Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net earnings	$ 191,719	$ 160,627	$ 498,689	$ 454,268
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net of tax expense (benefit) of $4,200 and $(5,803) for the three months ended September 30, 2020 and 2019 and $226 and $(5,364) for the nine months ended September 30, 2020 and 2019	17,429	(14,603)	(5,010)	(14,007)
Reclassification adjustments for foreign currency realized losses, net of tax of $145 for the nine months ended September 30, 2019	0	0	0	535
Other comprehensive income (loss)	17,429	(14,603)	(5,010)	(13,472)
Comprehensive income	209,148	146,024	493,679	440,796
Less comprehensive (loss) income attributable to the noncontrolling interest	(36)	481	253	1,020
Comprehensive income attributable to shareholders	$ 209,184	$ 145,543	$ 493,426	$ 439,776