INCOME TAXES (Detail Texuals) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012
Income Tax Disclosure [Abstract]
Current income tax expense benefit adjustment of federal and other tax	$ 1,361

Component of income tax expense (benefit) attributable to an adjustment of federal domestic activity deductions, as well as federal research and development and other tax credits.

No definition available.

Name:	mlr_CurrentIncomeTaxExpenseBenefitAdjustmentOfFederalAndOtherTax
Namespace Prefix:	mlr_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration