Fair Value Measurements - Additional Information (Details) - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2020	Dec. 31, 2019	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Available-for-sale-investments in unrealized loss position, more than 12 months	$ 0	$ 0	$ 0
Other-than-temporary impairment losses recognized	0	0
Fair value, assets, level 1 to level 2 transfers, amount	0	0		$ 0
Fair value, assets, level 2 to level 1 transfers, amount	0	0		0
Fair value, liabilities, level 1 to level 2 transfers, amount	0	0		0
Fair value, liabilities, level 2 to level 1 transfers, amount	0	0		0
Fair value, assets, level 1 to level 3 transfers, amount	0	0		0
Fair value, assets, level 3 to level 1 transfers, amount	0	0		0
Fair value, liabilities, level 1 to level 3 transfers, amount	0	0		0
Fair value, liabilities, level 3 to level 1 transfers, amount	0	0		0
Fair value, assets, level 2 to level 3 transfers, amount	0	0		0
Fair value, assets, level 3 to level 2 transfers, amount	0	0		0
Fair value, liabilities, level 2 to level 3 transfers, amount	0	0		0
Fair value, liabilities, level 3 to level 2 transfers, amount	$ 0	$ 0		$ 0