Stockholders' Equity (Employee Stock Purchase Plan) (Details) - USD ($) $ / shares in Units, shares in Millions	12 Months Ended
	Jan. 28, 2017	Jan. 30, 2016	Jan. 31, 2015
Stockholders' Equity Note [Abstract]
Plan participant's annual percentage ceiling for ESPP (in percentage)	10.00%
Plan participant's annual dollar amount ceiling for ESPP	$ 25,000
Purchase price for shares under ESPP (in percentage)	85.00%
Discount rate under the ESPP (in percentage)	15.00%
Shares purchased by employees (in shares)	0.3	0.4	0.4
Shares purchased by employees, average price per share (in dollars per share)	$ 51.86	$ 43.16	$ 32.18
Shares issued under plan during period (in shares)	39.4
Shares remaining for future issuance (in shares)	5.6