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Segment Information, Nature of Operations, and Certain Concentrations - Additional Information (Detail) | 12 Months Ended
--- | ---
Dec. 31, 2012 Joint_Ventures MetropolitanArea
Segment Reporting Information [Line Items] |
Number of metropolitan areas Ryan Homes product are sold | 27
Number of consolidated joint ventures | 1
Revenue derived from Washington, D.C. and Baltimore, MD metropolitan areas | 47.00%
Homebuilding [Member] |
Segment Reporting Information [Line Items] |
Number of reportable segments | 4
Mortgage Banking [Member] |
Segment Reporting Information [Line Items] |
Number of reportable segments | 1

X
- Definition Number of consolidated joint ventures. + References No definition available. + Details
Name: | nvr_NumberOfConsolidatedJointVentures
Namespace Prefix: | nvr_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of metropolitan areas that Ryan Homes products are sold in. + References No definition available. + Details
Name: | nvr_NumberOfMetropolitanAreasSales
Namespace Prefix: | nvr_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Percentage of homebuilding revenue derived from Washington, D.C. and Baltimore, MD metropolitan areas. + References No definition available. + Details
Name: | nvr_PercentageOfRevenueFromDcAndBaltimoreAreas
Namespace Prefix: | nvr_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements. + References No definition available. + Details
Name: | us-gaap_NumberOfReportableSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_SegmentReportingInformationLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration