year, net | 7,314 | 7,518 | 7,791
Incurred losses and loss expenses, net | (77) | 0 | 0
Less: losses and loss expenses paid, net | (444) | (204) | (273)
Reserves for losses and loss expenses at the end of year, net | 6,793 | 7,314 | 7,518
Enviromental [Member] |  |  |
Liability for Claims and Claims Adjustment Expense [Line Items] |  |  |
Reserves for losses and loss expenses at beginning of year, gross | 21,902 | 23,867 | 26,405
Incurred losses and loss expenses, gross | (3,396) | (107) | (347)
Less: losses and loss expenses paid, gross | (2,911) | (2,072) | (2,885)
Reserves for losses and loss expenses at the end of year, gross | 22,387 | 21,902 | 23,867
Reserves for losses and loss expenses at beginning of year, net | 15,680 | 17,649 | 19,978
Incurred losses and loss expenses, net | (3,397) | 0 | (68)
Less: losses and loss expenses paid, net | (2,709) | (1,969) | (2,397)
Reserves for losses and loss expenses at the end of year, net | $ 16,368 | $ 15,680 | $ 17,649

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- Definition Carrying amount as of the balance sheet date of reserves for the costs of settling insured claims and costs incurred in the claims settlement process attributable to asbestos and environmental claims, before estimated recoveries from reinsurers. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6482485&loc=d3e14764-158437 + Details
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- Definition Amount of asbestos claims paid in the current period, before estimated recoveries from reinsurers. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6482485&loc=d3e14784-158437 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6482485&loc=d3e14764-158437 + Details
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- Definition Increase in asbestos and environmental reserve based on known and estimated costs of settling insured claims and costs incurred in the claims settlement process, before estimated recoveries from reinsurers. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 3 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6482485&loc=d3e14764-158437 + Details
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- Definition Carrying amount as of the balance sheet date of reserves for the costs of settling insured claims and costs incurred in the claims settlement process attributable to asbestos and environmental claims, net of estimated reinsurance recoveries. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6482485&loc=d3e14764-158437 + Details
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- Definition Amount of asbestos claims paid in the current period, net of reinsurance recoveries. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6482485&loc=d3e14764-158437 + Details
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- 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
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- Definition The estimated amount as of the balance sheet date to be received by an insurer from the sale of property (usually damaged) on which the insurer has paid a total claim to the insured and has obtained title to the property and the right of an insurer to pursue any course of recovery of damages, in its name or in the name of the policyholder, against a third party who is liable for costs relating to an insured event that have been paid by the insurer. Estimated salvage and subrogation is generally deducted from the liability for unpaid claims. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 30 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6482241&loc=d3e13779-158432 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 30 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6482241&loc=d3e13783-158432 + Details
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