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Unpaid losses and loss expenses Unpaid losses and loss expenses (RF Details) - USD ($) $ in Millions | 9 Months Ended |  |
--- | --- | --- | ---
Sep. 30, 2017 | Sep. 30, 2016 | Dec. 31, 2016 | Jan. 14, 2016
Unpaid Losses and Loss Expenses [Roll Forward] |  |  |  |  |
Gross unpaid losses and loss expenses, beginning of year |  | $ 60,540 | $ 37,303 |  |
Reinsurance Recoverable on unpaid losses, beginning of year | [1] | (12,708) | (10,741) |  |
Net unpaid loss, beginning of period |  | 47,832 | 26,562 |  |
Acquisition of subsidiaries |  |  |  | $ 0 | $ 21,402
Total, Beginning of year |  | 47,832 | 47,964 |  |
Current Year Claims and Claims Adjustment Expense |  | 14,963 | 13,169 |  |
PPD (Favorable) / Adverse | [2] | (781) | (972) |  |
Total, Incurred |  | 14,182 | 12,197 |  |
Net loss and loss expenses paid, Current Year |  | 3,937 | 3,865 |  |
Net losses and loss expenses Paid, Prior Years |  | 8,389 | 7,470 |  |
Total, Paid |  | 12,326 | 11,335 |  |
Liability For Unpaid Claims And Claims Adjustment Expense Foreign Currency Revaluation And Other |  | 596 | (155) |  |
Net unpaid Loss, end of period |  | 50,283 | 48,671 |  |
Reinsurance Recoverables on unpaid losses, end of year | [1] | 13,870 | 12,676 |  |
Gross unpaid losses and loss expenses, end of year |  | 64,153 | 61,347 |  |
prior period development, net adjustments |  | $ 110 | $ 75 |  |
[1] | Net of provision for uncollectible reinsurance
[2] | Relates to prior period loss reserve development only and excludes prior period development related to reinstatement premiums, expense adjustments, and earned premiums totaling $110 million and $75 million for the nine months ended September 30, 2017 and 2016, respectively.

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- Definition Liability For Unpaid Claims And Claims Adjustment Expense Reported And Incurred But Not Reported Claims Net Of Reinsurance Recoverable Adjusted For Subsidiary Acquisition + References No definition available. + Details
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- Definition The amount needed to reflect the estimated ultimate cost of settling claims relating to insured events that have occurred on or before the balance sheet date, whether or not reported to the insurer at that date. + 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=65670824&loc=d3e14764-158437 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 3 -Subparagraph (cc) -URI http://asc.fasb.org/extlink&oid=65670824&loc=d3e14764-158437 + Details
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- Definition Amount, after effects of reinsurance, of payments to settle claims incurred in the current period and related claims settlement costs. + 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=65670824&loc=d3e14764-158437 + Details
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- Definition Amount, after effects of reinsurance, of expense (reversal of expense) for claims incurred and costs incurred in the claim settlement process. + 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=65670824&loc=d3e14764-158437 + Details
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- Definition Liability as of the balance sheet date for amounts representing estimated cost of settling unpaid claims under the terms of the underlying insurance policies, less estimated reinsurance recoveries on such claims. This includes an estimate for claims which have been incurred but not reported. Claim adjustment expenses represent the costs estimated to be incurred in the settlement of unpaid claims. + 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(13)(a)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 3 -Subparagraph (cc) -URI http://asc.fasb.org/extlink&oid=65670824&loc=d3e14764-158437 Reference 3: 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=65670824&loc=d3e14764-158437 + Details
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- Definition Amount, after valuation allowance, recoverable under reinsurance contracts for losses reported to the ceding insurer but not yet paid and amounts expected for incurred losses and settlement expenses, which have not yet been reported to the ceding insurer. + 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 (cc) -URI http://asc.fasb.org/extlink&oid=65670824&loc=d3e14764-158437 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 50 -Paragraph 3 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=65670824&loc=d3e14764-158437 Reference 3: 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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