Fair Value Measurement (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Money Market Funds [Member]
Schedule of assets and liabilities measured at fair value on a recurring basis
Total assets at fair value on a recurring basis	$ 10,120	$ 5,103
Deferred payments [Member]
Liabilities:
Total liabilities at fair value on a recurring basis	12,066	11,741
Quoted Prices In Active Markets For Identical Assets/Liabilities (Level 1) [Member] | Money Market Funds [Member]
Schedule of assets and liabilities measured at fair value on a recurring basis
Total assets at fair value on a recurring basis	10,120	5,103
Significant Unobservable Inputs (Level 3) [Member] | Deferred payments [Member]
Liabilities:
Total liabilities at fair value on a recurring basis	$ 12,066	$ 11,741