Stock-Based Compensation (Unvested Restricted Stock Activity) (Details) - Restricted stock shares in Thousands	9 Months Ended
	Oct. 28, 2017 $ / shares shares
Number of shares
Beginning Balance (in shares) | shares	5,563
Awarded (in shares) | shares	1,266
Released (in shares) | shares	(1,583)
Forfeited (in shares) | shares	(37)
Ending Balance (in shares) | shares	5,209
Weighted average grant date fair value
Beginning Balance (in dollars per share) | $ / shares	$ 43.19
Awarded (in dollars per share) | $ / shares	64.83
Released (in dollars per share) | $ / shares	37.97
Forfeited (in dollars per share) | $ / shares	49.03
Ending Balance (in dollars per share) | $ / shares	$ 50.77