Fair Value Measurement of Financial Instruments - Additional Information (Detail) - CNY (¥) ¥ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Disclosure of fair value measurement of assets [abstract]
Transfers between the levels of fair value hierarchy	¥ 0	¥ 0

Transfers between different levels of fair value hierarchy.

No definition available.

Name:	chl_TransfersBetweenDifferentLevelsOfFairValueHierarchy
Namespace Prefix:	chl_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration