CONDENSED CONSOLIDATED STATEMENTS OF INCOME (LOSS) (USD $)
In Thousands, except Share data, unless otherwise specified
3 Months Ended
Mar. 31, 2015
Mar. 31, 2014
Income Statement [Abstract]    
Net sales $ 165,051 $ 146,640
Cost of sales 102,696 92,721
Gross margin 62,355 53,919
Selling and administrative expenses 36,147 27,599
Research and development expenses 6,108 4,863
Operating income 20,100 21,457
Equity income in unconsolidated joint ventures 919 977
Other income (expense), net (129) (1,191)
Interest income (expense), net (1,006) (748)
Income before income tax expense 19,884 20,495
Income tax expense 6,257 5,915
Net income (loss) $ 13,627 $ 14,580
Basic earnings per share (in dollars per share) $ 0.74 $ 0.81
Diluted earnings per share (in dollars per share) $ 0.72 $ 0.79
Shares used in computing:    
Basic net income per share (shares) 18,475,507 17,950,843
Diluted net income per share (shares) 18,949,594 18,549,458