RESERVE FOR LOSSES AND LOSS EXPENSES (Details 3) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Net Favorable Prior Year Reserve Development [Line Items]
Net favorable prior year reserve development	$ 70,933	$ 77,719	$ 95,727	$ 148,113
Insurance [Member]
Net Favorable Prior Year Reserve Development [Line Items]
Net favorable prior year reserve development	19,517	20,066	28,137	22,493
Reinsurance [Member]
Net Favorable Prior Year Reserve Development [Line Items]
Net favorable prior year reserve development	$ 51,416	$ 57,653	$ 67,590	$ 125,620