Debt Instrument, Par Price Percentage

No definition available.

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

- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

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+ Details

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

- Definition

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

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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.

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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.

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+ Details

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

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
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Balance Type:
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- Details

Name:	us-gaap_DebtInstrumentAxis=mdc_SeniorNotes5Point5PercentDueJanuary2024Member
Namespace Prefix:
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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Balance Type:
Period Type:

- Details

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

- Details

Name:	us-gaap_DebtInstrumentAxis=mdc_SeniorNotes6PercentDueJanuary2043Member
Namespace Prefix:
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Balance Type:
Period Type:

- Details

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

Senior Notes - Carrying Amount of Senior Notes (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Aug. 31, 2021	Jan. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Carrying Amount	$ 1,607,658,000		$ 1,607,658,000				$ 1,037,391,000
Loss on debt retirement	12,150,000	$ 0	$ 12,150,000	$ 0
Senior Notes
Debt Instrument [Line Items]
Loss on debt retirement	$ 12,200,000
5.500% Senior Notes due January 2024, net
Debt Instrument [Line Items]
Interest rate, stated percentage	5.50%		5.50%
Carrying Amount	$ 126,071,000		$ 126,071,000				249,233,000
Debt instrument, face amount	250,000,000		$ 250,000,000
Early repayment of senior debt	$ 123,600,000
5.500% Senior Notes due January 2024, net \| Senior Notes
Debt Instrument [Line Items]
Interest rate, stated percentage	5.50%		5.50%
Early repayment of senior debt	$ 123,600,000
3.850% Senior Notes due January 2030, net
Debt Instrument [Line Items]
Interest rate, stated percentage	3.85%		3.85%
Carrying Amount	$ 297,638,000		$ 297,638,000				297,458,000
Debt instrument, face amount	$ 300,000,000		$ 300,000,000
2.500% Senior Notes due January 2031, net
Debt Instrument [Line Items]
Interest rate, stated percentage	2.50%		2.50%
Carrying Amount	$ 347,055,000		$ 347,055,000				0
Debt instrument, face amount	$ 350,000,000		$ 350,000,000
2.500% Senior Notes due January 2031, net \| Senior Notes
Debt Instrument [Line Items]
Interest rate, stated percentage						2.50%
Debt instrument, face amount						$ 350,000,000
Par price percentage						100.00%
6.000% Senior Notes due January 2043, net
Debt Instrument [Line Items]
Interest rate, stated percentage	6.00%		6.00%
Carrying Amount	$ 490,851,000		$ 490,851,000				490,700,000
Debt instrument, face amount	$ 500,000,000		$ 500,000,000
3.966% Senior Notes due August 2061, net
Debt Instrument [Line Items]
Interest rate, stated percentage	3.966%		3.966%
Carrying Amount	$ 346,043,000		$ 346,043,000				$ 0
Debt instrument, face amount	$ 350,000,000		$ 350,000,000
3.966% Senior Notes due August 2061, net \| Senior Notes
Debt Instrument [Line Items]
Interest rate, stated percentage					3.966%
Debt instrument, face amount					$ 350,000,000
Par price percentage					100.00%