Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net earnings	$ 107,949	$ 118,736	$ 321,435	$ 344,397
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net of tax of $202 and $11,669 for the three months ended September 30, 2016 and 2015 and $223 and $19,866 for the nine months ended September 30, 2016 and 2015	260	(21,692)	(457)	(37,081)
Other comprehensive income (loss)	260	(21,692)	(457)	(37,081)
Comprehensive income	108,209	97,044	320,978	307,316
Less comprehensive income attributable to the noncontrolling interest	260	35	1,167	804
Comprehensive income attributable to shareholders	$ 107,949	$ 97,009	$ 319,811	$ 306,512