CONDENSED CONSOLIDATED STATEMENT OF INCOME (LOSS) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Net sales	$ 125,979	$ 120,155
Cost of sales	84,690	83,751
Gross margin	41,289	36,404
Selling and administrative expenses	25,206	24,239
Research and development expenses	5,269	5,323
Restructuring and impairment charges		7,349
Operating income (loss)	10,814	(507)
Equity income in unconsolidated joint ventures	529	657
Other income (expense), net	(589)	(140)
Realized investment gain (loss):
Increase (decrease) in fair value of investments		(522)
Less: Portion reclassified to/from other comprehensive income		2,723
Net realized gain (loss)		(3,245)
Interest income (expense), net	(905)	(1,190)
Income (loss) before income tax expense (benefit)	9,849	(4,425)
Income tax expense (benefit)	2,873	(2,839)
Income (loss) from continuing operations	6,976	(1,586)
Income (loss) from discontinued operations, net of income taxes	120	(222)
Net income (loss)	$ 7,096	$ (1,808)
Basic net income (loss) per share:
Income (loss) from continuing operations (in dollars per share)	$ 0.41	$ (0.10)
Income (loss) from discontinued operations	$ 0.01	$ (0.01)
Net income (loss)	$ 0.42	$ (0.11)
Diluted net income (loss) per share:
Income (loss) from continuing operations (in dollars per share)	$ 0.39	$ (0.10)
Income (loss) from discontinued operations	$ 0.01	$ (0.01)
Net income (loss)	$ 0.40	$ (0.11)
Shares used in computing:
Basic (in shares)	17,072,459	16,232,856
Diluted (in shares)	17,673,399	16,232,856