Condensed Consolidated Statements of Comprehensive Income (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Statement of Comprehensive Income [Abstract]
Net earnings	$ 190,273	$ 167,079	$ 527,900	$ 476,564
Other comprehensive income/(loss), net of tax:
Foreign currency translation adjustments	67,535	9,054	147,462	(35,673)
Total other comprehensive income/(loss), net of tax	67,535	9,054	147,462	(35,673)
Comprehensive income	$ 257,808	$ 176,133	$ 675,362	$ 440,891