Consolidated Statement of Stockholders' Equity - USD ($)	Total	Common Stock Outstanding	Paid-In Capital	Accumulated Other Comprehensive Income	Accumulated Other Comprehensive Income Foreign currency hedging derivatives:	Accumulated Other Comprehensive Income Interest rate swaps:	Treasury Stock	Retained Earnings
Beginning Balance (in shares) at Dec. 31, 2019		7,877,945
Beginning Balance at Dec. 31, 2019	$ 84,426,000	$ 79,000	$ 34,772,000	$ 1,370,000			$ (28,501,000)	$ 76,706,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	5,689,000							5,689,000
Change in post retirement benefits, net of tax	(125,000)			(125,000)
Gain (loss) on derivatives					$ (685,000)	$ (558,000)
Restricted stock vested (in shares)		87,344
Restricted stock vested	1,000	$ 1,000
Share-based compensation	704,000		704,000
Ending Balance (in shares) at Jun. 30, 2020		7,965,289
Ending Balance at Jun. 30, 2020	89,452,000	$ 80,000	35,476,000	2,000			(28,501,000)	82,395,000
Beginning Balance (in shares) at Mar. 31, 2020		7,882,716
Beginning Balance at Mar. 31, 2020	90,722,000	$ 79,000	35,088,000	(611,000)			(28,501,000)	84,667,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(2,272,000)							(2,272,000)
Change in post retirement benefits, net of tax	(63,000)			(63,000)
Gain (loss) on derivatives					$ 629,000	$ 47,000
Restricted stock vested (in shares)		82,573
Restricted stock vested	1,000	$ 1,000
Share-based compensation	388,000		388,000
Ending Balance (in shares) at Jun. 30, 2020		7,965,289
Ending Balance at Jun. 30, 2020	$ 89,452,000	$ 80,000	35,476,000	2,000			(28,501,000)	82,395,000
Beginning Balance (in shares) at Dec. 31, 2020	7,980,516	7,980,516
Beginning Balance at Dec. 31, 2020	$ 93,932,000	$ 80,000	36,127,000	1,375,000			(28,521,000)	84,871,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	7,542,000							7,542,000
Change in post retirement benefits, net of tax	(128,000)			(128,000)
Purchase of treasury stock	(47,000)						(47,000)
Restricted stock vested (in shares)		60,232
Restricted stock vested	0	$ 0
Share-based compensation	$ 804,000		804,000
Ending Balance (in shares) at Jun. 30, 2021	8,040,748	8,040,748
Ending Balance at Jun. 30, 2021	$ 102,103,000	$ 80,000	36,931,000	1,247,000			(28,568,000)	92,413,000
Beginning Balance (in shares) at Mar. 31, 2021		7,987,800
Beginning Balance at Mar. 31, 2021	97,595,000	$ 80,000	36,445,000	1,311,000			(28,568,000)	88,327,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	4,086,000							4,086,000
Change in post retirement benefits, net of tax	(64,000)			(64,000)
Restricted stock vested (in shares)		52,948
Restricted stock vested	0	$ 0
Share-based compensation	$ 486,000		486,000
Ending Balance (in shares) at Jun. 30, 2021	8,040,748	8,040,748
Ending Balance at Jun. 30, 2021	$ 102,103,000	$ 80,000	$ 36,931,000	$ 1,247,000			$ (28,568,000)	$ 92,413,000