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Segment Information - Additional Information (Detail) - Segment
12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Dec. 31, 2017
Sales Information [Line Items]      
Number of Reportable Segments 4    
Walmart Inc. and Subsidiaries | Revenue from Contract with Customer | Customer Concentration Risk      
Sales Information [Line Items]      
Percentage of sales by major customer 14.60% 14.60% 14.80%