Other Comprehensive Income (Details) (USD $) In Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Jun. 30, 2011	Jun. 30, 2010
Other Comprehensive Income [Abstract]
Net earnings	$ 81,425	$ 53,605	$ 149,843	$ 106,318
Foreign currency translation adjustment, net of taxes	1,914	(4,779)	9,778	(6,534)
Net derivative gain (loss), net of taxes	(1,100)	85	(1,460)	(793)
Amount of loss reclassified from accumulated OCI into income, net of taxes	451	1,736	1,113	3,687
Total comprehensive income	$ 82,690	$ 50,647	$ 159,274	$ 102,678