Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Comprehensive Income (Loss), Net of Tax, Attributable to Parent [Abstract]
Net earnings	$ 39,910	$ 31,224	$ 136,033	$ 115,342
Foreign currency translation adjustments	3,470	(3,647)	3,439	(2,854)
Total other comprehensive income (loss)	3,470	(3,647)	3,439	(2,854)
COMPREHENSIVE INCOME	$ 43,380	$ 27,577	$ 139,472	$ 112,488