| Operating and Reporting Segments Operating and Reporting Segments (Details 2) (Details) (USD $) | 12 Months Ended | ||
|---|---|---|---|
| Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | |
| Segment Reporting Information [Line Items] | |||
| Land closing revenue | $ 27,252,000us-gaap_LandSales | $ 31,270,000us-gaap_LandSales | $ 9,314,000us-gaap_LandSales | 
| West [Member] | |||
| Segment Reporting Information [Line Items] | |||
| Land closing revenue | 11,155,000us-gaap_LandSales / us-gaap_StatementGeographicalAxis = mth_WestMember | 11,616,000us-gaap_LandSales / us-gaap_StatementGeographicalAxis = mth_WestMember | 6,488,000us-gaap_LandSales / us-gaap_StatementGeographicalAxis = mth_WestMember | 
| Central [Member] | |||
| Segment Reporting Information [Line Items] | |||
| Land closing revenue | 8,603,000us-gaap_LandSales / us-gaap_StatementGeographicalAxis = mth_CentralMember | 16,184,000us-gaap_LandSales / us-gaap_StatementGeographicalAxis = mth_CentralMember | 2,036,000us-gaap_LandSales / us-gaap_StatementGeographicalAxis = mth_CentralMember | 
| East [Member] | |||
| Segment Reporting Information [Line Items] | |||
| Land closing revenue | $ 7,494,000us-gaap_LandSales / us-gaap_StatementGeographicalAxis = mth_EastMember | $ 3,470,000us-gaap_LandSales / us-gaap_StatementGeographicalAxis = mth_EastMember | $ 790,000us-gaap_LandSales / us-gaap_StatementGeographicalAxis = mth_EastMember | 
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