Accelerated Share Repurchase Agreements (Narrative) (Details) - USD ($) shares in Millions, $ in Millions	1 Months Ended						3 Months Ended							6 Months Ended			12 Months Ended
	Jan. 31, 2016	Jan. 05, 2016	May 03, 2015	Apr. 15, 2015	May 04, 2014	Apr. 10, 2014	Jan. 31, 2016	Nov. 01, 2015	Aug. 02, 2015	May 03, 2015	Nov. 02, 2014	Aug. 03, 2014	May 04, 2014	Jan. 31, 2016	Nov. 01, 2015	Nov. 02, 2014	Jan. 29, 2017	Jan. 31, 2016	Feb. 01, 2015
Accelerated Share Repurchases [Line Items]
Cash paid for repurchase of common stock																	$ 6,880	$ 7,000	$ 7,000
Treasury Stock, Value	$ 33,194						$ 33,194							$ 33,194			$ 40,194	$ 33,194
Q1 Accelerated Share Repurchase Agreement [Member]
Accelerated Share Repurchases [Line Items]
Cash paid for repurchase of common stock										$ 850			$ 950
Number of shares of common stock repurchased pursuant to accelerated share repurchase agreement			0.5	7.0	2.6	9.5				7.5			12.1
Q2 Accelerated Share Repurchase Agreement [Member]
Accelerated Share Repurchases [Line Items]
Cash paid for repurchase of common stock									$ 1,500			$ 1,750
Number of shares of common stock repurchased pursuant to accelerated share repurchase agreement								1.3	12.0		4.5	16.9			13.3	21.4
Q3 Accelerated Share Repurchase Agreement [Member]
Accelerated Share Repurchases [Line Items]
Cash paid for repurchase of common stock								$ 1,375
Number of shares of common stock repurchased pursuant to accelerated share repurchase agreement							1.3	10.1						11.4
Q4 Accelerated Share Repurchase Agreement [Member]
Accelerated Share Repurchases [Line Items]
Cash paid for repurchase of common stock							$ 1,500
Number of shares of common stock repurchased pursuant to accelerated share repurchase agreement	1.7	9.7					11.4