Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net earnings	$ 153,530	$ 140,946	$ 293,641	$ 277,146
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net of tax of $82 and $15,171 for the three months ended June 30, 2019 and 2018 and $439 and $9,660 for the six months ended June 30, 2019 and 2018	(769)	(26,051)	596	(17,200)
Reclassification adjustments for foreign currency realized losses, net of tax of $145 for the three and six months ended June 30, 2019	535	0	535	0
Other comprehensive income (loss)	(234)	(26,051)	1,131	(17,200)
Comprehensive income	153,296	114,895	294,772	259,946
Less comprehensive income attributable to the noncontrolling interest	257	10	539	397
Comprehensive income attributable to shareholders	$ 153,039	$ 114,885	$ 294,233	$ 259,549