Note 3 - Stock-based Compensation - RSU Summary (Details) shares in Thousands	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Balance (in shares) | shares	2,659
Weighted-Average Grant Date Fair Value Per Share, ending balance (in dollars per share) | $ / shares	$ 176.5
Granted (in shares) | shares	302
Weighted-Average Grant Date Fair Value Per Share, granted (in dollars per share) | $ / shares	$ 445.5
Vested (in shares) | shares	(786)
Weighted-Average Grant Date Fair Value Per Share, vested (in dollars per share) | $ / shares	$ 187.56
Forfeited (in shares) | shares	(23)
Weighted-Average Grant Date Fair Value Per Share, forfeited (in dollars per share) | $ / shares	$ 192.23
Balance (in shares) | shares	2,152
Weighted-Average Grant Date Fair Value Per Share, ending balance (in dollars per share) | $ / shares	$ 209.67
Time-Based RSUs [Member]
Balance (in shares) | shares	106
Weighted-Average Grant Date Fair Value Per Share, ending balance (in dollars per share) | $ / shares	$ 327.13
Granted (in shares) | shares	45
Weighted-Average Grant Date Fair Value Per Share, granted (in dollars per share) | $ / shares	$ 479.76
Vested (in shares) | shares	(42)
Weighted-Average Grant Date Fair Value Per Share, vested (in dollars per share) | $ / shares	$ 288.51
Forfeited (in shares) | shares	(5)
Weighted-Average Grant Date Fair Value Per Share, forfeited (in dollars per share) | $ / shares	$ 376.82
Balance (in shares) | shares	104
Weighted-Average Grant Date Fair Value Per Share, ending balance (in dollars per share) | $ / shares	$ 406.52
PSUs and MPSUs [Member]
Balance (in shares) | shares	748
Weighted-Average Grant Date Fair Value Per Share, ending balance (in dollars per share) | $ / shares	$ 275.7
Granted (in shares) | shares	226	[1]
Weighted-Average Grant Date Fair Value Per Share, granted (in dollars per share) | $ / shares	$ 449.34
Vested (in shares) | shares	(504)
Weighted-Average Grant Date Fair Value Per Share, vested (in dollars per share) | $ / shares	$ 257.41
Forfeited (in shares) | shares	(4)
Weighted-Average Grant Date Fair Value Per Share, forfeited (in dollars per share) | $ / shares	$ 312.12
Balance (in shares) | shares	466
Weighted-Average Grant Date Fair Value Per Share, ending balance (in dollars per share) | $ / shares	$ 380.12
MSUs [Member]
Balance (in shares) | shares	1,805
Weighted-Average Grant Date Fair Value Per Share, ending balance (in dollars per share) | $ / shares	$ 126.57
Granted (in shares) | shares	31
Weighted-Average Grant Date Fair Value Per Share, granted (in dollars per share) | $ / shares	$ 330.95
Vested (in shares) | shares	(240)
Weighted-Average Grant Date Fair Value Per Share, vested (in dollars per share) | $ / shares	$ 23.57
Forfeited (in shares) | shares	(14)
Weighted-Average Grant Date Fair Value Per Share, forfeited (in dollars per share) | $ / shares	$ 104.16
Balance (in shares) | shares	1,582
Weighted-Average Grant Date Fair Value Per Share, ending balance (in dollars per share) | $ / shares	$ 146.51

[1] Amount reflects the number of awards that may ultimately be earned based on management's probability assessment of the achievement of performance conditions at each reporting period.