Common Shares, Treasury Shares, Reserves and Dividends - Share Repurchase (Details) - USD ($)	12 Months Ended
	Jan. 28, 2017	Jan. 30, 2016	Jan. 31, 2015	Aug. 31, 2016	Feb. 29, 2016
Class of Stock [Line Items]
Shares repurchased (shares)	11,200,000	1,000,000	300,000
Amount repurchased	$ 1,000,000,000	$ 130,000,000	$ 29,800,000
Average repurchase price per share (usd per share)	$ 89.10	$ 127.63	$ 103.37
2016 Program
Class of Stock [Line Items]
Amount authorized	$ 1,375,000,000			$ 625,000,000	$ 750,000,000
Shares repurchased (shares)	10,004,333
Amount repurchased	$ 864,400,000
Average repurchase price per share (usd per share)	$ 86.40
2013 Program
Class of Stock [Line Items]
Amount authorized	$ 350,000,000.0
Shares repurchased (shares)	1,218,621	1,018,568	288,393
Amount repurchased	$ 135,600,000	$ 130,000,000	$ 29,800,000
Average repurchase price per share (usd per share)	$ 111.26	$ 127.63	$ 103.37
Remaining authorized repurchase amount	$ 510,600,000