Quarterly report pursuant to Section 13 or 15(d)

Financial Instruments Financial Instruments - Additional Information (Details 4)

v3.3.0.814
Financial Instruments Financial Instruments - Additional Information (Details 4)
 9 Months Ended 12 Months Ended
Sep. 30, 2015
USD ($)
debt_security
Dec. 31, 2014
USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value, Assets, Level 1 to Level 2 Transfers, Amount $ 0  
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | debt_security 7  
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value $ 11,100,000  
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax 6,000 $ 50,000
Fair Value, Assets, Level 2 to Level 1 Transfers, Amount 0  
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net $ 0  
Minimum [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available For Sale Securities Non Current Maturity Period 1 year  
Minimum [Member] | Fair Value, Inputs, Level 3 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value Inputs, Discount Rate 0.77% 0.54%
Maximum [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Period Of Unrealized Loss Position 12 months  
Available For Sale Securities Non Current Maturity Period 2 years  
Maximum [Member] | Fair Value, Inputs, Level 3 [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Fair Value Inputs, Discount Rate 0.38% 0.33%
Investments [Member]    
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]    
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax $ 6,000 $ 50,000