Investments and Fair Value Measurements (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Amortized Cost		$ 24,455
Corporate Securities | Investments (current)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Amortized Cost	$ 12,425	$ 11,825
Corporate Securities | Investments (current) | Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held To Maturity Securities Maturity In Days	15 days	9 days
Corporate Securities | Investments (current) | Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held To Maturity Securities Maturity In Days	202 days	349 days
Corporate Securities | Investments (non-current)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities, Amortized Cost		$ 12,630
Corporate Securities | Investments (non-current) | Minimum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held To Maturity Securities Maturity In Days		380 days
Corporate Securities | Investments (non-current) | Maximum
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held To Maturity Securities Maturity In Days		567 days