Condensed Consolidated Statements of Comprehensive Income (unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Condensed Consolidated Statements of Comprehensive Income (unaudited) [Abstract]
Net earnings	$ 136,323	$ 116,708	$ 372,590	$ 339,830
Comprehensive income, net of tax
Foreign currency translation adjustments	31,902	36,395	(10,219)	22,348
Total other comprehensive income/(loss), net of tax	31,902	36,395	(10,219)	22,348
Comprehensive income	$ 168,225	$ 153,103	$ 362,371	$ 362,178