Financial Instruments, Risk Management Activities, and Fair Values (Schedule of fair value measurement inputs) (Details) - USD ($) $ in Millions		12 Months Ended
		May 29, 2016		May 31, 2015		May 25, 2014	May 26, 2013
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		$ 40.7		$ 40.0
Other Assets, Fair Value Disclosure		200.2		203.0
Total Assets, Fair Value Disclosure		239.4		246.3
Derivative Liability, Fair Value		(38.9)		(124.7)
Other Liabilities, Fair Value Disclosure		0.0		0.0
Total Liabilities, Fair Value Disclosure		(44.4)		(132.5)
Book value of long-lived assets		3,743.6		3,783.3
Proceeds from sale of long-lived assets		4.4		11.0		$ 6.6
Non-cash impairment charge of indefinite-lived intangible assets		0.0		260.0
Book value of indefinite-lived intangible assets		4,538.6		4,677.0		$ 5,014.3	$ 5,015.1
Long-Lived Assets [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure		26.0	[1]	37.8	[2]
Other Liabilities, Fair Value Disclosure		0.0	[1]	0.0	[2]
Non-cash impairment charge of long-lived assets		11.4		30.3
Book value of long-lived assets		28.2		68.1
Indefinite-lived Intangible Asset [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	[3]			154.3
Other Liabilities, Fair Value Disclosure	[3]			0.0
Green Giant [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Non-cash impairment charge of indefinite-lived intangible assets				260.0
Green Giant [Member] | Indefinite-lived Intangible Asset [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure				154.3
Non-cash impairment charge of long-lived assets				260.0
Book value of indefinite-lived intangible assets				414.3
Designated as Hedging Instrument [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		19.9		29.5
Derivative Liability, Fair Value		(15.2)		(23.3)
Not Designated as Hedging [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		19.3		13.8
Derivative Liability, Fair Value		(29.2)		(109.2)
Level 1 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure		8.4		8.3
Total Assets, Fair Value Disclosure		11.0		15.5
Other Liabilities, Fair Value Disclosure		0.0		0.0
Total Liabilities, Fair Value Disclosure		(0.6)		0.0
Level 1 [Member] | Long-Lived Assets [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure		0.0	[1]	0.0	[2]
Other Liabilities, Fair Value Disclosure		0.0	[1]	0.0	[2]
Level 1 [Member] | Indefinite-lived Intangible Asset [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	[3]			0.0
Other Liabilities, Fair Value Disclosure	[3]			0.0
Level 1 [Member] | Designated as Hedging Instrument [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		0.0		0.0
Derivative Liability, Fair Value		0.0		0.0
Level 1 [Member] | Not Designated as Hedging [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		2.6		7.2
Derivative Liability, Fair Value		(0.6)		0.0
Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure		191.8		40.4
Total Assets, Fair Value Disclosure		228.4		76.5
Other Liabilities, Fair Value Disclosure		0.0		0.0
Total Liabilities, Fair Value Disclosure		(43.8)		(132.5)
Level 2 [Member] | Long-Lived Assets [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure		26.0	[1]	37.8	[2]
Other Liabilities, Fair Value Disclosure		0.0	[1]	0.0	[2]
Level 2 [Member] | Indefinite-lived Intangible Asset [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	[3]			0.0
Other Liabilities, Fair Value Disclosure	[3]			0.0
Level 2 [Member] | Designated as Hedging Instrument [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		19.9		29.5
Derivative Liability, Fair Value		(15.2)		(23.3)
Level 2 [Member] | Not Designated as Hedging [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		16.7		6.6
Derivative Liability, Fair Value		(28.6)		(109.2)
Level 3 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure		0.0		154.3
Total Assets, Fair Value Disclosure		0.0		154.3
Other Liabilities, Fair Value Disclosure		0.0		0.0
Total Liabilities, Fair Value Disclosure		0.0		0.0
Level 3 [Member] | Long-Lived Assets [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure		0.0	[1]	0.0	[2]
Other Liabilities, Fair Value Disclosure		0.0	[1]	0.0	[2]
Level 3 [Member] | Indefinite-lived Intangible Asset [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure	[3]			154.3
Other Liabilities, Fair Value Disclosure	[3]			0.0
Level 3 [Member] | Designated as Hedging Instrument [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		0.0		0.0
Derivative Liability, Fair Value		0.0		0.0
Level 3 [Member] | Not Designated as Hedging [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		0.0		0.0
Derivative Liability, Fair Value		0.0		0.0
Marketable Investments [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure		174.2	[4],[5]	10.9	[6],[7]
Other Liabilities, Fair Value Disclosure		0.0	[4],[5]	0.0	[6],[7]
Marketable Investments [Member] | Level 1 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure		8.4	[4],[5]	8.3	[6],[7]
Other Liabilities, Fair Value Disclosure		0.0	[4],[5]	0.0	[6],[7]
Marketable Investments [Member] | Level 2 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure		165.8	[4],[5]	2.6	[6],[7]
Other Liabilities, Fair Value Disclosure		0.0	[4],[5]	0.0	[6],[7]
Marketable Investments [Member] | Level 3 [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other Assets, Fair Value Disclosure		0.0	[4],[5]	0.0	[6],[7]
Other Liabilities, Fair Value Disclosure		0.0	[4],[5]	0.0	[6],[7]
Interest Rate Contracts [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		8.5		4.0
Derivative Liability, Fair Value		(3.0)		0.0
Interest Rate Contracts [Member] | Designated as Hedging Instrument [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		7.7	[5],[8]	4.0	[7],[9]
Derivative Liability, Fair Value		(3.0)	[5],[8]	0.0	[7],[9]
Interest Rate Contracts [Member] | Level 1 [Member] | Designated as Hedging Instrument [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		0.0	[5],[8]	0.0	[7],[9]
Derivative Liability, Fair Value		0.0	[5],[8]	0.0	[7],[9]
Interest Rate Contracts [Member] | Level 2 [Member] | Designated as Hedging Instrument [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		7.7	[5],[8]	4.0	[7],[9]
Derivative Liability, Fair Value		(3.0)	[5],[8]	0.0	[7],[9]
Interest Rate Contracts [Member] | Level 3 [Member] | Designated as Hedging Instrument [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		0.0	[5],[8]	0.0	[7],[9]
Derivative Liability, Fair Value		0.0	[5],[8]	0.0	[7],[9]
Foreign Exchange Contracts [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		25.4		25.9
Derivative Liability, Fair Value		(13.7)		(65.3)
Foreign Exchange Contracts [Member] | Designated as Hedging Instrument [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		12.2	[10],[11]	25.5	[12],[13]
Derivative Liability, Fair Value		(12.2)	[10],[11]	(23.3)	[12],[13]
Foreign Exchange Contracts [Member] | Not Designated as Hedging [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		13.2	[10],[11]	0.4	[12],[13]
Derivative Liability, Fair Value		(1.5)	[10],[11]	(42.0)	[12],[13]
Foreign Exchange Contracts [Member] | Level 1 [Member] | Designated as Hedging Instrument [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		0.0	[10],[11]	0.0	[12],[13]
Derivative Liability, Fair Value		0.0	[10],[11]	0.0	[12],[13]
Foreign Exchange Contracts [Member] | Level 1 [Member] | Not Designated as Hedging [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		0.0	[10],[11]	0.0	[12],[13]
Derivative Liability, Fair Value		0.0	[10],[11]	0.0	[12],[13]
Foreign Exchange Contracts [Member] | Level 2 [Member] | Designated as Hedging Instrument [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		12.2	[10],[11]	25.5	[12],[13]
Derivative Liability, Fair Value		(12.2)	[10],[11]	(23.3)	[12],[13]
Foreign Exchange Contracts [Member] | Level 2 [Member] | Not Designated as Hedging [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		13.2	[10],[11]	0.4	[12],[13]
Derivative Liability, Fair Value		(1.5)	[10],[11]	(42.0)	[12],[13]
Foreign Exchange Contracts [Member] | Level 3 [Member] | Designated as Hedging Instrument [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		0.0	[10],[11]	0.0	[12],[13]
Derivative Liability, Fair Value		0.0	[10],[11]	0.0	[12],[13]
Foreign Exchange Contracts [Member] | Level 3 [Member] | Not Designated as Hedging [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		0.0	[10],[11]	0.0	[12],[13]
Derivative Liability, Fair Value		0.0	[10],[11]	0.0	[12],[13]
Equity Contracts [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		2.4
Derivative Liability, Fair Value		0.0
Commodity Contracts [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		4.4		10.1
Derivative Liability, Fair Value		(22.2)		(59.4)
Commodity Contracts [Member] | Not Designated as Hedging [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		4.3	[11],[14]	10.1	[13],[15]
Derivative Liability, Fair Value		(22.2)	[11],[14]	(59.4)	[13],[15]
Commodity Contracts [Member] | Level 1 [Member] | Not Designated as Hedging [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		2.6	[11],[14]	7.2	[13],[15]
Derivative Liability, Fair Value		(0.6)	[11],[14]	0.0	[13],[15]
Commodity Contracts [Member] | Level 2 [Member] | Not Designated as Hedging [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		1.7	[11],[14]	2.9	[13],[15]
Derivative Liability, Fair Value		(21.6)	[11],[14]	(59.4)	[13],[15]
Commodity Contracts [Member] | Level 3 [Member] | Not Designated as Hedging [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		0.0	[11],[14]	0.0	[13],[15]
Derivative Liability, Fair Value		0.0	[11],[14]	0.0	[13],[15]
Grain Contracts [Member] | Not Designated as Hedging [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		1.8	[11],[14]	3.3	[13],[15]
Derivative Liability, Fair Value		(5.5)	[11],[14]	(7.8)	[13],[15]
Grain Contracts [Member] | Level 1 [Member] | Not Designated as Hedging [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		0.0	[11],[14]	0.0	[13],[15]
Derivative Liability, Fair Value		0.0	[11],[14]	0.0	[13],[15]
Grain Contracts [Member] | Level 2 [Member] | Not Designated as Hedging [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		1.8	[11],[14]	3.3	[13],[15]
Derivative Liability, Fair Value		(5.5)	[11],[14]	(7.8)	[13],[15]
Grain Contracts [Member] | Level 3 [Member] | Not Designated as Hedging [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Derivative Asset, Fair Value		0.0	[11],[14]	0.0	[13],[15]
Derivative Liability, Fair Value		$ 0.0	[11],[14]	$ 0.0	[13],[15]

[1] We recorded $11.4 million in non-cash impairment charges in fiscal 2016 to write down certain long-lived assets to their fair value. Fair value was based on recently reported transactions for similar assets in the marketplace. These assets had a carrying value of $28.2 million and were associated with the restructuring actions described in Note 4.

[2] We recorded $30.3 million in non-cash impairment charges in fiscal 2015 to write down certain long-lived assets to their fair value. Fair value was based on recently reported transactions for similar assets in the marketplace. These assets had a carrying value of $68.1 million and were associated with the restructuring actions described in Note 4.

[3] We recorded a $260.0 million non-cash impairment charge in fiscal 2015 to write down our Green Giant brand asset to its fair value of $154.3 million. This asset had a carrying value of $414.3 million. See Note 6 for additional information.

[4] Based on prices of common stock and bond matrix pricing.

[5] These contracts and investments are recorded as prepaid expenses and other current assets, other assets, other current liabilities or other liabilities, as appropriate, based on whether in a gain or loss position. Certain marketable investments are recorded as cash and cash equivalents.

[6] Based on prices of common stock and bond matrix pricing.

[7] These contracts and investments are recorded as prepaid expenses and other current assets, other assets, other current liabilities or other liabilities, as appropriate, based on whether in a gain or loss position. Certain marketable investments are recorded as cash and cash equivalents.

[8] Based on LIBOR and swap rates.

[9] Based on LIBOR and swap rates.

[10] Based on observable market transactions of spot currency rates and forward currency prices.

[11] These contracts are recorded as prepaid expenses and other current assets or as other current liabilities, as appropriate, based on whether in a gain or loss position.

[12] Based on observable market transactions of spot currency rates and forward currency prices.

[13] These contracts are recorded as prepaid expenses and other cu rrent assets or as other current liabilities, as appropriate, based on whether in a gain or loss position.

[14] Based on prices of futures exchanges and rece ntly reported transactions in the marketplace.

[15] Based on prices of futures exchanges and recentl y reported transactions in the marketplace.