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Reserves for Unpaid Losses and Loss Adjustment Expenses Reserves for Unpaid Losses and Loss Adjustment Expenses (Average Annual Percentage Payout of Incurred Losses and Allocated LAE by Age, Net of Reinsurance) (Details) | Dec. 31, 2016
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Specialty Products | Property |
Short-duration Insurance Contracts, Historical Claims Duration [Line Items] |
1 | 70.10%
2 | 14.60%
3 | 5.90%
4 | 1.10%
5 | 0.30%
6 | 0.20%
7 | 0.40%
8 | 0.00%
9 | 0.00%
10 | 0.00%
Specialty Products | Casualty |
Short-duration Insurance Contracts, Historical Claims Duration [Line Items] |
1 | 11.30%
2 | 24.00%
3 | 17.80%
4 | 9.60%
5 | 4.70%
6 | 2.20%
7 | 0.90%
8 | 0.70%
9 | 0.20%
10 | 0.00%
Specialty Products | Other |
Short-duration Insurance Contracts, Historical Claims Duration [Line Items] |
1 | 61.90%
2 | 29.50%
3 | 0.60%
4 | 0.00%
5 | 0.00%
6 | 0.00%
7 | 0.00%
8 | 0.00%
9 | 0.00%
10 | 0.00%
Specialty Industries | Property |
Short-duration Insurance Contracts, Historical Claims Duration [Line Items] |
1 | 47.40%
2 | 27.30%
3 | 9.90%
4 | 4.10%
5 | 1.80%
6 | 0.70%
7 | 0.20%
8 | 0.10%
9 | 0.00%
10 | 0.00%
Specialty Industries | Casualty |
Short-duration Insurance Contracts, Historical Claims Duration [Line Items] |
1 | 11.40%
2 | 16.20%
3 | 12.90%
4 | 9.70%
5 | 6.80%
6 | 2.50%
7 | 0.80%
8 | 0.10%
9 | 0.20%
10 | 0.20%
Specialty Industries | Other |
Short-duration Insurance Contracts, Historical Claims Duration [Line Items] |
1 | 30.40%
2 | 37.00%
3 | 10.80%
4 | 3.30%
5 | 1.10%
6 | 0.90%
7 | 0.20%
8 | 0.00%
9 | 0.10%
10 | 0.00%

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- Definition Percentage of average annual payout, after reinsurance, in the eighth year after a claim is incurred, beginning with the earliest accident year disclosed for short-duration insurance contracts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 4G -URI http://asc.fasb.org/extlink&oid=65670685&loc=SL65671329-158438 + Details
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- Definition Percentage of average annual payout, after reinsurance, in the fifth year after a claim is incurred, beginning with the earliest accident year disclosed for short-duration insurance contracts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 4G -URI http://asc.fasb.org/extlink&oid=65670685&loc=SL65671329-158438 + Details
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- Definition Percentage of average annual payout, after reinsurance, in the fourth year after a claim is incurred, beginning with the earliest accident year disclosed for short-duration insurance contracts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 4G -URI http://asc.fasb.org/extlink&oid=65670685&loc=SL65671329-158438 + Details
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- Definition Percentage of average annual payout, after reinsurance, in the ninth year after a claim is incurred, beginning with the earliest accident year disclosed for short-duration insurance contracts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 4G -URI http://asc.fasb.org/extlink&oid=65670685&loc=SL65671329-158438 + Details
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- Definition Percentage of average annual payout, after reinsurance, in the first year after a claim is incurred, beginning with the earliest accident year disclosed for short-duration insurance contracts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 4G -URI http://asc.fasb.org/extlink&oid=65670685&loc=SL65671329-158438 + Details
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- Definition Percentage of average annual payout, after reinsurance, in the seventh year after a claim is incurred, beginning with the earliest accident year disclosed for short-duration insurance contracts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 4G -URI http://asc.fasb.org/extlink&oid=65670685&loc=SL65671329-158438 + Details
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- Definition Percentage of average annual payout, after reinsurance, in the tenth year after a claim is incurred, beginning with the earliest accident year disclosed for short-duration insurance contracts. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 4G -URI http://asc.fasb.org/extlink&oid=65670685&loc=SL65671329-158438 + Details
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