INVESTMENTS (Net Realized Gains (Losses) by Major Investment Category (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract] (Deprecated 2018-01-31)
Gross realized and unrealized gains:	$ 2,311	$ 1,129	$ 5,458	$ 2,505
Gross realized and unrealized losses:	(356)	(921)	(1,202)	(3,349)
Net realized and unrealized gains (losses) on investments	1,955	208	4,256	(844)
Debt Securities
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract] (Deprecated 2018-01-31)
Gross realized and unrealized gains:	834	41	1,151	264
Gross realized and unrealized losses:	(120)	(877)	(520)	(2,318)
Equity Securities
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract] (Deprecated 2018-01-31)
Gross realized and unrealized gains:	1,477	1,088	4,307	2,241
Gross realized and unrealized losses:	$ (236)	$ (44)	$ (682)	$ (1,031)