Stockholders' Equity (Schedule of total comprehensive income) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	May 29, 2016	Feb. 28, 2016	Nov. 29, 2015	Aug. 30, 2015	May 31, 2015	Feb. 22, 2015	Nov. 23, 2014	Aug. 24, 2014	May 29, 2016		May 31, 2015		May 25, 2014
Other comprehensive income (loss), net of tax:
Foreign currency translation									$ (108.7)		$ (957.9)		$ (11.3)
Net actuarial income (loss)									(325.9)		(358.4)		206.0
Other fair value changes:
Securities									0.1		0.8		0.3
Hedge derivatives									16.0		4.1		5.0
Reclassification to earnings:
Hedge derivatives									(9.5)		4.9		(4.6)
Amortization of losses and prior service costs									128.6		105.1		107.6
Other comprehensive income (loss), net of tax									(299.4)		(1,201.4)		303.0
Comprehensive Income:
Net earnings attributable to General Mills	$ 379.6	$ 361.7	$ 529.5	$ 426.6	$ 186.8	$ 343.2	$ 346.1	$ 345.2	1,697.4		1,221.3		1,824.4
Net earnings attributable to redeemable and noncontrolling interests									39.4		38.1		36.9
Total comprehensive income (loss) attributable to General Mills									1,395.9		250.9		2,069.4
General Mills [Member]
Other comprehensive income (loss), before tax:
Foreign currency translation									(107.6)		(727.9)		(71.8)
Net actuarial income (loss)									(514.2)		(561.1)		327.2
Other fair value chages:
Securities									0.2		1.3		0.5
Hedge derivaties									16.5		13.6		14.4
Reclassification to earnings:
Hedge derivatives									(13.5)	[1]	0.7	[2]	(4.7)	[3]
Amortization of losses and prior service costs									206.8	[4]	170.2	[5]	172.7	[6]
Other comprehensive income (loss), before tax									(411.8)		(1,103.2)		438.3
Other comprehensive income (loss), tax:
Foreign currency translation									0.0		0.0		0.0
Net actuarial income (loss)									188.3		202.7		(121.2)
Other fair value changes:
Securities									(0.1)		(0.5)		(0.2)
Hedge derivatives									(2.2)		(4.8)		(7.0)
Reclassification to earnings:
Hedge derivatives									2.5	[1]	0.5	[2]	0.2	[3]
Amortization of losses and prior service costs									(78.2)	[4]	(65.1)	[5]	(65.1)	[6]
Other comprehensive income (loss), tax									110.3		132.8		(193.3)
Other comprehensive income (loss), net of tax:
Foreign currency translation									(107.6)		(727.9)		(71.8)
Net actuarial income (loss)									(325.9)		(358.4)		206.0
Other fair value changes:
Securities									0.1		0.8		0.3
Hedge derivatives									14.3		8.8		7.4
Reclassification to earnings:
Hedge derivatives									(11.0)	[1]	1.2	[2]	(4.5)	[3]
Amortization of losses and prior service costs									128.6	[4]	105.1	[5]	107.6	[6]
Other comprehensive income (loss), net of tax									(301.5)		(970.4)		245.0
Comprehensive Income:
Net earnings attributable to General Mills									1,697.4		1,221.3		1,824.4
Total comprehensive income (loss) attributable to General Mills									1,395.9		250.9		2,069.4
Noncontrolling Interest [Member]
Other comprehensive income (loss), net of tax:
Foreign currency translation									2.8		(78.2)		19.1
Net actuarial income (loss)									0.0		0.0		0.0
Other fair value changes:
Securities									0.0		0.0		0.0
Hedge derivatives									0.0		0.0		0.0
Reclassification to earnings:
Hedge derivatives									0.0	[1]	0.0	[2]	0.0	[3]
Amortization of losses and prior service costs									0.0	[4]	0.0	[5]	0.0	[6]
Other comprehensive income (loss), net of tax									2.8		(78.2)		19.1
Comprehensive Income:
Net earnings attributable to redeemable and noncontrolling interests									8.4		8.2		5.8
Total comprehensive income (loss) attributable to noncontrolling interests									11.2		(70.0)		24.9
Redeemable Interest [Member]
Other comprehensive income (loss), net of tax:
Foreign currency translation									(3.9)		(151.8)		41.4
Net actuarial income (loss)									0.0		0.0		0.0
Other fair value changes:
Securities									0.0		0.0		0.0
Hedge derivatives									1.7		(4.7)		(2.4)
Reclassification to earnings:
Hedge derivatives									1.5	[1]	3.7	[2]	(0.1)	[3]
Amortization of losses and prior service costs									0.0	[4]	0.0	[5]	0.0	[6]
Other comprehensive income (loss), net of tax									(0.7)		(152.8)		38.9
Comprehensive Income:
Net earnings attributable to redeemable and noncontrolling interests									31.0		29.9		31.1
Total comprehensive income (loss) attributable to redeemable interests									$ 30.3		$ (122.9)		$ 70.0

[1] Gain reclassified from AOCI into earnings is reported in interest, net for interest rate swaps and in cost of sales and SG&A expenses for foreign exchange contracts.

[2] Loss reclassified from AOCI into earnings is reported in interest, net for interest rate swaps and in cost of sales and SG&A expenses for foreign exchange contracts.

[3] Gain reclassified from AOCI into earnings is reported in interest, net for interest rate swaps and in cost of sales and SG&A expenses for foreign exchange contracts.

[4] Loss reclassified from AOCI into earnings is reported in SG&A expense.

[5] Loss reclassified from AOCI into earnings is reported in SG&A expense.

[6] Loss reclassified from AOCI into earnings is reported in SG&A expense.