Postretirement Benefits (Components Of SERP Expense Recognized In The Consolidated Statements Of Earnings) (Details) - Components of SERP expense [Member] - USD ($) $ in Millions	12 Months Ended
	Jan. 28, 2017	Jan. 30, 2016	Jan. 31, 2015
Postretirement Benefits Disclosure [Line Items]
Participant service cost	$ 3	$ 3	$ 3
Interest cost	7	7	7
Amortization of net loss and other	3	11	6
Total SERP expense	$ 13	$ 21	$ 16