Stock-Based Compensation (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Jan. 31, 2012 Y
Activity of stock options
Options, Outstanding as of January 31, 2011	4,126,678
Weighted Average Exercise Price, Outstanding as of January 31, 2011	$ 36.76
Options, Granted	473,519
Weighted Average Exercise Price, Granted	$ 17.72
Options, Exercised	(15,807)
Weighted Average Exercise Price, Exercised	$ 12.22
Options, Forfeited/Expired	(162,147)
Weighted Average Exercise Price, Forfeited/Expired	$ 44.54
Options, Outstanding as of January 31, 2012	4,422,243
Weighted Average Exercise Price, Outstanding as of January 31, 2012	$ 34.53
Weighted Average Remaining Contractual Term, Outstanding as of January 31, 2012	5.10
Intrinsic Value, Outstanding as of January 31, 2012	$ 1,480
Options, Exercisable (fully vested) at January 31, 2012	3,189,378
Weighted Average Exercise Price, Exercisable as of January 31, 2012	$ 40.79
Weighted Average Remaining Contractual Term, Exercisable	3.91
Intrinsic Value, as of January 31, 2012	$ 520