INVESTMENTS Debt and Short-term Investments (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017 USD ($) item	Sep. 30, 2016 USD ($)	Sep. 30, 2017 USD ($) item	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Other invested assets
Other investments	$ 25,998		$ 25,998		$ 24,115
Total tax benefit on investments in housing tax credit partnership	600	$ 400	1,900	$ 1,200
Investment in FHLBC	1,000		1,000		1,600
Federal Home Loan Bank Borrowings, Fair Value Disclosure	0		0
Cash and Short-term Investments
Cash	26,877	$ 13,970	26,877	$ 13,970	18,269	$ 11,081
Short-term investments, at cost which approximates fair value	$ 11,925		$ 11,925		5,015
Investment In Low Income Housing Tax Credit Partnership Net Of Amortization Member
Other invested assets
Number of investments in low income housing tax credit partnerships | item	3		3
Other investments	$ 16,000		$ 16,000		17,500
Investment in Federal Home Loan Bank Stock [Member]
Other invested assets
Available-for-sale Securities Pledged as Collateral	9,600		9,600		0
Investment in Real Estate Fund
Other invested assets
Other investments	3,100		3,100		5,000
Other investments fair value	3,100		3,100		$ 5,000
Investment in BDC
Other invested assets
Other investments fair value	6,000		6,000
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	19,100		19,100
Investment In Global Credit Fund
Other invested assets
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	$ 15,000		$ 15,000