Note 4 - Stock-based Compensation - Summary of Stock Option Activity (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Outstanding, Options (in shares)	2,072
Outstanding, weighted average exercise price (in dollars per share)	$ 180.56
Outstanding, Weighted-Average Remaining Contractual Term (Year)	6 years 3 months 18 days	5 years 10 months 24 days
Outstanding, Aggregate Intrinsic Value	$ 123	$ 135
Granted, Options (in shares)	305
Granted, weighted average exercise price (in dollars per share)	$ 248.82
Exercised, Options (in shares)	(102)
Exercised, weighted average exercise price (in dollars per share)	$ 127.77
Forfeited or expired, Options (in shares)	(5)
Forfeited or expired, weighted average exercise price (in dollars per share)	$ 223.49
Outstanding, Options (in shares)	2,270	2,072
Outstanding, weighted average exercise price (in dollars per share)	$ 192.01	$ 180.56
Vested or expected to vest, Options (in shares)	2,251
Vested or expected to vest, weighted average exercise price (in dollars per share)	$ 191.67
Vested or expected to vest, Weighted-Average Remaining Contractual Term (Year)	6 years 3 months 18 days
Vested or expected to vest, Aggregate Intrinsic Value	$ 123
Exercisable, Options (in shares)	1,642
Options, exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 176.86
Options, Exercisable, Weighted-Average Remaining Contractual Term (Year)	5 years 3 months 18 days
Options, Exercisable, Aggregate Intrinsic Value	$ 113