Accrued Liabilities (Summary of Accrued Liabilities) (Details) (USD $) In Thousands, unless otherwise specified	Jan. 27, 2013	Jan. 29, 2012
Payables and Accruals [Abstract]
Compensation	$ 23,140	$ 14,330
Equity awards accounted for as a liability	3,241	3,988
Deferred compensation	1,410	901
Accrued sales and marketing expenses	3,202	1,742
Accrued professional fees	3,835	1,949
Accrued interest expense	1,177	0
Income taxes payable	4,113	4,260
Accrued taxes	266	437
Other	8,892	4,782
Total accrued liabilities, current	$ 49,276	$ 32,389