Equity Awards - Summary of Stock Option Activity (Detail) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2021
Number of Shares
Outstanding, beginning balance (in shares)	454,000	522,000	522,000
Granted (in shares)	54,000	36,000
Exercised (in shares)	(24,000)	(104,000)
Outstanding, ending balance (in shares)	484,000	454,000	484,000
Vested and expected to vest (in shares)	449,000		449,000
Vested and exercisable (in shares)	285,000		285,000
Weighted- Average Exercise Price Per Share
Outstanding, beginning balance (in dollars per share)	$ 149.23	$ 107.14	$ 107.14
Granted (in dollars per share)	77.96	587.91
Exercised (in dollars per share)	16.46	88.28
Outstanding, ending balance (in dollars per share)	147.70	$ 149.23	147.70
Vested and expected to vest (in dollars per share)	139.55		139.55
Vested and exercisable (in dollars per share)	$ 60.12		$ 60.12
Weighted-average remaining contractual term, outstanding			4 years 9 months 18 days
Weighted-average remaining contractual term, vested and expected to vest			4 years 7 months 6 days
Weighted-average remaining contractual term, vested and exercisable			2 years 10 months 24 days
Aggregate intrinsic value, exercised	$ 11	$ 47
Aggregate intrinsic value, outstanding	171		$ 171
Aggregate intrinsic value, vested and expected to vest	166		166
Aggregate intrinsic value, vested and exercisable	$ 140		$ 140

The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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- Definition

The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.