Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Nov. 29, 2015	Nov. 23, 2014	Nov. 29, 2015	Nov. 23, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss), pre-tax amount	$ 248.3	$ 114.0	$ (1,291.2)	$ 881.2
Net income (loss), tax (expense) benefit	(89.0)	(98.1)	298.1	(380.8)
Net income (loss), after-tax amount	159.3	15.9	(993.1)	500.4
Other comprehensive income (loss):
Reclassification for derivative adjustments included in net income, pre-tax amount			0.0	(0.5)
Reclassification for derivative adjustments included in net income, tax (expense) benefit			0.0	0.2
Reclassification for derivative adjustments included in net income, after-tax amount			0.0	(0.3)
Unrealized gains on available-for-sale securities, pre-tax amount	0.0	0.2	0.0	0.3
Unrealized gains on available-for-sale securities, tax (expense) benefit	0.0	(0.1)	0.0	(0.1)
Unrealized gains on available-for-sale securities, after-tax amount	0.0	0.1	0.0	0.2
Unrealized currency translation losses, pre-tax amount	(18.4)	(35.1)	(56.0)	(52.8)
Unrealized currency translation losses, tax (expense) benefit	0.0	0.0	0.0	0.0
Unrealized currency translation losses, after-tax amount	(18.4)	(35.1)	(56.0)	(52.8)
Pension and post-employment benefit obligations:
Unrealized pension and post-employment benefit obligations, pre-tax amount	0.0	0.0	6.6	3.8
Unrealized pension and post-employment benefit obligations, tax (expense) benefit	0.0	0.1	(1.6)	(0.9)
Unrealized pension and post-employment benefit obligations, after-tax amount	0.0	0.1	5.0	2.9
Reclassification for pension and post-employment benefit obligations included in net income, pre-tax amount	(1.3)	(0.2)	(2.6)	(0.4)
Reclassification for pension and post-employment benefit obligations included in net income, tax (expense) benefit	0.5	0.0	1.0	0.1
Reclassification for pension and post-employment benefit obligations included in net income, after-tax amount	(0.8)	(0.2)	(1.6)	(0.3)
Comprehensive income (loss), pre-tax amount	228.6	78.9	(1,343.2)	831.6
Comprehensive income (loss), tax (expense) benefit	(88.5)	(98.1)	297.5	(381.5)
Comprehensive income (loss), after-tax amount	140.1	(19.2)	(1,045.7)	450.1
Comprehensive income attributable to noncontrolling interests, pre-tax amount	3.7	4.1	2.6	3.3
Comprehensive income attributable to noncontrolling interested, tax (expense) benefit	(0.2)	0.0	(0.5)	0.0
Comprehensive income attributable to noncontrolling interests, after-tax amount	3.5	4.1	2.1	3.3
Comprehensive income (loss) attributable to ConAgra Foods, Inc., pre-tax amount	224.9	74.8	(1,345.8)	828.3
Comprehensive income (loss) attributable to ConAgra Foods, Inc., tax (expense) benefit	(88.3)	(98.1)	298.0	(381.5)
Comprehensive income (loss) attributable to ConAgra Foods, Inc., after-tax amount	$ 136.6	$ (23.3)	$ (1,047.8)	$ 446.8