CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss	Retained Earnings
Balance at Beginning of Year (in shares) at Jan. 28, 2017		236,100,000
Balance at Beginning of Year at Jan. 28, 2017	$ 5,389.5	$ 2.4	$ 2,472.1	$ (37.6)	$ 2,952.6
Statement of Stockholders' Equity [Roll Forward]
Net income (loss)	1,714.3				1,714.3
Total other comprehensive income (loss)	5.3			5.3
Issuance of stock under Employee Stock Purchase Plan (in shares)		200,000
Issuance of stock under Employee Stock Purchase Plan	8.4		8.4
Exercise of stock options (in shares)		500,000
Exercise of stock options	26.6		26.6
Stock-based compensation, net (in shares)		500,000
Stock-based compensation, net	38.2		38.2
Balance at End of Year (in shares) at Feb. 03, 2018		237,300,000
Balance at End of Year at Feb. 03, 2018	7,182.3	$ 2.4	2,545.3	(32.3)	4,666.9
Statement of Stockholders' Equity [Roll Forward]
Net income (loss)	(1,590.8)				(1,590.8)
Total other comprehensive income (loss)	(6.0)			(6.0)
Issuance of stock under Employee Stock Purchase Plan (in shares)		200,000
Issuance of stock under Employee Stock Purchase Plan	10.0		10.0
Exercise of stock options (in shares)		100,000
Exercise of stock options	7.5		7.5
Stock-based compensation, net (in shares)		500,000
Stock-based compensation, net	39.9		39.9
Balance at End of Year (in shares) at Feb. 02, 2019		238,100,000
Balance at End of Year at Feb. 02, 2019	5,642.9	$ 2.4	2,602.7	(38.3)	3,076.1
Statement of Stockholders' Equity [Roll Forward]
Net income (loss)	827.0				827.0
Total other comprehensive income (loss)	(1.5)			(1.5)
Issuance of stock under Employee Stock Purchase Plan (in shares)		100,000
Issuance of stock under Employee Stock Purchase Plan	$ 9.4		9.4
Exercise of stock options (in shares)	73,383
Exercise of stock options	$ 5.8		5.8
Stock-based compensation, net (in shares)		400,000
Stock-based compensation, net	36.5		36.5
Repurchase of stock (in shares)		(1,900,000)
Repurchase of stock	(200.0)		(200.0)
Balance at End of Year (in shares) at Feb. 01, 2020		236,700,000
Balance at End of Year at Feb. 01, 2020	$ 6,254.8	$ 2.4	$ 2,454.4	$ (39.8)	$ 3,837.8