Fair Value Measurements - Summary of Financial Assets that are Measured at Fair Value on a Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Assets:
Total cash equivalents	$ 380,532	$ 364,127
Level 1
Assets:
Total cash equivalents	380,532	364,127
Money Market Funds
Assets:
Total cash equivalents	380,532	364,127
Money Market Funds | Level 1
Assets:
Total cash equivalents	$ 380,532	$ 364,127