Fair Value of Assets and Liabilities (Details 4) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018 USD ($) Issurers_Currently_Performing	Dec. 31, 2017 USD ($) Issurers_Currently_Performing	Mar. 31, 2017 USD ($)
Additional information related to the Company's trust preferred securities
Available-for-sale Securities, Amortized Cost	$ 146,963	$ 164,683
Total debt securities, Fair Value	$ 141,717	$ 162,422
PreTSL XXIII | Moodys Ba1 Rating | Fitch CCC Rating
Additional information related to the Company's trust preferred securities
Class	C-2	C-2
Available-for-sale Securities, Amortized Cost	$ 758	$ 758
Total debt securities, Fair Value	448	336
Unrealized Gain/(Loss)	$ (310)	$ (422)
Number of Issuers Currently Performing | Issurers_Currently_Performing	90	90
Deferrals and Defaults as a % of Current Collateral	20.90%	20.90%
Excess Subordination as a % of Current Performing Collateral	7.12%	7.12%
Trapeza IX | Moodys Caa2 Rating | Fitch CC Rating
Additional information related to the Company's trust preferred securities
Class	B-1	B-1
Available-for-sale Securities, Amortized Cost	$ 860	$ 860
Total debt securities, Fair Value	642	559
Unrealized Gain/(Loss)	$ (218)	$ (301)
Number of Issuers Currently Performing | Issurers_Currently_Performing	30	30
Deferrals and Defaults as a % of Current Collateral	14.00%	14.00%
Trust preferred securities
Additional information related to the Company's trust preferred securities
Available-for-sale Securities, Amortized Cost	$ 1,618	$ 1,618
Total debt securities, Fair Value	1,090	895
Unrealized Gain/(Loss)	$ (528)	$ (723)	$ (723)