Stockholders' Equity (Schedule of total comprehensive income (loss)) (Details) - USD ($) $ in Millions		3 Months Ended		12 Months Ended
		Aug. 28, 2016	Aug. 30, 2015	May 29, 2016
Net earnings attributable to General Mills		$ 409.0	$ 426.6
Net earnings (loss) attributable to redeemable and noncontrolling interests		10.5	8.5
Other Comprehensive Income (Loss), Net of Tax:
Foreign currency translation		80.4	(142.2)
Other fair value changes:
Securities		0.4	(0.1)
Hedge derivatives		15.2	10.3
Reclassification to earnings:
Hedge derivatives	[1]	(2.8)	0.7
Amortization of losses and prior service costs	[2]	30.6	30.9
Other comprehensive income (loss), net of tax		123.8	(100.4)
Total comprehensive income (loss) attributable to General Mills		536.5	317.1
General Mills [Member]
Net earnings attributable to General Mills		409.0	426.6
Other Comprehensive Income (Loss), Pretax:
Foreign currency translation		86.6	(149.9)
Other fair value changes:
Securities		0.6	(0.1)
Hedge derivatives		10.2	13.2
Reclassification to earnings:
Hedge derivatives	[1]	(1.6)	(1.1)
Amortization of losses and prior service costs	[2]	49.4	49.7
Other comprehensive income (loss), before tax		145.2	(88.2)
Other Comprehensive Income (Loss), Tax:
Foreign currency translation		0.0	0.0
Other fair value changes:
Securities		(0.2)	0.0
Hedge derivatives		1.9	(3.1)
Reclassification to earnings:
Hedge derivatives	[1]	(0.6)	0.6
Amortization of losses and prior service costs	[2]	(18.8)	(18.8)
Other comprehensive income (loss), tax		(17.7)	(21.3)
Other Comprehensive Income (Loss), Net of Tax:
Foreign currency translation		86.6	(149.9)
Other fair value changes:
Securities		0.4	(0.1)
Hedge derivatives		12.1	10.1
Reclassification to earnings:
Hedge derivatives	[1]	(2.2)	(0.5)
Amortization of losses and prior service costs	[2]	30.6	30.9
Other comprehensive income (loss), net of tax		127.5	(109.5)
Total comprehensive income (loss) attributable to General Mills		536.5	317.1
Noncontrolling Interests [Member]
Net earnings (loss) attributable to redeemable and noncontrolling interests		1.8	2.6
Other Comprehensive Income (Loss), Net of Tax:
Foreign currency translation		2.8	5.3
Other fair value changes:
Securities		0.0	0.0
Hedge derivatives		0.0	0.0
Reclassification to earnings:
Hedge derivatives	[1]	0.0	0.0
Amortization of losses and prior service costs	[2]	0.0	0.0
Other comprehensive income (loss), net of tax		2.8	5.3
Total comprehensive income (loss) attributable to noncontrolling interests		4.6	7.9
Redeemable Interests [Member]
Net earnings (loss) attributable to redeemable and noncontrolling interests		8.7	5.9
Other Comprehensive Income (Loss), Net of Tax:
Foreign currency translation		(9.0)	2.4
Other fair value changes:
Securities		0.0	0.0
Hedge derivatives		3.1	0.2
Reclassification to earnings:
Hedge derivatives	[1]	(0.6)	1.2
Amortization of losses and prior service costs	[2]	0.0	0.0
Other comprehensive income (loss), net of tax		(6.5)	3.8
Total comprehensive income (loss) attributable to redeemable interests		$ 2.2	$ 9.7	$ 30.3

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

[2] Loss reclassified from AOCI into earnings is reported in SG&A expenses.