INVESTMENTS Debt Securities and Common Stock (Details) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019 USD ($) security position	Jun. 30, 2018 USD ($) security	Jun. 30, 2019 USD ($) security position	Jun. 30, 2018 USD ($) security
Securities in unrealized loss positions
Number of unrealized loss positions | position	279		279
Unrealized loss	$ 3,600		$ 3,600
Other-than-temporary impairment (OTTI) losses				$ 56
Equity Securities, FV-NI, Unrealized Gain (Loss)	$ 8,810	$ (12,611)	$ 42,308	$ (39,383)
Debt securities
Securities in unrealized loss positions
Number of unrealized loss positions | position	279		279
Number of securities in unrealized loss positions for 12 months or longer | security	122		122
Unrealized losses as percentage of fixed income portfolio cost basis	0.20%		0.20%
Number of securities with OTTI losses recognized in earnings | security		1		1
Other-than-temporary Impairment Loss, Debt Securities, Available-for-sale, Recognized in Earnings			$ 0	$ 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)	$ 12,900	$ 9,100	$ 54,800	$ (4,800)