Estimated Performance Based Stock Option Grant Expense Maximum

No definition available.

Name:	mdc_EstimatedPerformanceBasedStockOptionGrantExpenseMaximum
Namespace Prefix:	mdc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Home Gross Margin

+ References

No definition available.

+ Details

Name:	mdc_HomeGrossMargin
Namespace Prefix:	mdc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percent Increase In Total Revenue

+ References

No definition available.

+ Details

Name:	mdc_PercentIncreaseInTotalRevenue
Namespace Prefix:	mdc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Stock Based Comp Expense Recorded On Executive Performance Based Stock Option Grants

+ References

No definition available.

+ Details

Name:	mdc_StockBasedCompExpenseRecordedOnExecutivePerformanceBasedStockOptionGrants
Namespace Prefix:	mdc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of equity-based compensation, related to restricted stock units or restricted stock awards, recognized as expense or an asset, if compensation is capitalized.

+ References

No definition available.

+ Details

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

- Definition

This element represents the amount of recognized equity-based compensation related to stock options during the period, that is, the amount recognized as expense in the income statement (or as asset if compensation is capitalized).

+ References

No definition available.

+ Details

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

- Definition

Description of award terms as to how many shares or portion of an award are no longer contingent on satisfaction of either a service condition, market condition or a performance condition, thereby giving the employee the legal right to convert the award to shares, to sell the shares, and be entitled to the cash proceeds of such sale. For example, vesting may be expressed as being 25 percent of the shares under option on each anniversary of the grant date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

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

- Details

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

- Definition

The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(3)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph c(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (d)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

As of the balance sheet date, the number of shares into which fully vested and expected to vest stock options outstanding can be converted under the option plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (e)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph d(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsVestedAndExpectedToVestOutstandingNumber
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant

Stock Based Compensation - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	1 Months Ended	3 Months Ended		9 Months Ended
	Mar. 08, 2012	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Recognized option awards		$ 3.6	$ 3.1	$ 8.4	$ 7.3
Recognized restricted stock grants		1.3	2.3	4.3	4.8
Options vesting per year	One third
Compensation expense recognized		1.8		4.3
Grant date fair value	$ 7.42
Year 1 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option shares vest	166,667
Year 2 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option shares vest	166,667
Year 3 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option shares vest	166,666
Chief Executive Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Long term performance-based non-qualified stock option grants	500,000
Chief Operating Officer [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Long term performance-based non-qualified stock option grants	500,000
Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Home gross margin	16.70%
Minimum [Member] \| Year 1 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in total revenue over 2011	10.00%
Minimum [Member] \| Year 2 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in total revenue over 2011	15.00%
Minimum [Member] \| Year 3 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in total revenue over 2011	20.00%
Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Potential expense that would be recognized if all of the performance targets are met	$ 7.4