Consolidated Condensed Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
OPERATING REVENUE	$ 156,964	$ 151,135	$ 308,438	$ 288,991
OPERATING EXPENSES (INCOME):
Salaries, wages and benefits	39,398	36,413	77,669	70,512
Purchased transportation	29,734	29,991	59,593	58,008
Fuel and fuel taxes	39,515	39,915	78,639	75,255
Supplies and maintenance	9,841	9,774	19,377	19,436
Depreciation	15,042	14,084	29,577	27,600
Operating taxes and licenses	1,617	1,516	3,199	2,933
Insurance and claims	5,185	4,412	11,007	8,713
Communications and utilities	1,161	1,106	2,372	2,228
Gain on disposition of revenue equipment	(1,179)	(967)	(2,704)	(1,735)
Other	3,367	3,532	6,907	7,073
Total operating expenses	143,681	139,776	285,636	270,023
OPERATING INCOME	13,283	11,359	22,802	18,968
NET INTEREST (INCOME) EXPENSE	(13)	(7)	(34)	12
INCOME BEFORE INCOME TAXES	13,296	11,366	22,836	18,956
Less: Income before income taxes attributable to noncontrolling interest	245	253	406	390
INCOME BEFORE INCOME TAXES ATTRIBUTABLE TO MARTEN TRANSPORT, LTD.	13,051	11,113	22,430	18,566
PROVISION FOR INCOME TAXES	5,467	4,919	9,400	8,277
NET INCOME	$ 7,584	$ 6,194	$ 13,030	$ 10,289
BASIC EARNINGS PER COMMON SHARE (in Dollars per share)	$ 0.34	$ 0.28	$ 0.59	$ 0.47
DILUTED EARNINGS PER COMMON SHARE (in Dollars per share)	$ 0.34	$ 0.28	$ 0.59	$ 0.47
DIVIDENDS PAID PER COMMON SHARE (in Dollars per share)	$ 0.025	$ 0.02	$ 0.045	$ 0.04