Stockholders' Equity - Narrative (Detail) - USD ($)	1 Months Ended	3 Months Ended
	May 31, 2020	Mar. 31, 2021	Mar. 31, 2020	Oct. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock in public offering of common stock (in shares)	2,587,500
Issuance of common stock in public offering of common stock	$ 1,700,000,000
Restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units, approved (in shares)		646,388
Weighted-average grant date fair value (in dollars per share)		$ 650.40
Service period (in years)		3 years 6 months 7 days
2020 ATM Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock in public offering of common stock (in shares)		0
Sale of stock, equity offering agreement, authorized				$ 1,500,000,000
Legacy ATM Program
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock in public offering of common stock (in shares)			162,530
Issuance of common stock in public offering of common stock			$ 101,800,000