Consolidated Condensed Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
OPERATING REVENUE	$ 161,413	$ 156,964	$ 325,887	$ 308,438
OPERATING EXPENSES (INCOME):
Salaries, wages and benefits	42,345	39,398	84,470	77,669
Purchased transportation	28,129	29,734	62,313	59,593
Fuel and fuel taxes	40,596	39,515	80,919	78,639
Supplies and maintenance	9,998	9,841	19,531	19,377
Depreciation	16,219	15,042	31,907	29,577
Operating taxes and licenses	1,825	1,617	3,595	3,199
Insurance and claims	5,808	5,185	11,619	11,007
Communications and utilities	1,262	1,161	2,545	2,372
Gain on disposition of revenue equipment	(1,237)	(1,179)	(3,652)	(2,704)
Other	3,347	3,367	6,981	6,907
Total operating expenses	148,292	143,681	300,228	285,636
OPERATING INCOME	13,121	13,283	25,659	22,802
OTHER	(153)	(13)	(168)	(34)
INCOME BEFORE INCOME TAXES	13,274	13,296	25,827	22,836
Less: Income before income taxes attributable to noncontrolling interest		245	84	406
INCOME BEFORE INCOME TAXES
ATTRIBUTABLE TO MARTEN TRANSPORT, LTD.	13,274	13,051	25,743	22,430
PROVISION FOR INCOME TAXES	5,607	5,467	10,874	9,400
NET INCOME	$ 7,667	$ 7,584	$ 14,869	$ 13,030
BASIC EARNINGS PER COMMON SHARE (in Dollars per share)	$ 0.23	$ 0.23	$ 0.45	$ 0.39
DILUTED EARNINGS PER COMMON SHARE (in Dollars per share)	$ 0.23	$ 0.23	$ 0.45	$ 0.39
DIVIDENDS PAID PER COMMON SHARE (in Dollars per share)	$ 0.017	$ 0.017	$ 0.033	$ 0.03