| 
           Real Estate and Capitalized Interest (Details 2) (USD $) 
        In Thousands, unless otherwise specified  | 
        3 Months Ended | ||||||
|---|---|---|---|---|---|---|---|
| 
           Mar. 31, 2015 
         | 
        
           Mar. 31, 2014 
         | 
        
           Dec. 31, 2014 
         | 
      |||||
| Summary of capitalized interest | |||||||
| Capitalized interest, beginning of period | $ 54,060us-gaap_RealEstateInventoryCapitalizedInterestCosts | $ 32,992us-gaap_RealEstateInventoryCapitalizedInterestCosts | |||||
| Interest incurred | 15,282us-gaap_RealEstateInventoryCapitalizedInterestCostsIncurred | 14,256us-gaap_RealEstateInventoryCapitalizedInterestCostsIncurred | |||||
| Interest expensed | (3,154)us-gaap_InterestExpense | (2,713)us-gaap_InterestExpense | |||||
| Interest amortized to cost of home and land closings | (9,345)us-gaap_RealEstateInventoryCapitalizedInterestCostsCostOfSales | (5,834)us-gaap_RealEstateInventoryCapitalizedInterestCostsCostOfSales | |||||
| Capitalized interest, end of period | 56,843us-gaap_RealEstateInventoryCapitalizedInterestCosts | [1] | 38,701us-gaap_RealEstateInventoryCapitalizedInterestCosts | [1] | |||
| Equity Method Land Ventures [Member] | |||||||
| Summary of capitalized interest | |||||||
| Capitalized interest, beginning of period | 
490us-gaap_RealEstateInventoryCapitalizedInterestCosts / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = mth_EquityMethodLandVenturesMember  | 
      ||||||
| Capitalized interest, end of period | 
$ 490us-gaap_RealEstateInventoryCapitalizedInterestCosts / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = mth_EquityMethodLandVenturesMember  | 
        
$ 490us-gaap_RealEstateInventoryCapitalizedInterestCosts / us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis = mth_EquityMethodLandVenturesMember  | 
      |||||
          
  | 
      |||||||
| X | ||||||||||
| 
             
- Definition 
          Amount of the cost of borrowed funds accounted for as interest expense. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
  | 
        
| X | ||||||||||
| 
             
- Definition 
          Carrying amount as of the balance sheet date of interest costs that were capitalized to properties under development during the land development and construction period of a project, and which are included in inventory. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
  | 
        
| X | ||||||||||
| 
             
- Definition 
          The amount of interest costs that had been capitalized to inventory which were charged to cost of sales during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
  | 
        
| X | ||||||||||
| 
             
- Definition 
          The amount of interest capitalized to an operative builder's inventory during the period. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
  | 
        
| X | ||||||||||
| 
             
- Details 
          
  | 
        
| X | ||||||||||
| 
             
- Details 
          
  |