STOCKHOLDERS' EQUITY: - Directors' Stock Award Plan (Details) - shares	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
Parent Company (Grupo Mexico) common shares
Activity in directors' stock award plan
Treasury stock balance at the end of the period (in shares)	96,570,902	101,574,318
Directors' Stock Award Plan
Share based Compensation Plan
Common shares received on election as director	1,200
Additional shares issued at each annual general meeting	1,200
Total SCC shares reserved for the plan	600,000
Period of extension of plan	5 years
Increased share awards issued to directors	1,600