Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net earnings	$ 698,214	$ 592,016	$ 619,790
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net of tax expense (benefit) of $4,254 in 2020, $25,731 in 2019 and $(13,364) in 2018	30,759	(26,553)	(32,390)
Reclassification adjustment for foreign currency realized losses, net of tax of $145 in 2019	0	535	0
Other comprehensive income (loss)	30,759	(26,018)	(32,390)
Comprehensive income	728,973	565,998	587,400
Less comprehensive income attributable to the noncontrolling interest	1,399	1,309	718
Comprehensive income attributable to shareholders	$ 727,574	$ 564,689	$ 586,682