Condensed Consolidated Statements of Changes in Stockholders' Equity - USD ($)		Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock, Common [Member]	Accumulated Foreign Currency Adjustment Attributable to Parent [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common Stock, Shares, Outstanding		8,955,930
Common Stock Outstanding, $1 Par Value		$ 9,006,000
Capital in Excess of Par Value		15,623,000
Retained Earnings		77,338,000
Treasury Stock		(1,234,000)
Accumulated Other Comprehensive Income (Loss)		(1,560,000)
Total Stockholders' Equity		99,173,000
Net income		4,146,000			$ 4,146,000
Adjustment for foreign currency translation		675,000					$ 675,000
Stock-based compensation		$ 666,000		$ 666,000
Shares issued (in shares)		6,520
Shares issued		$ 0	$ 6,000	(6,000)
Net income		10,227,000
Adjustment for foreign currency translation		$ 965,000
Common Stock, Shares, Outstanding		8,962,450
Common Stock Outstanding, $1 Par Value		$ 9,012,000
Capital in Excess of Par Value		16,283,000
Retained Earnings		83,421,000
Treasury Stock		(1,234,000)
Accumulated Other Comprehensive Income (Loss)		(885,000)
Total Stockholders' Equity		106,597,000
Change in accounting principle	[1]	1,937,000			1,937,000
Net income		1,307,000			1,307,000
Adjustment for foreign currency translation		717,000					717,000
Stock-based compensation		$ 711,000		711,000
Shares issued (in shares)		20,712
Shares issued		$ 0	21,000	(21,000)
Common Stock, Shares, Outstanding		8,983,162
Common Stock Outstanding, $1 Par Value		$ 9,033,000
Capital in Excess of Par Value		16,973,000
Retained Earnings		84,728,000
Treasury Stock		(1,234,000)
Accumulated Other Comprehensive Income (Loss)		(168,000)
Total Stockholders' Equity		109,332,000
Net income		$ 4,774,000			4,774,000
Treasury shares repurchased (in shares)		(35,830)
Treasury shares repurchased		$ (1,361,000)
Adjustment for foreign currency translation		(427,000)					(427,000)
Stock-based compensation		$ 663,000		663,000
Shares issued (in shares)		9,649
Shares issued		$ 0	10,000	(10,000)
Common Stock, Shares, Outstanding		8,956,981
Common Stock Outstanding, $1 Par Value		$ 9,043,000
Capital in Excess of Par Value		17,626,000
Retained Earnings		89,502,000
Treasury Stock		(2,595,000)
Accumulated Other Comprehensive Income (Loss)		(595,000)
Total Stockholders' Equity		$ 112,981,000
Common Stock, Shares, Outstanding		9,043,771
Common Stock Outstanding, $1 Par Value		$ 9,190,000
Capital in Excess of Par Value		18,077,000
Retained Earnings		86,496,000
Treasury Stock		(5,761,000)
Accumulated Other Comprehensive Income (Loss)		(1,000)
Total Stockholders' Equity		108,001,000
Net income		$ 12,533,000			12,533,000
Treasury shares repurchased (in shares)		(47,504)
Treasury shares repurchased		$ (1,756,000)				$ (1,756,000)
Adjustment for foreign currency translation		(2,494,000)					(2,494,000)
Stock-based compensation		451,000		451,000
Net income		$ 14,890,000
Treasury shares repurchased (in shares)		(47,504)
Adjustment for foreign currency translation		$ (918,000)
Common Stock, Shares, Outstanding		8,996,267
Common Stock Outstanding, $1 Par Value		$ 9,190,000
Capital in Excess of Par Value		18,528,000
Retained Earnings		99,029,000
Treasury Stock		(7,517,000)
Accumulated Other Comprehensive Income (Loss)		(2,495,000)
Total Stockholders' Equity		116,735,000
Net income		619,000			619,000
Adjustment for foreign currency translation		1,178,000					1,178,000
Stock-based compensation		$ 498,000		498,000
Shares issued (in shares)		11,144
Shares issued		$ 14,000	11,000	3,000
Common Stock, Shares, Outstanding		9,007,411
Common Stock Outstanding, $1 Par Value		$ 9,201,000
Capital in Excess of Par Value		19,029,000
Retained Earnings		99,648,000
Treasury Stock		(7,517,000)
Accumulated Other Comprehensive Income (Loss)		(1,317,000)
Total Stockholders' Equity		119,044,000
Net income		$ 1,738,000			$ 1,738,000
Treasury shares repurchased (in shares)		(12,077)
Treasury shares repurchased		$ (436,000)
Adjustment for foreign currency translation		398,000					$ 398,000
Stock-based compensation		$ 510,000		510,000
Shares issued (in shares)		30,283
Shares issued		$ 0	$ 31,000	$ (31,000)
Common Stock, Shares, Outstanding		9,025,617
Common Stock Outstanding, $1 Par Value		$ 9,232,000
Capital in Excess of Par Value		19,508,000
Retained Earnings		101,386,000
Treasury Stock		(7,953,000)
Accumulated Other Comprehensive Income (Loss)		(919,000)
Total Stockholders' Equity		$ 121,254,000

[1] The Company adopted the ASC No.842, Leases (ASC 842) on January 1, 2019 using the modified retrospective approach. See Note 7 - Leases for further details.