SCHEDULE IV - REINSURANCE (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
SEC Schedule, 12-17, Insurance Companies, Reinsurance [Abstract]
Gross Amount	$ 1,155,240	$ 1,084,748	$ 1,059,973
Ceded to Other Companies	129,337	111,391	125,735
Assumed From Other Companies	5,085	1,805	509
Net Amount	$ 1,030,988	$ 975,162	$ 934,747
Percentage of Amount Assumed to Net	0.50%	0.20%	0.10%