SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Deferred Policy Acquisition Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Recorded asset at beginning of year	$ 168,264	$ 139,719	$ 150,092
Underwriting costs deferred	211,271	203,982	173,865
Amortization of deferred policy acquisition costs	(211,013)	(186,817)	(167,449)
Ending unamortized deferred policy acquisition costs	168,522	156,884	156,508
Change in shadow deferred policy acquisition costs	(4,410)	11,380	(16,789)
Recorded asset at end of year	164,112	168,264	139,719
Property and Casualty Insurance
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Recorded asset at beginning of year	90,547	72,861	67,663
Underwriting costs deferred	205,707	197,869	166,508
Amortization of deferred policy acquisition costs	(202,892)	(180,183)	(161,310)
Recorded asset at end of year	93,362	90,547	72,861
Life Insurance
Movement Analysis of Deferred Policy Acquisition Costs [Roll Forward]
Recorded asset at beginning of year	77,717	66,858	82,429
Underwriting costs deferred	5,564	6,113	7,357
Amortization of deferred policy acquisition costs	(8,121)	(6,634)	(6,139)
Ending unamortized deferred policy acquisition costs	75,160	66,337	83,647
Change in shadow deferred policy acquisition costs	(4,410)	11,380	(16,789)
Recorded asset at end of year	$ 70,750	$ 77,717	$ 66,858