Employee Stock and Savings Plans and Stockholders Equity Summary Stock Option Activity (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Jan. 31, 2014	Jan. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Stock options outstanding	3,587	6,717
Stock options granted	0
Stock options exercised	(3,124)
Stock options forfeited	3
Stock options expired	(9)
Stock options outstanding exercisable	2,933
Stock options vested and expected to vest	3,587
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures [Abstract]
Weighted average exercise price of stock options outstanding	$ 9.87	$ 11.08
Weighted average exercise price of stock options granted	$ 0.00
Weighted average exercise price of stock options exercised	$ 12.43
Weighted average exercise price of stock options forfeited	$ 4.20
Weighted average exercise price of stock options expired	$ 12.37
Weighted average exercise price of stock options exercisable	$ 8.94
Weighted average exercise price of stock options vested and expected to vest	$ 9.87
Share Based Compensation Arrangement By Share Based Payment Award Options Weighted Average Remaining Contractual Term [Abstract]
Weighted average remaining contractual term of stock options outstanding	5 years 4 months 17 days
Weighted average remaining contractual term of stock options exercisable	4 years 9 months 14 days
Weighted average remaining contractual term of stock options vested and expected to vest	5 years 4 months 17 days
Share Based Compensation Arrangement By Share Based Payment Award Options Aggregate Intrinsic Value [Abstract]
Aggregate intrinsic value of stock options outstanding	$ 39,195
Aggregate intrinsic value of options exercisable	34,784
Aggregate intrinsic value of stock options vested and expected to vest	$ 39,195

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