Unaudited Condensed Consolidated Statements of Changes in Equity (USD $) In Thousands, unless otherwise specified	Total	Total Stockholders' Equity	Common Stock Shares Outstanding Class A	Common Stock Shares Outstanding Class B	Capital in Excess of Par Value	Retained Earnings	Foreign Currency Translation Adjustment	Deferred Gain (Loss) on Available for Sale Securities	Deferred Gain (Loss) on Cash Flow Hedging	Pension and Postretirement Plan Adjustment
Balance, beginning of period at Dec. 31, 2013		$ 297,780	$ 6,290	$ 1,581	$ 941	$ 301,227	$ (803)	$ 1,021	$ 676	$ (13,153)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation		417	19		398
Purchase of treasury shares		(4,986)	(91)		(1,339)	(3,556)
Net income (loss)	(1,524)	(1,524)				(1,524)
Cash dividends on Class A and Class B common stock: $0.2575 per share		(1,964)	0	0		(1,964)
Current period other comprehensive income (loss)		(518)					(174)	63	(407)	0
Reclassification adjustment to net income (loss)		338							180	158
Balance, end of period at Mar. 31, 2014		289,543	6,218	1,581	0	294,183	(977)	1,084	449	(12,995)
Balance, beginning of period at Dec. 31, 2014		211,474	5,662	1,573	0	224,428	(2,699)	1,463	56	(19,009)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation		146	34		112
Purchase of treasury shares		(6,911)	(121)		(112)	(6,678)
Net income (loss)	1,027	1,027				1,027
Cash dividends on Class A and Class B common stock: $0.2575 per share		(1,850)				(1,850)
Current period other comprehensive income (loss)		(1,380)					(823)	38	(595)	0
Reclassification adjustment to net income (loss)		444							185	259
Balance, end of period at Mar. 31, 2015		$ 202,950	$ 5,575	$ 1,573	$ 0	$ 216,927	$ (3,522)	$ 1,501	$ (354)	$ (18,750)