INVESTMENTS (Gross Unrealized Losses and Related Fair Values for Available-For-Sale Debt Securities and Equity Securities, Grouped by Duration of Time in Continuous Unrealized Loss Position) (Details) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Fair value [Abstract]
Less than 12 months	$ 55,641	$ 154,742
12 months or longer	6,962	4,614
Total fair value	62,603	159,356
Gross unrealized losses [Abstract]
Less than 12 months	798	3,804
12 months or longer	226	145
Total gross unrealized losses	1,024	3,949
Debt securities [Member]
Fair value [Abstract]
Less than 12 months	50,051	142,952
12 months or longer	4,783	4,530
Total fair value	54,834	147,482
Gross unrealized losses [Abstract]
Less than 12 months	119	1,954
12 months or longer	56	139
Total gross unrealized losses	175	2,093
United States Government Obligations and Authorities [Member]
Fair value [Abstract]
Less than 12 months	8,995	30,464
12 months or longer	121	659
Total fair value	9,116	31,123
Gross unrealized losses [Abstract]
Less than 12 months	38	303
12 months or longer	1	17
Total gross unrealized losses	39	320
Obligations of States and Political Subdivisions [Member]
Fair value [Abstract]
Less than 12 months	28,481	16,652
12 months or longer	1,015
Total fair value	29,496	16,652
Gross unrealized losses [Abstract]
Less than 12 months	47	40
12 months or longer	2
Total gross unrealized losses	49	40
Corporate [Member]
Fair value [Abstract]
Less than 12 months	11,405	87,176
12 months or longer	3,345	3,590
Total fair value	14,750	90,766
Gross unrealized losses [Abstract]
Less than 12 months	33	1,420
12 months or longer	52	70
Total gross unrealized losses	85	1,490
International [Member]
Fair value [Abstract]
Less than 12 months	1,170	8,660
12 months or longer	302	281
Total fair value	1,472	8,941
Gross unrealized losses [Abstract]
Less than 12 months	1	191
12 months or longer	1	52
Total gross unrealized losses	2	243
Equity Securities [Member]
Fair value [Abstract]
Less than 12 months	5,590	11,790
12 months or longer	2,179	84
Total fair value	7,769	11,874
Gross unrealized losses [Abstract]
Less than 12 months	679	1,850
12 months or longer	170	6
Total gross unrealized losses	$ 849	$ 1,856