CONSOLIDATED STATEMENT OF INCOME (LOSS) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Income Statement [Abstract]
Net sales	$ 498,761	$ 548,341	$ 373,230
Cost of sales	340,015	369,356	236,281
Gross margin	158,746	178,985	136,949
Selling and administrative expenses	99,689	103,532	87,620
Research and development expenses	19,311	21,530	17,754
Restructuring Costs and Asset Impairment Charges	14,082	441	0
Operating income (loss)	25,664	53,482	31,575
Equity income in unconsolidated joint ventures	4,743	5,451	8,658
Other income (expense), net	(208)	1,942	1,364
Realized investment gain (loss):
Increase (decrease) in fair value of investments	(522)	(14)	1,271
Less: Portion reclassified to/from other comprehensive income	2,723	182	1,824
Net realized gain (loss)	(3,245)	(196)	(553)
Interest income (expense), net	(4,304)	(4,911)	184
Business Combination, Bargain Purchase, Gain Recognized, Amount	0	0	3,173
Income (loss) before income tax expense (benefit)	22,650	55,768	44,401
Income tax expense (benefit)	(46,484)	11,518	5,850
Income (loss) from continuing operations	69,134	44,250	38,551
Income (loss) from discontinued operations, net of income taxes	(449)	(7,195)	(3,980)
Net income (loss)	$ 68,685	$ 37,055	$ 34,571
Basic net income (loss) per share:
Income (loss) from continuing operations (in dollars per share)	$ 4.21	$ 2.76	$ 2.44
Income (loss) from discontinued operations	$ (0.03)	$ (0.45)	$ (0.25)
Net income (loss)	$ 4.18	$ 2.31	$ 2.19
Diluted net income (loss) per share:
Income (loss) from continuing operations (in dollars per share)	$ 4.07	$ 2.64	$ 2.41
Income (loss) from discontinued operations	$ (0.03)	$ (0.43)	$ (0.25)
Net income (loss)	$ 4.04	$ 2.21	$ 2.16
Shares used in computing:
Basic (in shares)	16,426,209	16,035,882	15,800,913
Diluted (in shares)	16,991,158	16,737,711	16,005,662