DISCONTINUED OPERATIONS - Schedule of Key Components of Income from Discontinued Operations (Details) - WK Kellogg Co - Discontinued Operations - USD ($) $ in Millions	3 Months Ended	6 Months Ended
	Jul. 01, 2023	Jul. 01, 2023
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Net sales - discontinued operations	$ 690	$ 1,401
Costs of goods sold - discontinued operations	451	936
Selling, general and administrative expense - discontinued operations	147	280
Operating profit - discontinued operations	92	185
Interest expense - discontinued operations	9	19
Other income (expense), net - discontinued operations	8	17
Income from discontinued operations before income taxes	91	183
Income taxes - discontinued operations	27	51
Net income from discontinued operations, net of tax	$ 64	$ 132