Fair Value Measurements - Fair Value Inputs, Liabilities, Quantitative Information (Details) - Contingent Consideration - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Dec. 31, 2013
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Contingent consideration liability	$ 2,147	$ 1,949	$ 1,886	$ 1,717	$ 2,507	$ 2,526
Revenue-based Payments
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Contingent consideration liability	$ 1,999
Revenue-based Payments | Minimum | Income Approach Valuation Technique | Fair Value, Inputs, Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Discount rate	5.00%
Probability of milestone payment	15.00%
Revenue-based Payments | Maximum | Income Approach Valuation Technique | Fair Value, Inputs, Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Discount rate	15.00%
Probability of milestone payment	100.00%
Other Payments
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Contingent consideration liability	$ 148
Other Payments | Income Approach Valuation Technique | Fair Value, Inputs, Level 3
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Discount rate	5.00%
Probability of milestone payment	100.00%