Condensed Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Condensed Consolidated Statements of Comprehensive Income (unaudited) [Abstract]
Net earnings	$ 158,071	$ 151,416
Other comprehensive income, net of tax:
Foreign currency translation adjustments	30,412	1,743
Total other comprehensive income, net of tax	30,412	1,743
Comprehensive income	$ 188,483	$ 153,159