Note 5 - Share-based Compensation (Tables)

12 Months Ended

Dec. 31, 2024

Notes Tables

Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Years ended December 31,
	2024		2023		2022
Restricted share units
Pretax compensation expense	$	49,172	$	56,837	$	54,276
Tax benefit		12,214		12,561		13,216
Restricted share units, net of tax	$	36,958	$	44,276	$	41,060
Performance share units
Pretax compensation expense	$	16,514	$	22,352	$	23,259
Tax benefit		4,102		4,940		5,664
Performance share awards, net of tax	$	12,412	$	17,412	$	17,595

Schedule of Nonvested Restricted Stock Units Activity [Table Text Block]

Restricted Share Units	Number of Shares			Weighted Average Grant Date Fair Value
Unvested at December 31, 2023		936,492		$	147.02
Granted		269,322			192.98
Vested		(430,890	)		146.06
Forfeited		(37,687	)		171.81
Unvested at December 31, 2024		737,237		$	163.83

Schedule of Nonvested Performance-Based Units Activity [Table Text Block]

Performance Share Units	Number of Shares			Weighted Average Grant Date Fair Value
Unvested at December 31, 2023		386,723		$	163.87
Granted		140,469			195.24
Vested		(138,115	)		150.73
Forfeited		(36,786	)		186.85
Unvested at December 31, 2024		352,291		$	179.14