Annual report pursuant to Section 13 and 15(d)

Stock Based Compensation (Details 4)

v2.4.1.9
Stock Based Compensation (Details 4) (USD $)
In Thousands, except Share data, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Summary of stock based compensation agreements    
Unrecognized stock-based compensation cost $ 20,577us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized $ 17,385us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
Weighted average years expense recognition period 2 years 1 month 10 days 2 years 2 months 5 days
Total equity awards outstanding 1,255,714mth_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesOutstanding 1,317,710mth_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesOutstanding