DERIVATIVE INSTRUMENTS (DETAILS 3) (Not Designated as Hedging Instruments [Member], USD $) In Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Unrealized and Realized Gains (Losses) Recognized in Earnings for Derivatives Not Designated As Hedges [Line Items]
Unrealized and realized gains (losses) recognized in earnings for derivatives not designated as hedges	$ 13,091	$ (9,044)	$ 24,558	$ 1,202
Currency Collar Options [Member] | Underwriting Portfolio [Member] | Foreign Exchange Gains (Losses) [Member]
Unrealized and Realized Gains (Losses) Recognized in Earnings for Derivatives Not Designated As Hedges [Line Items]
Unrealized and realized gains (losses) recognized in earnings for derivatives not designated as hedges	(2,975)	0	352	0
Foreign Exchange Contracts [Member] | Investment Portfolio [Member] | Net Realized Investment Gains (Losses) [Member]
Unrealized and Realized Gains (Losses) Recognized in Earnings for Derivatives Not Designated As Hedges [Line Items]
Unrealized and realized gains (losses) recognized in earnings for derivatives not designated as hedges	18,825	(6,333)	5,364	(3,503)
Foreign Exchange Contracts [Member] | Underwriting Portfolio [Member] | Foreign Exchange Gains (Losses) [Member]
Unrealized and Realized Gains (Losses) Recognized in Earnings for Derivatives Not Designated As Hedges [Line Items]
Unrealized and realized gains (losses) recognized in earnings for derivatives not designated as hedges	$ (2,759)	$ (2,711)	$ 18,842	$ 4,705