Earnings Per Share (Tables)

6 Months Ended

Jul. 31, 2011

Earnings Per Share [Abstract]

Reconciliation of numerators and denominators for basic and diluted EPS computations

	Three Months Ended July 31,				Six Months Ended July 31,
(in thousands)	2011		2010		2011		2010
Net earnings for basic and diluted EPS	$	90,043	$	67,675	$	171,106	$	132,100
Weighted-average shares for basic EPS		128,030		126,897		127,816		126,798
Incremental shares based upon the assumed exercise of stock options and unvested restricted stock units		1,764		1,488		1,771		1,666
Weighted-average shares for diluted EPS		129,794		128,385		129,587		128,464