RESERVE FOR LOSSES AND LOSS EXPENSES (DETAILS) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Insurance Loss Reserves [Abstract]
Reserve for reported losses and loss expenses	$ 3,499,817	$ 3,272,682
Reserve for losses incurred but not reported	6,082,323	5,786,049
Reserve for losses and loss expenses	$ 9,582,140	$ 9,058,731	$ 8,425,045	$ 7,032,375