Fair Value Measurements - Assets and Liabilities Carried at Fair Value Measured on Recurring Basis (Detail) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Assets:
Cash equivalents	$ 125,048	$ 23,538
Total cash equivalents	125,048	23,538
Quoted Prices in Active Markets (Level 1) [Member]
Assets:
Cash equivalents	125,048	23,538
Total cash equivalents	125,048	23,538
Significant Other Observable Inputs (Level 2) [Member]
Assets:
Cash equivalents	0	0
Total cash equivalents	0	0
Significant Unobservable Inputs (Level 3) [Member]
Assets:
Cash equivalents	0	0
Total cash equivalents	$ 0	$ 0