Derivatives and Foreign Exchange Risk Management (Effect on Income Statement) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended			3 Months Ended		9 Months Ended		1 Months Ended			3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended	9 Months Ended		1 Months Ended
	Jan. 27, 2012	Jan. 28, 2011	Jan. 27, 2012	Jan. 28, 2011	Apr. 29, 2011	Jan. 27, 2012 Foreign Exchange Contract	Jan. 28, 2011 Foreign Exchange Contract	Jan. 27, 2012 Foreign Exchange Contract	Jan. 28, 2011 Foreign Exchange Contract	Jul. 31, 2011 Terminated Interest Rate Swap	Aug. 31, 2011 Terminated Interest Rate Swap 2	Oct. 28, 2011 Forward Starting Interest Rate Swap	Jan. 27, 2012 Other Expense Foreign Exchange Contract	Jan. 28, 2011 Other Expense Foreign Exchange Contract	Jan. 27, 2012 Other Expense Foreign Exchange Contract	Jan. 28, 2011 Other Expense Foreign Exchange Contract	Jan. 27, 2012 Cost of Products Sold	Jan. 28, 2011 Cost of Products Sold Foreign Exchange Contract	Jan. 27, 2012 Cost of Products Sold Foreign Exchange Contract	Jan. 28, 2011 Cost of Products Sold Foreign Exchange Contract	Jan. 28, 2011 Other Income Foreign Exchange Contract	Jan. 28, 2011 Other Income Foreign Exchange Contract	Jan. 27, 2012 Fair Value Hedging Interest Rate Swap	Jul. 31, 2011 Fair Value Hedging Terminated Interest Rate Swap	Aug. 31, 2011 Fair Value Hedging Terminated Interest Rate Swap 2
Foreign Currency Derivative Instruments Not Designated as Hedging Instruments
Notional amount of foreign currency derivative instruments not designated as hedging instruments	$ 2,049		$ 2,049		$ 2,453
Gain (loss) on foreign currency derivative instruments not designated as hedging instruments													46	(12)	66	(33)
Summary of Cash Flow Hedge Activity
Notional amount of cash flow hedge instruments	2,955		2,955		4,381
Derivative instruments, gain (loss) recognized in other comprehensive income (loss), effective portion, net	201	9	332	(327)		201	9	332	(327)
Derivative instruments, gain (loss) reclassified from accumulated OCI into income, effective portion, net	(25)	14	(119)	89									(24)		(133)		(1)	13	14	18	1	71
Summary of Fair Value Hedge Activity
Derivative, cash received on hedge										46	42
Derivative interest accrued on hedge										10	7
Unrealized gain (loss) on fair value hedging instruments	164		164
Unrealized gain (loss) on hedged item in fair value hedge	(164)		(164)
Gain (loss) on fair value hedge ineffectiveness, net			1	2
Interest Rate Derivatives
Notional amount of iInterest rate cash flow hedge derivatives	1,950		1,950		3,500					900	650	750
Description of derivative hedged item																							fixed rate obligations including the Company’s $1.250 billion 3.000 percent 2010 Senior Notes due 2015, $600 million 4.750 percent 2005 Senior Notes due 2015, $500 million 2.625 percent 2011 Senior Notes due 2016, and the $500 million 4.125 percent 2011 Senior Notes due 2021.	the fixed interest rate obligation under the Company’s $2.200 billion 1.625 percent 2013 Senior Convertible Notes and $550 million 4.500 percent Senior Notes due 2014.	of the fixed interest rate obligation under the Company’s $1.250 billion 3.000 percent 2010 Senior Notes due 2015.
Derivative, average fixed interest rate												2.84%
Unrealized gain (loss) on interest rate cash flow hedges	(43)		(43)
Unrealized gain (loss) on interest rate cash flow hedges, net, AOCI					$ 257