CONDENSED CONSOLIDATED STATEMENT OF INCOME (LOSS) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Net sales	$ 132,452	$ 125,295	$ 258,432	$ 245,450
Cost of sales	88,023	88,641	172,713	172,392
Gross margin	44,429	36,654	85,719	73,058
Selling and administrative expenses	25,547	22,329	50,753	46,568
Research and development expenses	6,250	4,474	11,519	9,797
Restructuring and impairment charges	4,525	834	4,525	8,183
Operating income (loss)	8,107	9,017	18,922	8,510
Equity income in unconsolidated joint ventures	762	1,305	1,291	1,962
Other income (expense), net	(177)	261	(766)	121
Realized investment gain (loss):
Increase (decrease) in fair value of investments	0	0	0	(522)
Less: Portion reclassified to/from other comprehensive income	0	0	0	2,723
Net realized gain (loss)	0	0	0	(3,245)
Interest income (expense), net	(830)	(1,072)	(1,735)	(2,262)
Income (loss) before income tax expense (benefit)	7,862	9,511	17,712	5,086
Income tax expense (benefit)	2,279	3,094	5,152	255
Income (loss) from continuing operations	5,583	6,417	12,560	4,831
Income (loss) from discontinued operations, net of income taxes	(18)	38	102	(185)
Net income (loss)	$ 5,565	$ 6,455	$ 12,662	$ 4,646
Basic net income (loss) per share:
Income (loss) from continuing operations (in dollars per share)	$ 0.33	$ 0.40	$ 0.73	$ 0.29
Income (loss) from discontinued operations (in dollars per share)	$ 0.00	$ 0.00	$ 0.01	$ (0.01)
Net income (loss) (in dollars per share)	$ 0.33	$ 0.40	$ 0.74	$ 0.28
Diluted net income (loss) per share:
Income (loss) from continuing operations (in dollars per share)	$ 0.32	$ 0.38	$ 0.71	$ 0.28
Income (loss) from discontinued operations (in dollars per share)	$ 0.00	$ 0.00	$ 0.01	$ (0.01)
Net income (loss) (in dollars per share)	$ 0.32	$ 0.38	$ 0.72	$ 0.27
Shares used in computing:
Basic (in shares)	17,107,727	16,309,053	17,090,093	16,270,955
Diluted (in shares)	17,599,481	16,864,166	17,636,440	16,842,768