| 
           Operating and Reporting Segments Operating and Reporting Segments (Details 1) (USD $) 
        In Thousands, unless otherwise specified  | 
        3 Months Ended | |
|---|---|---|
| 
           Mar. 31, 2015 
         | 
        
           Mar. 31, 2014 
         | 
      |
| Segment Reporting Information [Line Items] | ||
| Land closing revenue | $ 1,439us-gaap_LandSales | $ 2,566us-gaap_LandSales | 
| Homebuilding [Member] | Operating Segments [Member] | ||
| Segment Reporting Information [Line Items] | ||
| Land closing revenue | 
1,439us-gaap_LandSales / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mth_HomebuildingMember  | 
        
2,566us-gaap_LandSales / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mth_HomebuildingMember  | 
      
| Homebuilding, West Region [Member] | Reportable Subsegments [Member] | Homebuilding [Member] | Operating Segments [Member] | ||
| Segment Reporting Information [Line Items] | ||
| Land closing revenue | 
0us-gaap_LandSales / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mth_HomebuildingMember / us-gaap_SubsegmentsAxis = mth_HomebuildingWestRegionMember / us-gaap_SubsegmentsConsolidationItemsAxis = us-gaap_ReportableSubsegmentsMember  | 
        
1,050us-gaap_LandSales / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mth_HomebuildingMember / us-gaap_SubsegmentsAxis = mth_HomebuildingWestRegionMember / us-gaap_SubsegmentsConsolidationItemsAxis = us-gaap_ReportableSubsegmentsMember  | 
      
| Homebuilding, Central Region [Member] | Reportable Subsegments [Member] | Homebuilding [Member] | Operating Segments [Member] | ||
| Segment Reporting Information [Line Items] | ||
| Land closing revenue | 
1,439us-gaap_LandSales / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mth_HomebuildingMember / us-gaap_SubsegmentsAxis = mth_HomebuildingCentralRegionMember / us-gaap_SubsegmentsConsolidationItemsAxis = us-gaap_ReportableSubsegmentsMember  | 
        
1,516us-gaap_LandSales / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mth_HomebuildingMember / us-gaap_SubsegmentsAxis = mth_HomebuildingCentralRegionMember / us-gaap_SubsegmentsConsolidationItemsAxis = us-gaap_ReportableSubsegmentsMember  | 
      
| Homebuilding, East Region [Member] | Reportable Subsegments [Member] | Homebuilding [Member] | Operating Segments [Member] | ||
| Segment Reporting Information [Line Items] | ||
| Land closing revenue | 
$ 0us-gaap_LandSales / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mth_HomebuildingMember / us-gaap_SubsegmentsAxis = mth_HomebuildingEastRegionMember / us-gaap_SubsegmentsConsolidationItemsAxis = us-gaap_ReportableSubsegmentsMember  | 
        
$ 0us-gaap_LandSales / us-gaap_ConsolidationItemsAxis = us-gaap_OperatingSegmentsMember / us-gaap_StatementBusinessSegmentsAxis = mth_HomebuildingMember / us-gaap_SubsegmentsAxis = mth_HomebuildingEastRegionMember / us-gaap_SubsegmentsConsolidationItemsAxis = us-gaap_ReportableSubsegmentsMember  | 
      
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          Revenue from the sale of land in the reporting period. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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