XML 36 R23.htm IDEA: XBRL DOCUMENT v3.25.3

Financial Instruments (Tables)

9 Months Ended

Sep. 30, 2025

Fair Value Disclosures [Abstract]

Estimated Fair Values of Financial Instruments

The following table presents the fair values of financial instruments:

			September 30, 2025						December 31, 2024
			(Amounts in thousands)
Assets
Investments			$	6,373,605					$	6,076,370
Notes receivable			10,024						31,231
Liabilities
Options sold			599						213
Notes payable			573,172						566,812

X

- Definition

Estimated Fair Values of Financial Instruments [Table Text Block]

+ References

No definition available.

+ Details

Name:	mcy_EstimatedFairValuesOfFinancialInstrumentsTableTextBlock
Namespace Prefix:	mcy_
Data Type:	dtr-types:textBlockItemType
Balance Type:	na
Period Type:	duration

X

- References

No definition available.

+ Details

Name:	us-gaap_FairValueDisclosuresAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration