Number of shares available to underwriters.

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Proceeds from Disposal of Discontinued Operations

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Line items represent concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes of the table.

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The gain (loss) recognised on the measurement to fair value less costs to sell or on the disposal of the assets or disposal group(s) constituting the discontinued operation. [Refer: Discontinued operations [member]]

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The number of instruments or interests issued or issuable at acquisition date for equity interests of the acquirer transferred as consideration in a business combination.

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The cash inflow from the disposal of non-current assets or disposal groups classified as held for sale and discontinued operations. [Refer: Discontinued operations [member]; Disposal groups classified as held for sale [member]; Non-current assets or disposal groups classified as held for sale]

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The proportion of ownership interest in an associate attributable to the entity. [Refer: Associates [member]]

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The weighted average share price. [Refer: Weighted average [member]]

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Equity Accounted Investees, Other Investments and Non-Current Accounts Receivable - Additional Information (Detail)			12 Months Ended
	Sep. 28, 2017 MXN ($) shares	Jan. 25, 2017 MXN ($) shares	Dec. 31, 2017	Dec. 31, 2016
Disclosure of detailed information about financial instruments [line items]
Number of shares available for underwriters \| shares		9,976,087
Bottom of range [member]
Disclosure of detailed information about financial instruments [line items]
Share price		$ 95.00
Top of range [member]
Disclosure of detailed information about financial instruments [line items]
Share price		115.00
Camcem [member]
Disclosure of detailed information about financial instruments [line items]
Ownership percentage			40.10%	10.30%
Camcem [member] \| Disposal groups classified as held for sale [member]
Disclosure of detailed information about financial instruments [line items]
Ownership percentage	20.00%
Camsa [member]
Disclosure of detailed information about financial instruments [line items]
Ownership percentage				49.00%
GCC [member]
Disclosure of detailed information about financial instruments [line items]
Ownership percentage	9.47%		23.00%
Share price		95.00
Gain (loss) on sale of business	$ 1,682,000,000	$ 1,859,000,000
Number of shares sold \| shares	31,483,332
Proceeds from sale	$ 3,012,000,000
GCC [member] \| Private Placements Offering [Member]
Disclosure of detailed information about financial instruments [line items]
Ownership percentage		13.53%
Number of shares issued		76,483,332
Proceeds from sale of common stock		$ 4,094