RESERVE FOR LOSSES AND LOSS EXPENSES (DETAILS 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Net Favorable Prior Year Reserve Development [Line Items]
Net favorable prior year reserve development	$ 74,612	$ 51,550	$ 119,840	$ 101,254
Insurance [Member]
Net Favorable Prior Year Reserve Development [Line Items]
Net favorable prior year reserve development	35,394	26,754	50,289	41,481
Reinsurance [Member]
Net Favorable Prior Year Reserve Development [Line Items]
Net favorable prior year reserve development	$ 39,218	$ 24,796	$ 69,551	$ 59,773