CONSOLIDATED STATEMENTS OF OPERATIONS (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Net sales	$ 286,594		$ 295,121		$ 302,539
Costs and expenses:
Cost of sales	240,092		244,749		239,185
Selling, general and administrative	39,343		39,284		40,443
Litigation charges	26		3,471		8,103
Restructuring charges	5,245		314		0
Loss (gain) on disposal/sale of property, plant and equipment	183		(93)		(352)
Total costs and expenses	284,889		287,725		287,379
Income from operations	1,705		7,396		15,160
Impairment of investment	(775)		0		0
(Loss) gain on sale of investments	(142)		119		0
Interest expense	(16)		0		0
Interest income and other, net	266		357		420
Earnings before (benefit) provision for income taxes	1,038		7,872		15,580
(Benefit) provision for income taxes	(1,364)		4,108		1,931
Net earnings	2,402		3,764		13,649
Class A [Member]
Costs and expenses:
Net earnings	377		620		2,394
Earnings per share:
Common share - basic and diluted (in dollars per share)	$ 0.17	[1]	$ 0.28	[1]	$ 1.10
Weighted-average shares outstanding:
Common share - basic and diluted (in shares)	2,174,912		2,174,912		2,174,912
Dividends paid per share:
Common share (in dollars per share)	$ 0.24		$ 0.24		$ 0.24
Class B [Member]
Costs and expenses:
Net earnings	$ 2,025		$ 3,144		$ 11,255
Earnings per share:
Common share - basic and diluted (in dollars per share)	$ 0.21	[1]	$ 0.33	[1]	$ 1.18
Weighted-average shares outstanding:
Common share - basic and diluted (in shares)	9,624,578		9,597,661		9,504,261
Dividends paid per share:
Common share (in dollars per share)	$ 0.28		$ 0.28		$ 0.28

[1] Quarterly amounts of earnings per share may not agree to the total for the year due to rounding.