INVESTMENTS Debt Securities and Common Stock (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019 USD ($) position security	Sep. 30, 2018 USD ($) security	Sep. 30, 2019 USD ($) position security	Sep. 30, 2018 USD ($) security
Securities in unrealized loss positions
Number of unrealized loss positions | position	171		171
Unrealized loss	$ 2,500		$ 2,500
Other-than-temporary impairment (OTTI) losses		$ 161		$ 217
Equity Securities, FV-NI, Unrealized Gain (Loss)	$ 4,906	$ 4,848	$ 47,214	$ (34,535)
Debt securities
Securities in unrealized loss positions
Number of unrealized loss positions | position	171		171
Number of securities in unrealized loss positions for 12 months or longer | security	79		79
Unrealized losses as percentage of fixed income portfolio cost basis	0.10%		0.10%
Number of securities with OTTI losses recognized in earnings | security		2		2
Other-than-temporary Impairment Loss, Debt Securities, Available-for-sale, Recognized in Earnings			$ 0	$ 200
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)	$ 6,900	$ 22,800	$ 61,700	$ (18,200)