Note 4 - Stock-based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	6 Months Ended	12 Months Ended
	Jun. 30, 2022	Dec. 31, 2021
Outstanding, Options (in shares)	2,106
Outstanding, weighted average exercise price (in dollars per share)	$ 149.84
Outstanding, Weighted-Average Remaining Contractual Term (Year)	6 years 6 months	6 years 3 months 18 days
Outstanding, Aggregate Intrinsic Value	$ 104	$ 215
Granted, Options (in shares)	328
Granted, weighted average exercise price (in dollars per share)	$ 244.35
Exercised, Options (in shares)	(339)
Exercised, weighted average exercise price (in dollars per share)	$ 127.62
Forfeited or expired, Options (in shares)	(25)
Forfeited or expired, weighted average exercise price (in dollars per share)	$ 211.39
Outstanding, Options (in shares)	2,070	2,106
Outstanding, weighted average exercise price (in dollars per share)	$ 167.71	$ 149.84
Vested or expected to vest, Options (in shares)	2,049
Vested or expected to vest, weighted average exercise price (in dollars per share)	$ 167.17
Vested or expected to vest, Weighted-Average Remaining Contractual Term (Year)	6 years 4 months 24 days
Vested or expected to vest, Aggregate Intrinsic Value	$ 104
Exercisable, Options (in shares)	1,390
Options, exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 142.20
Options, Exercisable, Weighted-Average Remaining Contractual Term (Year)	5 years 3 months 18 days
Options, Exercisable, Aggregate Intrinsic Value	$ 99