v3.25.4

Net Loss Per Common Share - Reconciliation of Basic and Diluted Net Loss Per Common Share (Parenthetical) (Details) - shares	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Restricted Stock
Net Income Per Common Share Basic And Diluted [Line Items]
Antidilutive securities excluded from computation of basic earnings per share amount	111,732	21,054	54,227

X

- Definition

Antidilutive securities excluded from computation of basic earnings per share amount.

+ References

No definition available.

+ Details

Name:	merc_AntidilutiveSecuritiesExcludedFromComputationOfBasicEarningsPerShareAmount
Namespace Prefix:	merc_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

X

- Definition

Net Income Per Share Attributable To Common Shareholders Basic And Diluted [Line Items]

+ References

No definition available.

+ Details

Name:	merc_NetIncomePerShareAttributableToCommonShareholdersBasicAndDilutedLineItems
Namespace Prefix:	merc_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Details

Name:	us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis=us-gaap_RestrictedStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: