Net (loss) income per share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Jun. 30, 2018	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
Earnings Per Share Reconciliation [Abstract]
Net (loss) income from continuing operations	$ (16,704)	$ (1,517)	$ (17,959)	$ 1,724
Basic:
Shares outstanding at beginning of period (in shares)					15,993,000	15,949,000	15,907,000	15,771,000
Weighted average shares issued during the period, net (in shares)	78,000	69,000	84,000	178,000
Weighted average common shares, basic (in shares)	16,071,000	15,976,000	16,033,000	15,949,000
Net (loss) income from continuing operations per common share, basic (in dollars per shares)	$ (1.04)	$ (0.10)	$ (1.12)	$ 0.11
Diluted:
Weighted average common shares, basic (in shares)	16,071,000	15,976,000	16,033,000	15,949,000
Dilutive impact of stock options and restricted stock awards (in shares)	0	0	0	311,000
Weighted average common shares, diluted (in shares)	16,071,000	15,976,000	16,033,000	16,260,000
Net (loss) income from continuing operations per common share, diluted (in dollars per share)	$ (1.04)	$ (0.10)	$ (1.12)	$ 0.11
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive stock options outstanding (in shares)			0	0