The effect of exchange rate changes on foreign-denominated balances 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. The balance may include other non-material items.

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Amount, after effects of reinsurance, of expense for claims incurred in the current reporting period and related claims settlement costs.

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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

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 235
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-18)
-URI http://asc.fasb.org/extlink&oid=34713774&loc=d3e575016-122915

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RESERVE FOR LOSSES AND LOSS EXPENSES (DETAILS 3) - USD ($) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Apr. 30, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Additional Information Related to Net Incurred Losses [Line Items]
Current year				$ 1,887,715	$ 1,818,672
Foreign exchange and other				112,649	183,360
Net favorable (adverse) prior year reserve development		$ 76,019	$ 45,125	224,131	165,804
Short Tail Lines Insurance And Reinsurance Business [Member]
Additional Information Related to Net Incurred Losses [Line Items]
Net favorable (adverse) prior year reserve development		41,000	38,000	116,000	112,000
Professional Lines Insurance and Reinsurance Business [Member]
Additional Information Related to Net Incurred Losses [Line Items]
Net favorable (adverse) prior year reserve development		12,000		28,000
Professional Lines Reinsurance Business [Member]
Additional Information Related to Net Incurred Losses [Line Items]
Net favorable (adverse) prior year reserve development					25,000
Professional Lines Insurance Business [Member]
Additional Information Related to Net Incurred Losses [Line Items]
Net favorable (adverse) prior year reserve development			(15,000)		(16,000)
Credit and Surety Business [Member]
Additional Information Related to Net Incurred Losses [Line Items]
Net favorable (adverse) prior year reserve development			7,000		19,000
Credit And Political Risk Insurance Business [Member]
Additional Information Related to Net Incurred Losses [Line Items]
Net favorable (adverse) prior year reserve development					(15,000)
Liability and Motor Reinsurance Business [Member]
Additional Information Related to Net Incurred Losses [Line Items]
Net favorable (adverse) prior year reserve development		$ 17,000	20,000	72,000	64,000
Liability Insurance Business [Member]
Additional Information Related to Net Incurred Losses [Line Items]
Net favorable (adverse) prior year reserve development			$ (6,000)		(23,000)
Retroactive Reinsurance Recoverable [Member]
Additional Information Related to Net Incurred Losses [Line Items]
Foreign exchange and other	$ 159,000
Catastrophe and Weather-related Events [Member]
Additional Information Related to Net Incurred Losses [Line Items]
Current year				$ 145,000	$ 90,000