v3.25.4

Income Taxes - Summary of Changes in Valuation Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024
Valuation Allowance [Line Items]
Valuation allowance, beginning of period	$ 81,798	$ 78,689
The impact of changes in foreign exchange rates	3,081	1,587
Valuation allowance, end of period	198,777	81,798
United States
Valuation Allowance [Line Items]
Valuation Allowance - increase (decrease) amount	20,435	8,727
Germany
Valuation Allowance [Line Items]
Valuation Allowance - increase (decrease) amount	13,515	0
Canada
Valuation Allowance [Line Items]
Valuation Allowance - increase (decrease) amount	72,747	(7,815)
Australia
Valuation Allowance [Line Items]
Valuation Allowance - increase (decrease) amount	$ 7,201	$ 610

X

- Definition

The change in the valuation allowance due to the impact of foreign exchange.

+ References

No definition available.

+ Details

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Namespace Prefix:	merc_
Data Type:	xbrli:monetaryItemType
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Period Type:	duration

X

- Definition

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

+ Details

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X

- Definition

Amount of increase (decrease) in the valuation allowance for a specified deferred tax asset.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

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- Definition

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

+ References

No definition available.

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