Business Acquisition Business Combination Text(Details) $ in Thousands, € in Millions, AUD in Millions					9 Months Ended		12 Months Ended
	Feb. 01, 2016 USD ($) $ / AUD	Feb. 01, 2016 AUD	Jan. 15, 2015 USD ($) $ / €	Jan. 15, 2015 EUR (€)	Sep. 30, 2017 USD ($)	Sep. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)	Feb. 01, 2016 AUD $ / AUD	Jan. 15, 2015 EUR (€) $ / €
Business Acquisition [Line Items]
Contingent Consideration Period Change in Valuation, Interest					$ 100		$ 300
Contingent Consideration Period Change in Valuation, Estimate Adjustment					(100)		(200)
Contingent Consideration Payment					2,589	$ 669	669
ExacAustralia [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition	Feb. 01, 2016	Feb. 01, 2016
Business Acquisition, Percentage of Voting Interests Acquired	100.00%							100.00%
Business Combination, Consideration Transferred	$ 1,100	AUD 1.6
Foreign Currency Exchange Rate, Translation | $ / AUD	0.7034							0.7034
Contingent Consideration Payment					1,206		0
Business Combination, Consideration Transferred, Other	$ 2,000
Fair Value Inputs, Discount Rate	3.70%	3.70%
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets	$ 2,700
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities	(400)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	500
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net	$ 2,800
Blue Ortho [Member]
Business Acquisition [Line Items]
Business Acquisition, Effective Date of Acquisition			Jan. 15, 2015	Jan. 15, 2015
Business Acquisition, Percentage of Voting Interests Acquired			100.00%						100.00%
Business Combination, Consideration Transferred			$ 2,300	€ 2.0
Foreign Currency Exchange Rate, Translation | $ / €			1.16						1.16
Contingent Consideration Payment					$ 1,383		$ 669
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets			$ 1,500
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities			(2,900)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles			7,500
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net			$ 6,500
Minimum [Member] | ExacAustralia [Member]
Business Acquisition [Line Items]
Business Combination Consideration Recognized | AUD								AUD 3.1
Maximum | ExacAustralia [Member]
Business Acquisition [Line Items]
Business Combination Consideration Recognized | AUD								AUD 7.6
Maximum | Blue Ortho [Member]
Business Acquisition [Line Items]
Business Combination Consideration Recognized | €									€ 10.0