Quarterly Financial Data (Narrative) (Details)	3 Months Ended
	Dec. 31, 2017 owners $ / shares	Sep. 30, 2017 $ / shares	Jun. 30, 2017 $ / shares	Mar. 31, 2017 $ / shares	Dec. 31, 2016 $ / shares	Sep. 30, 2016 $ / shares	Jun. 30, 2016 $ / shares	Mar. 31, 2016 $ / shares	Dec. 31, 2015 $ / shares	Sep. 30, 2015 $ / shares	Jun. 30, 2015 $ / shares	Mar. 31, 2015 $ / shares
Quarterly Financial Data [Abstract]
Restructuring charges, per share	$ 0.07	$ 0.11	$ 0.04	$ 0.05	$ 0.01	$ 0.01	$ 0.13	$ 0.01	$ 0.21	$ 0.07	$ 0.02	$ 0.18
Business acquistion adjustment decreased earing, per share					0.00	0.03
Costs related the acquisition transaction reduced earnings per share					0.00	0.00	0.08	0.03
Discrete income tax adjustments, per share	$ (0.21)	$ 0.12	$ (0.02)	$ (0.03)	$ 0.04	$ 0.00	$ 0.00	$ 0.03	$ 0.85	$ (0.15)	$ 0.00	(0.01)
Gain related to the sale of investment, per share												$ 0.02
Write-off of inventory (decreased)/increased earnings per share	1.00%	(6.00%)
Number of beneficial owners, including employees owning shares through the Company's 401(k) | owners	20,000
Earnings per share	$ 0.01