Condensed Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Net income	$ 67,437	$ 85,928
Other comprehensive income (loss):
Foreign currency translation adjustments, before tax	2,469	(4,317)
Income tax benefit	22	30
Foreign currency translation adjustments, net of tax	2,491	(4,287)
Changes in employee benefit related items:
Amortization of prior service cost	3	2
Recognized actuarial gain	143	84
Changes in employee benefit related items	146	86
Income tax (expense)	(1)	(3)
Employee benefit related items, net of tax	145	83
Other comprehensive income (loss)	2,636	(4,204)
Comprehensive income	$ 70,073	$ 81,724