Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended
	Aug. 30, 2015	Aug. 24, 2014
Statement of Comprehensive Income [Abstract]
Net income (loss), pre-tax amount	$ (1,539.5)	$ 767.2
Net income (loss), tax (expense) benefit	387.1	(282.7)
Net income (loss), after-tax amount	(1,152.4)	484.5
Derivative adjustments:
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	0.1
Unrealized gains on available-for-sale securities, tax (expense) benefit	0.0	0.0
Unrealized gains on available-for-sale securities, after-tax amount	0.0	0.1
Unrealized currency translation losses, pre-tax amount	(37.6)	(17.7)
Unrealized currency translation losses, tax (expense) benefit	0.0	0.0
Unrealized currency translation losses, after-tax amount	(37.6)	(17.7)
Pension and post-employment benefit obligations:
Unrealized pension and post-employment benefit obligations, pre-tax amount	6.6	3.8
Unrealized pension and post-employment benefit obligations, tax (expense) benefit	(1.6)	(1.0)
Unrealized pension and post-employment benefit obligations, after-tax amount	5.0	2.8
Reclassification for pension and post-employment benefit obligations included in net income, pre-tax amount	(1.3)	(0.2)
Reclassification for pension and post-employment benefit obligations included in net income, tax (expense) benefit	0.5	0.1
Reclassification for pension and post-employment benefit obligations included in net income, after-tax amount	(0.8)	(0.1)
Comprehensive income (loss), pre-tax amount	(1,571.8)	752.7
Comprehensive income (loss), tax (expense) benefit	386.0	(283.4)
Comprehensive income (loss), after-tax amount	(1,185.8)	469.3
Comprehensive income (loss) attributable to noncontrolling interests, pre-tax amount	(1.1)	(0.8)
Comprehensive income (loss) attributable to noncontrolling interested, tax (expense) benefit	(0.3)	0.0
Comprehensive income (loss) attributable to noncontrolling interests, after-tax amount	(1.4)	(0.8)
Comprehensive income (loss) attributable to ConAgra Foods, Inc., pre-tax amount	(1,570.7)	753.5
Comprehensive income (loss) attributable to ConAgra Foods, Inc., tax (expense) benefit	386.3	(283.4)
Comprehensive income (loss) attributable to ConAgra Foods, Inc., after-tax amount	$ (1,184.4)	$ 470.1