Pension Plan (Details) - Presentation of the non-service components of periodic pension cost to Pension benefit - Accounting Standards Update 2017-07 [Member] - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2017
Error Corrections and Prior Period Adjustments Restatement [Line Items]
General and administrative expenses	$ 1,521	$ 4,380
Operating income (loss)	138	(2,051)
Pension benefit	(9)	(26)
Loss before income taxes	(123)	(2,632)
Previously Reported [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
General and administrative expenses	1,512	4,354
Operating income (loss)	147	(2,025)
Pension benefit
Loss before income taxes	(123)	(2,632)
Restatement Adjustment [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
General and administrative expenses	9	26
Operating income (loss)	(9)	(26)
Pension benefit	(9)	(26)
Loss before income taxes