INVESTMENTS Debt and Short-term Investments (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($) item	Mar. 31, 2016 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Other invested assets
Other investments	$ 24,199		$ 24,115
Total tax benefit on investments in housing tax credit partnership	600	$ 400
Investment in FHLBC	800		1,600
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share, Unfunded Commitments	23,600
Cash and Short-term Investments
Cash	28,144	$ 14,569	18,269	$ 11,081
Short-term investments, at cost which approximates fair value	$ 13,002		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
Other investments	$ 17,000		17,500
Investment in Real Estate Fund
Other invested assets
Other investments	3,100		5,000
Other investments fair value	3,100		$ 5,000
Investment in BDC
Other invested assets
Other investments fair value	$ 3,300