CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Thousands, shares in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue:
Product revenue	$ 957,800	$ 857,500	$ 811,800
Service revenue	149,500	126,700	122,400
Total revenue	1,107,300	984,200	934,200
Operating expenses:
Cost of products	676,200	625,700	606,400
Cost of services	114,200	93,800	92,600
Selling, general and administrative expense	207,000	183,300	166,600
Research and development expense	18,200	14,600	14,000
Restructuring expense	0	14,500	1,600
Other (income) expense, net	2,700	1,600	(200)
Operating income:	89,000	50,700	53,200
Interest income	1,100	1,600	2,200
Interest expense	(7,900)	(7,600)	(7,600)
Income from continuing operations before income taxes	82,200	44,700	47,800
Provision for income taxes	26,200	13,900	13,800
Income from continuing operations	56,000	30,800	34,000
Loss from discontinued operations, net of income taxes	(100)	0	(900)
Net income	$ 55,900	$ 30,800	$ 33,100
Basic earnings per share:
Income from continuing operations (in Dollars per share)	$ 1.90	$ 1.04	$ 1.16
Loss from discontinued operations (in Dollars per share)	(0.01)	0.00	(0.03)
Net income (in Dollars per share)	1.89	1.04	1.13
Diluted earnings per share:
Income from continuing operations (in Dollars per share)	1.88	1.03	1.15
Loss from discontinued operations (in Dollars per share)	0.00	0.00	(0.04)
Net income (in Dollars per share)	1.88	1.03	1.11
Dividends declared per share (in Dollars per share)	$ 0.37	$ 0.36	$ 0.34
Weighted average shares outstanding:
Basic (in Shares)	29.5	29.5	29.2
Diluted (in Shares)	29.8	29.9	29.7