Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands	Total	No Par, Common Stock	Accumulated deficit	Accumulated Other Comprehensive Income (Loss)	Private placement	Private placement No Par, Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adoption of ASU No. 2016-01, net of taxes | Accounting Standards Update 2016-01				$ 0
Balance at beginning of period (in shares) at Dec. 31, 2016		7,633,070
Balance at beginning of period at Dec. 31, 2016	$ 67,794	$ 80,342	$ (11,468)	(1,080)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(1,798)		(1,798)
Restricted stock unit expense, net (in shares)		(1)
Restricted stock unit expense, net	243	$ 243
Other comprehensive loss	334			334
Balance at end of period (in shares) at Mar. 31, 2017		7,633,069
Balance at end of period at Mar. 31, 2017	66,573	$ 80,585	(13,266)	(746)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(19,744)		(19,744)
Restricted stock unit expense, net (in shares)		87,259
Restricted stock unit expense, net	652	$ 652
Other comprehensive loss	383			383
Issuance of common stock in private placement (in shares)						800,000
Issuance of common stock in private placement					$ 5,000	$ 5,000
Common stock issuance costs	(38)	$ (38)
Balance at end of period (in shares) at Dec. 31, 2017		8,520,328
Balance at end of period at Dec. 31, 2017	52,826	$ 86,199	(33,010)	(363)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adoption of ASU No. 2016-01, net of taxes | Accounting Standards Update 2016-01	0		556	(556)
Net income (loss)	213		213
Restricted stock unit expense, net (in shares)		0
Restricted stock unit expense, net	231	$ 231
Other comprehensive loss	(1,846)			(1,846)
Common stock issuance costs		$ 0
Cumulative effect of adoption of ASU No. 2018-02, net of taxes	0		(77)	77
Balance at end of period (in shares) at Mar. 31, 2018		8,520,328
Balance at end of period at Mar. 31, 2018	$ 51,424	$ 86,430	$ (32,318)	$ (2,688)