Computation of Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Numerator:
Net income used for calculating basic and diluted income per share	$ 415,049	$ 229,548	$ 210,545	$ 180,009	$ 198,043	$ 295,783	$ 855,142	$ 673,835
Denominator:
Weighted average number of common shares used in the calculation of basic income per share (in shares)	77,484			78,923			77,880	79,220
Dilutive effect of outstanding awards associated with stock-based compensation plans (in shares)	484			597			564	642
Shares used in the calculation of diluted income per share (in shares)	77,968			79,520			78,444	79,862
Basic income per share (in dollars per share)	$ 5.36			$ 2.28			$ 10.98	$ 8.51
Diluted income per share (in dollars per share)	$ 5.32			$ 2.26			$ 10.90	$ 8.44
Antidilutive securities excluded from computation of (loss) income per share (in shares)	0			100			100	100