Fair Value Measurements (Details) - Measured at fair value on a recurring basis - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Cash equivalents
Total Cash equivalents	$ 78,493	$ 69,561
Short-term investments
Total Short-term investments	115,252	48,189
U.S. treasuries
Short-term investments
Total Short-term investments	105,130	37,184
Government agency securities
Short-term investments
Total Short-term investments	1,139
Corporate debt
Short-term investments
Total Short-term investments	6,002	8,516
Commercial paper
Short-term investments
Total Short-term investments	2,981	2,489
Certificate of deposits and time deposits
Cash equivalents
Total Cash equivalents	67,009	65,571
Commercial paper
Cash equivalents
Total Cash equivalents	10,484
Corporate debt
Cash equivalents
Total Cash equivalents	1,000
U.S. treasuries
Cash equivalents
Total Cash equivalents		3,990
Level 1
Cash equivalents
Total Cash equivalents	67,009	69,561
Short-term investments
Total Short-term investments	105,130	37,184
Level 1 | U.S. treasuries
Short-term investments
Total Short-term investments	105,130	37,184
Level 1 | Certificate of deposits and time deposits
Cash equivalents
Total Cash equivalents	67,009	65,571
Level 1 | U.S. treasuries
Cash equivalents
Total Cash equivalents		3,990
Level 2
Cash equivalents
Total Cash equivalents	11,484
Short-term investments
Total Short-term investments	10,122	11,005
Level 2 | Government agency securities
Short-term investments
Total Short-term investments	1,139
Level 2 | Corporate debt
Short-term investments
Total Short-term investments	6,002	8,516
Level 2 | Commercial paper
Short-term investments
Total Short-term investments	2,981	$ 2,489
Level 2 | Commercial paper
Cash equivalents
Total Cash equivalents	10,484
Level 2 | Corporate debt
Cash equivalents
Total Cash equivalents	$ 1,000