Stockholders' Equity (Schedule of total comprehensive income) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended								12 Months Ended
	May 25, 2014	Feb. 23, 2014	Nov. 24, 2013	Aug. 25, 2013	May 26, 2013	Feb. 24, 2013	Nov. 25, 2012	Aug. 26, 2012	May 25, 2014	May 26, 2013	May 27, 2012
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments									$ (11.3)	$ 0.8	$ (420.1)
Net actuarial gain (loss)									206.0	45.0	(504.6)
Other fair value changes:
Securities									0.3	0.8	(0.2)
Hedge derivatives									5.0	24.6	(53.4)
Reclassification to earnings:
Hedge derivatives									(4.6)	12.2	11.5
Amortization of losses and prior service costs									107.6	98.8	81.7
Other comprehensive income (loss), net of tax									303.0	182.2	(885.1)
Comprehensive Income:
Net earnings attributable to General Mills	404.6	410.6	549.9	459.3	366.3	398.4	541.6	548.9	1,824.4	1,855.2	1,567.3
Total comprehensive income (loss) attributable to General Mills									2,069.4	2,013.6	834.4
General Mills [Member]
Other comprehensive income (loss), before tax:
Foreign currency translation adjustments									(71.8)	(19.8)	(270.3)
Net actuarial gain (loss)									327.2	76.3	(813.1)
Other fair value chages:
Securities									0.5	1.2	(0.3)
Hedge derivaties									14.4	33.5	(80.8)
Reclassification to earnings:
Hedge derivatives									(4.7)	15.0	16.3
Amortization of losses and prior service costs									172.7	159.9	131.6
Other comprehensive income (loss), before tax									438.3	266.1	(1,016.6)
Other comprehensive income (loss), tax:
Foreign currency translation adjustments									0	0	0
Net actuarial gain									(121.2)	(31.3)	308.5
Other fair value changes:
Securities									(0.2)	(0.4)	0.1
Hedge derivatives									(7.0)	(10.4)	31.2
Reclassification to earnings:
Hedge derivatives									0.2	(4.5)	(6.2)
Amortization of losses and prior service costs									(65.1)	(61.1)	(49.9)
Other Comprehensive Income (Loss), Tax									(193.3)	(107.7)	283.7
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments									(71.8)	(19.8)	(270.3)
Net actuarial gain (loss)									206.0	45.0	(504.6)
Other fair value changes:
Securities									0.3	0.8	(0.2)
Hedge derivatives									7.4	23.1	(49.6)
Reclassification to earnings:
Hedge derivatives									(4.5)	10.5	10.1
Amortization of losses and prior service costs									107.6	98.8	81.7
Other comprehensive income (loss), net of tax									245.0	158.4	(732.9)
Comprehensive Income:
Net earnings attributable to General Mills									1,824.4	1,855.2	1,567.3
Total comprehensive income (loss) attributable to General Mills									2,069.4	2,013.6	834.4
Noncontrolling Interest [Member]
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments									19.1	10.3	(51.1)
Net actuarial gain (loss)									0	0	0
Other fair value changes:
Securities									0	0	0
Hedge derivatives									0	0	0
Reclassification to earnings:
Hedge derivatives									0	0	0
Amortization of losses and prior service costs									0	0	0
Other comprehensive income (loss), net of tax									19.1	10.3	(51.1)
Comprehensive Income:
Net earnings attributable to noncontrolling interests									5.8	8.0	6.8
Total comprehensive income (loss) attributable to noncontrolling interests									24.9	18.3	(44.3)
Redeemable Interest [Member]
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments									41.4	10.3	(98.7)
Net actuarial gain (loss)									0	0	0
Other fair value changes:
Securities									0	0	0
Hedge derivatives									(2.4)	1.5	(3.8)
Reclassification to earnings:
Hedge derivatives									(0.1)	1.7	1.4
Amortization of losses and prior service costs									0	0	0
Other comprehensive income (loss), net of tax									38.9	13.5	(101.1)
Comprehensive Income:
Net earnings attributable to redeemable interest									31.1	29.3	15.0
Total comprehensive income (loss) attributable to redeemable interests									$ 70.0	$ 42.8	$ (86.1)