Condensed Consolidated Statements of Comprehensive Income (unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Condensed Consolidated Statements of Comprehensive Income (unaudited) [Abstract]
Net earnings	$ 111,353	$ 114,813	$ 236,267	$ 223,122
Comprehensive income, net of tax
Foreign currency translation adjustments	(3,632)	(33,208)	(42,121)	(14,047)
Total other comprehensive income, net of tax	(3,632)	(33,208)	(42,121)	(14,047)
Comprehensive income	$ 107,721	$ 81,605	$ 194,146	$ 209,075