INVESTMENTS Debt Securities and Common Stock (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2018 USD ($) security position	Sep. 30, 2018 USD ($) security position	Sep. 30, 2017 USD ($) security
Securities in unrealized loss positions
Other-than-temporary impairment (OTTI) losses	$ 161	$ 217	$ 2,090
Equity Securities, FV-NI, Unrealized Gain (Loss)	$ 4,848	$ (34,535)
Debt securities
Securities in unrealized loss positions
Number of unrealized loss positions | position	676	676
Number of securities in unrealized loss positions for 12 months or longer | security	244	244
Unrealized losses as percentage of fixed income portfolio cost basis	2.00%	2.00%
Number of securities with OTTI losses recognized in earnings | security	2	2	2
Number of securities with OTTI losses recognized in earnings due to lack of intent to hold | security	1	1
Number of securities with OTTI losses recognized in earnings due to credit losses | security	1	1
Other-than-temporary Impairment Loss, Debt Securities, Available-for-sale, Recognized in Earnings		$ 200	$ 2,100
Other than Temporary Impairment Losses recognized in other comprehensive earnings		0	$ 0
Equity securities
Securities in unrealized loss positions
Equity Securities, FV-NI, Unrealized Gain (Loss)	$ 22,800	$ 18,200