Marketable Securities - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Marketable Securities [Line Items]
Marketable securities	$ 383,300,000		$ 383,300,000		$ 405,600,000
Marketable securities unrealized loss, Less than twelve months	917,800,000		917,800,000		1,311,600,000
Marketable securities unrealized loss, more than twelve months	78,500,000		78,500,000		4,600,000
Marketable securities totaling	8,392,000		8,392,000		$ 0.0
Available-for-sale debt securities remaining maturities greater than thirty months	0		0
Other Comprehensive Income (Loss) [Member]
Marketable Securities [Line Items]
Unrealized loss, net	$ 3,400,000	$ 200,000	$ 15,200,000	$ 600,000