Note 14 - Deferred Compensation Plan (Details Textual)	Dec. 31, 2015 shares
Deferred Compensation Plan Number Of Common Shares Credited To Account Balances	90,143

Deferred compensation plan number of common shares credited to account balances.

No definition available.

Name:	mrtn_DeferredCompensationPlanNumberOfCommonSharesCreditedToAccountBalances
Namespace Prefix:	mrtn_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant