INVESTMENTS Debt and Short-term Investments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Other invested assets
Other investments	$ 38,777		$ 38,777		$ 33,808
Investments pledged as collateral	$ 16,300		$ 16,300
Investment in Federal Home Loan Bank Stock	us-gaap:AssetPledgedAsCollateralMember		us-gaap:AssetPledgedAsCollateralMember
Federal Home Loan Bank Borrowings, Fair Value Disclosure	$ 0		$ 0
Cash and Short-term Investments
Cash	59,469		59,469		24,271
Short-term investments, at cost which approximates fair value	18,526		18,526		9,980
Investment In Low Income Housing Tax Credit Partnership Net Of Amortization Member
Other invested assets
Other investments	14,000		14,000		$ 15,500
Total tax benefit on investments in housing tax credit partnership	600	$ 600	1,700	$ 1,900
Qualified Affordable Housing Project Investments, Commitment	2,000		2,000
Investment in Private Funds [Member]
Other invested assets
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 25,200		$ 25,200