REINSURANCE (Premiums Written and Earned) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Net Premiums Written
Direct									$ 610,608	$ 567,764	$ 603,417
Ceded									(232,729)	(202,732)	(260,524)
Net premiums written									377,879	365,032	342,893
Net Premiums Earned
Direct									582,334	580,020	603,193
Ceded									(218,682)	(224,763)	(269,712)
Net premiums earned	$ 95,188	$ 87,374	$ 92,306	$ 88,784	$ 91,098	$ 98,493	$ 83,557	$ 82,109	$ 363,652	$ 355,257	$ 333,481