XML 32 R31.htm IDEA: XBRL DOCUMENT v3.19.3

Note 5 - Related Party Transactions (Details Textual) - USD ($)	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Purchase of Fuel, Tires and Related Services [Member]
Related Party Transaction, Amounts of Transaction	$ 311,000	$ 233,000
Tire Purchases [Member]
Related Party Transaction, Amounts of Transaction	$ 1,200,000	$ 2,000,000.0

X

- Definition

Amount of transactions with related party during the financial reporting period.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39622-107864

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864

+ Details

Name:	us-gaap_RelatedPartyTransactionAmountsOfTransaction
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

X

- Details

Name:	us-gaap_NatureOfExpenseAxis=mrtn_PurchaseOfFuelTiresAndRelatedServicesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

X

- Details

Name:	us-gaap_NatureOfExpenseAxis=mrtn_TirePurchasesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: