Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Statement of Comprehensive Income [Abstract]
Net earnings	$ 140,111	$ 136,200
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net of tax of $521 and $5,512 for the three months ended March 31, 2019 and 2018	1,365	8,851
Other comprehensive income	1,365	8,851
Comprehensive income	141,476	145,051
Less comprehensive income attributable to the noncontrolling interest	282	387
Comprehensive income attributable to shareholders	$ 141,194	$ 144,664