The debt instrument par price percent.

No definition available.

Name:	mdc_DebtInstrumentParPricePercentage
Namespace Prefix:	mdc_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
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+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix:	us-gaap_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	instant

- 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.

+ Details

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

- Definition

The cash outflow for the extinguishment of long-term borrowing, with the highest claim on the assets of the entity in case of bankruptcy or liquidation, before its maturity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
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+ Details

Name:	us-gaap_EarlyRepaymentOfSeniorDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Difference between the fair value of payments made and the carrying amount of debt which is extinguished prior to maturity.

+ References

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-Publisher FASB
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+ Details

Name:	us-gaap_GainsLossesOnExtinguishmentOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=mdc_SeniorNotes2500DueJanuary2031Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=mdc_SeniorNotes3966DueAugust2061Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=mdc_SeniorNotes5500DueJanuary2024Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Senior Notes - Narrative (Details) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
Senior Notes - Narrative (Details) - USD ($)	Sep. 30, 2022	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Aug. 31, 2021	Jan. 31, 2021
Debt Instrument [Line Items]
Loss on debt retirement		$ 0	$ 12,150,000	$ 0	$ 12,150,000
Senior Notes
Debt Instrument [Line Items]
Loss on debt retirement	$ 12,200,000
Senior Notes 2.500% Due January 2031
Debt Instrument [Line Items]
Debt instrument, face amount	$ 350,000,000	$ 350,000,000		$ 350,000,000			$ 350,000,000
Interest rate, stated percentage	2.50%	2.50%		2.50%			2.50%
Par price percentage							100.00%
Senior Notes 3.966% Due August 2061
Debt Instrument [Line Items]
Debt instrument, face amount	$ 350,000,000	$ 350,000,000		$ 350,000,000		$ 350,000,000
Interest rate, stated percentage	3.966%	3.966%		3.966%		3.966%
Par price percentage						100.00%
Senior Notes 5.500% Due January 2024
Debt Instrument [Line Items]
Interest rate, stated percentage						5.50%
Senior Notes 5.500% Due January 2024 \| Senior Notes
Debt Instrument [Line Items]
Interest rate, stated percentage	5.50%	5.50%		5.50%
Early repayment of senior debt	$ 123,600,000