Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Assets
Collateral pledged	$ 1,295	$ 1,365
State tax credits held for sale	350	400
Payments of Debt Issuance Costs	$ 1,103	$ 1,136
Shareholders' equity:
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	5,000,000	5,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	30,000,000	30,000,000
Common stock, shares issued	23,867,710	23,781,112
Treasury stock, shares	756,588	691,673