Stockholders' Equity - Narrative (Detail) $ / shares in Units, $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended
	Feb. 28, 2022 USD ($) alternative	Jun. 30, 2022 USD ($) agreement $ / shares shares	Jun. 30, 2021 USD ($) shares	Jun. 30, 2022 USD ($) agreement $ / shares shares	Jun. 30, 2021 USD ($) shares
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units, approved (in shares) | shares				794,013
Weighted-average grant date fair value (in dollars per share) | $ / shares				$ 663.94
Requisite service period (in years)				3 years 6 months 3 days
2020 ATM Program and Equity Forward Amendment
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Sale of stock, equity offering agreement, authorized	$ 1,500.0
Number of settlement alternatives | alternative	3
Equity Forward Amendment
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of forward sale agreements | agreement		5		5
Sale of stock, number of shares authorized (in shares) | shares		579,873		579,873
Expected proceeds from sale of stock				$ 394.8
Expected issuance of common stock, weighted average price (in dollars per share) | $ / shares		$ 680.77		$ 680.77
2020 ATM Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Sale of stock, equity offering agreement, available for sale		$ 605.2		$ 605.2
Issuance of common stock in offering (in shares) | shares		0	137,604	0	137,604
Gross proceeds from sale of stock			$ 99.6		$ 99.6