Consolidated Condensed Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
OPERATING REVENUE	$ 167,103	$ 163,606	$ 492,990	$ 472,044
OPERATING EXPENSES (INCOME):
Salaries, wages and benefits	43,310	42,352	127,780	120,021
Purchased transportation	30,136	32,428	92,449	92,021
Fuel and fuel taxes	42,547	43,020	123,466	121,659
Supplies and maintenance	10,296	10,581	29,827	29,958
Depreciation	16,248	15,537	48,155	45,114
Operating taxes and licenses	1,811	1,694	5,406	4,893
Insurance and claims	5,741	4,809	17,360	15,816
Communications and utilities	1,305	1,265	3,850	3,637
Gain on disposition of revenue equipment	(1,472)	(1,349)	(5,124)	(4,053)
Other	3,528	3,429	10,509	10,336
Total operating expenses	153,450	153,766	453,678	439,402
OPERATING INCOME	13,653	9,840	39,312	32,642
OTHER	(130)	(6)	(298)	(40)
INCOME BEFORE INCOME TAXES	13,783	9,846	39,610	32,682
Less: Income before income taxes attributable to noncontrolling interest		61	84	467
INCOME BEFORE INCOME TAXES
ATTRIBUTABLE TO MARTEN TRANSPORT, LTD.	13,783	9,785	39,526	32,215
PROVISION FOR INCOME TAXES	5,806	3,267	16,680	12,667
NET INCOME	$ 7,977	$ 6,518	$ 22,846	$ 19,548
BASIC EARNINGS PER COMMON SHARE (in Dollars per share)	$ 0.24	$ 0.20	$ 0.69	$ 0.59
DILUTED EARNINGS PER COMMON SHARE (in Dollars per share)	$ 0.24	$ 0.20	$ 0.68	$ 0.59
DIVIDENDS PAID PER COMMON SHARE (in Dollars per share)	$ 0.025	$ 0.017	$ 0.058	$ 0.047