Marketable Securities (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Dec. 31, 2016
Schedule of Available-for-sale Securities [Line Items]
Term of maturities of investments considered short-term	2 years
Short-term marketable securities
Schedule of Available-for-sale Securities [Line Items]
Total marketable securities	$ 7,982	$ 10,308
Corporate and government bonds and notes, and commercial paper | Short-term marketable securities
Schedule of Available-for-sale Securities [Line Items]
Total marketable securities	7,982	10,230
Certificates of deposit | Short-term marketable securities
Schedule of Available-for-sale Securities [Line Items]
Total marketable securities	$ 0	$ 78