Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement of Comprehensive Income [Abstract]
Net earnings	$ 108,755	$ 116,439	$ 202,322	$ 213,486
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net of tax of $5,016 and $5,612 for the three months ended June 30, 2017 and 2016 and $9,892 and $424 for the six months ended June 30, 2017 and 2016	9,236	(10,297)	18,096	(717)
Other comprehensive income (loss)	9,236	(10,297)	18,096	(717)
Comprehensive income	117,991	106,142	220,418	212,769
Less comprehensive (loss) income attributable to the noncontrolling interest	(31)	330	218	907
Comprehensive income attributable to shareholders	$ 118,022	$ 105,812	$ 220,200	$ 211,862