Quarterly report pursuant to Section 13 or 15(d)

Financial Instruments (Details 1)

v3.7.0.1
Financial Instruments (Details 1) - USD ($)
$ in Thousands
Mar. 31, 2017
Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale Securities, Amortized Cost Basis $ 72,332 $ 93,129
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax 0 0
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax 55 39
Available-for-sale Securities 72,277 93,090
Cash and Cash Equivalents [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale Securities, Amortized Cost Basis 8,640 39,181
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax 0 0
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax 0 0
Available-for-sale Securities 8,640 39,181
Investments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale Securities, Amortized Cost Basis 63,692 53,948
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax 0 0
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax 55 39
Available-for-sale Securities 63,637 53,909
US Government Agencies Debt Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale Securities, Amortized Cost Basis 26,016 28,025
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax 0
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax 35 32
Available-for-sale Securities 25,981 27,993
Corporate Debt Securities [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale Securities, Amortized Cost Basis 37,676 25,923
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax 0 0
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax 20 7
Available-for-sale Securities 37,656 25,916
Money Market Funds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale Securities, Amortized Cost Basis 8,640 39,181
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax 0 0
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax 0 0
Available-for-sale Securities 8,640 39,181
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale Securities 72,277 93,090
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member] | Contingent Consideration [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Business Combination, Contingent Consideration, Liability, Noncurrent   375
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value Measurement [Member] | Money Market Funds [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale Securities $ 8,640 $ 39,181