LOSS AND LOSS ADJUSTMENT EXPENSE RESERVES Reconciliation of the Net Incurred and Paid Claims Development (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Claims Development [Line Items]
Net outstanding liabilities	$ 438,830
Loss and loss adjustment expenses recoverable	27,531	$ 43,705
Add: Unallocated claims adjustment expenses	4,227
Total gross liabilities for unpaid claims and claim adjustment expense	470,588	482,662	$ 464,380	$ 306,641
Health
Claims Development [Line Items]
Net outstanding liabilities	18,063
Total gross liabilities for unpaid claims and claim adjustment expense	18,063	$ 24,502	$ 22,181	$ 18,993
Multiline
Claims Development [Line Items]
Net outstanding liabilities	148,768
General Liability
Claims Development [Line Items]
Net outstanding liabilities	12,349
Motor Liability
Claims Development [Line Items]
Net outstanding liabilities	105,172
Motor Property
Claims Development [Line Items]
Net outstanding liabilities	26,074
Other
Claims Development [Line Items]
Net outstanding liabilities	19,809
Property
Claims Development [Line Items]
Net outstanding liabilities	41,141
Professional Liability
Claims Development [Line Items]
Net outstanding liabilities	41,743
Workers' Compensation
Claims Development [Line Items]
Net outstanding liabilities	$ 25,711