Financial Instruments, Risk Management Activities, and Fair Values (Schedule of gains and losses on hedges) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	May 26, 2013	May 27, 2012
Cash Flow Hedging [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in other comprehensive income (OCI)	$ 35.5	$ (85.9)
Amount of gain (loss) reclassified from AOCI into earnings	(17.3)	(18.1)
Amount of gain (loss) recognized in earnings	0.4	(0.8)
Fair Value Hedging [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in earnings	0.8	(0.8)
Not Designated as Hedging [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in earnings	16.0	(124.8)
Interest Rate Contract [Member] | Cash Flow Hedging [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in other comprehensive income (OCI)	19.1	(78.6)
Amount of gain (loss) reclassified from AOCI into earnings	(12.5)	(8.2)
Amount of gain (loss) recognized in earnings	0	(0.5)
Interest Rate Contract [Member] | Fair Value Hedging [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in earnings	0.8	(0.8)
Interest Rate Contract [Member] | Not Designated as Hedging [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in earnings	0	0
Foreign Exchange Contract [Member] | Cash Flow Hedging [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in other comprehensive income (OCI)	16.4	(7.3)
Amount of gain (loss) reclassified from AOCI into earnings	(4.8)	(9.9)
Amount of gain (loss) recognized in earnings	0.4	(0.3)
Foreign Exchange Contract [Member] | Fair Value Hedging [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in earnings	0	0
Foreign Exchange Contract [Member] | Not Designated as Hedging [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in earnings	11.6	(1.3)
Equity Contract [Member] | Cash Flow Hedging [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in other comprehensive income (OCI)	0	0
Amount of gain (loss) reclassified from AOCI into earnings	0	0
Amount of gain (loss) recognized in earnings	0	0
Equity Contract [Member] | Fair Value Hedging [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in earnings	0	0
Equity Contract [Member] | Not Designated as Hedging [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in earnings	12.0	(1.0)
Commodity Contract [Member] | Cash Flow Hedging [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in other comprehensive income (OCI)	0	0
Amount of gain (loss) reclassified from AOCI into earnings	0	0
Amount of gain (loss) recognized in earnings	0	0
Commodity Contract [Member] | Fair Value Hedging [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in earnings	0	0
Commodity Contract [Member] | Not Designated as Hedging [Member]
Derivative Instruments Gain Loss [Line Items]
Amount of gain (loss) recognized in earnings	$ (7.6)	$ (122.5)