Fair Value of Financial Instruments (Details) - Company’s financial assets measured at fair value - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value of Financial Instruments (Details) - Company’s financial assets measured at fair value [Line Items]
Financial Assets	$ 5,600	$ 2,607
Fair Value, Inputs, Level 1 [Member]
Fair Value of Financial Instruments (Details) - Company’s financial assets measured at fair value [Line Items]
Financial Assets	5,600	1,192
Fair Value, Inputs, Level 2 [Member]
Fair Value of Financial Instruments (Details) - Company’s financial assets measured at fair value [Line Items]
Financial Assets		1,415
Fair Value, Inputs, Level 3 [Member]
Fair Value of Financial Instruments (Details) - Company’s financial assets measured at fair value [Line Items]
Financial Assets
Money Market Funds [Member]
Fair Value of Financial Instruments (Details) - Company’s financial assets measured at fair value [Line Items]
Financial Assets	5,600	1,192
Money Market Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value of Financial Instruments (Details) - Company’s financial assets measured at fair value [Line Items]
Financial Assets	5,600	1,192
Money Market Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value of Financial Instruments (Details) - Company’s financial assets measured at fair value [Line Items]
Financial Assets
Money Market Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value of Financial Instruments (Details) - Company’s financial assets measured at fair value [Line Items]
Financial Assets
Corporate Bonds [Member]
Fair Value of Financial Instruments (Details) - Company’s financial assets measured at fair value [Line Items]
Financial Assets		1,415
Corporate Bonds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value of Financial Instruments (Details) - Company’s financial assets measured at fair value [Line Items]
Financial Assets
Corporate Bonds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value of Financial Instruments (Details) - Company’s financial assets measured at fair value [Line Items]
Financial Assets		1,415
Corporate Bonds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value of Financial Instruments (Details) - Company’s financial assets measured at fair value [Line Items]
Financial Assets