The description of the contractual agreement or stated policy for charging the net defined benefit cost, or the fact that there is no such policy, for an entity participating in defined benefit plans that share risks between various entities under common control. [Refer: Defined benefit plans that share risks between entities under common control [member]]

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
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-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2018-03-01&anchor=para_149_a&doctype=Standard
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The description of available information about a surplus or deficit in a multi-employer or state plan that may affect the amount of future contributions. [Refer: Multi-employer defined benefit plans [member]; State defined benefit plans [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2018-01-01
-Paragraph 148
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-URI http://eifrs.ifrs.org/eifrs/XBRL?type=IAS&num=19&date=2018-03-01&anchor=para_148_d_iv&doctype=Standard
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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 decrease (increase) in the net defined benefit liability (asset) resulting from payments from the plan in respect of settlements. [Refer: Gains (losses) arising from settlements, net defined benefit liability (asset); Net defined benefit liability (asset); Defined benefit plans [member]]

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Name IAS
-Number 19
-IssueDate 2018-01-01
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The amount of post-employment benefit expense relating to defined contribution plans. Defined contribution plans are post-employment benefit plans under which an entity pays fixed contributions into a separate entity (a fund) and will have no legal or constructive obligation to pay further contributions if the fund does not hold sufficient assets to pay all employee benefits relating to employee service in the current and prior periods.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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-IssueDate 2018-01-01
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Employee profit sharing amount.

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Fixed amount per hour for each covered employees.

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Percentage of collective bargaining agreements.

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No definition available.

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Percentage payment of workers daily integrated salary.

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Percentage share of employers profits.

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Employee benefits (Narrative) (Details) $ / shares in Units, $ in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) $ / shares	Dec. 31, 2018 MXN ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2017 MXN ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2016 MXN ($)
Disclosure of defined benefit plans [line items]
Percentage of collective bargaining agreements	43.00%	43.00%	44.00%	44.00%
Percentage share of employers profits	10.00%	10.00%
Employee profit sharing amount		$ 67		$ 0
Percentage payment of workers daily integrated salary	2.00%	2.00%
Defined contribution plan expense		$ 13,687		12,838		$ 11,323
Benefits paid		$ (327)		$ (12,517)
Republic employees [Member]
Disclosure of defined benefit plans [line items]
Percentage of collective bargaining agreements	81.00%	81.00%
Agreement description	The agreement initially expired on August 15, 2016 and was extended for a further three years through August 15, 2019.	The agreement initially expired on August 15, 2016 and was extended for a further three years through August 15, 2019.
Company's quarterly contributions	The extended agreement provides the Company’s quarterly contributions to fund the Republic Retirement VEBA and Benefit Trust (the “Benefit Trust”) to be reduced from $2.6 million to $0.25 million beginning in August 15, 2016 through June 30, 2019. Effective July 1, 2019, the Company’s contribution to the Benefit Trust will change to $4.00 per hour for each hour worked by USW represented employees.	The extended agreement provides the Company’s quarterly contributions to fund the Republic Retirement VEBA and Benefit Trust (the “Benefit Trust”) to be reduced from $2.6 million to $0.25 million beginning in August 15, 2016 through June 30, 2019. Effective July 1, 2019, the Company’s contribution to the Benefit Trust will change to $4.00 per hour for each hour worked by USW represented employees.
Fixed amount per hour for each covered employees \| $ / shares	$ 1.68
VEBA Benefit Trust [Member]
Disclosure of defined benefit plans [line items]
Agreement description	The cost contributions to these two funds have been reduced from USD $ 2.6 million to USD$ 0.25 million per quarter effective after the review of the collective agreement on August 16 2016.	The cost contributions to these two funds have been reduced from USD $ 2.6 million to USD$ 0.25 million per quarter effective after the review of the collective agreement on August 16 2016.
VEBA Benefit Trust [Member] \| USD [Member]
Disclosure of defined benefit plans [line items]
Defined contribution plan expense	$ 1,000		$ 6,900		$ 10,400
401(k) Plans [Member] \| USD [Member]
Disclosure of defined benefit plans [line items]
Defined contribution plan expense	$ 1,000		800		700
Profit Sharing and Incentive Compensation Plans [Member]
Disclosure of defined benefit plans [line items]
Agreement description	The labor agreement includes a profit sharing plan to which the Company is required to contribute The extended agreement modified the plan to the following quarterly pretax income, as defined in the labor agreement ("EBT"): 3% of EBT between $0 and $25 million per quarter; 4% of EBT between $25 and $75 million per quarter; and 5% of EBT over $75 million per quarter.	The labor agreement includes a profit sharing plan to which the Company is required to contribute The extended agreement modified the plan to the following quarterly pretax income, as defined in the labor agreement ("EBT"): 3% of EBT between $0 and $25 million per quarter; 4% of EBT between $25 and $75 million per quarter; and 5% of EBT over $75 million per quarter.
Profit Sharing and Incentive Compensation Plans [Member] \| USD [Member]
Disclosure of defined benefit plans [line items]
Defined contribution plan expense	$ 1,000		1,000		1,000
Benefits paid	800		900		600
Republic [Member] \| USD [Member]
Disclosure of defined benefit plans [line items]
Defined contribution plan expense	$ 3,600		$ 3,500		$ 10,000