Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Statement [Abstract]
Net sales	$ 860,661	$ 794,059	$ 752,148
Cost of sales	448,211	435,140	410,118
Gross profit	412,450	358,919	342,030
Operating expenses:
Research and development and other engineering	46,248	46,196	39,018
Selling	98,343	90,663	92,031
General and administrative	129,162	113,428	111,500
Impairment of goodwill	0	0	530
Net gain on disposal of assets	(780)	(389)	(325)
Total operating expenses	272,973	249,898	242,754
Income from operations	139,477	109,021	99,276
Interest income	570	655	901
Interest expense	(1,147)	(997)	(855)
Income before taxes	138,900	108,679	99,322
Provision for income taxes	49,166	40,791	35,791
Net income	$ 89,734	$ 67,888	$ 63,531
Earnings per common share:
Basic (in USD per share)	$ 1.87	$ 1.39	$ 1.30
Diluted (in USD per share)	$ 1.86	$ 1.38	$ 1.29
Weighted average number of shares outstanding
Basic (in shares)	48,084	48,952	48,977
Diluted (in shares)	48,295	49,181	49,194

The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use; (3) to conduct internal product testing; (4) or to provide engineering support to customers in the form of testing services or product uses, specifications or requirements.

No definition available.