Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net earnings	$ 27,132	$ 32,154	$ 116,457	$ 116,636
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(8,903)	657	(7,278)	(9,774)
Total comprehensive income	$ 18,229	$ 32,811	$ 109,179	$ 106,862