Consolidated Condensed Statements of Operations (Unaudited) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
OPERATING REVENUE	$ 171,550	$ 167,103	$ 499,382	$ 492,990
OPERATING EXPENSES (INCOME):
Salaries, wages and benefits	46,435	43,310	134,834	127,780
Purchased transportation	32,914	30,136	91,783	92,449
Fuel and fuel taxes	39,398	42,547	119,718	123,466
Supplies and maintenance	10,273	10,296	31,059	29,827
Depreciation	17,253	16,248	50,489	48,155
Operating taxes and licenses	1,837	1,811	5,278	5,406
Insurance and claims	6,205	5,741	18,993	17,360
Communications and utilities	1,507	1,305	4,251	3,850
Gain on disposition of revenue equipment	(1,419)	(1,472)	(3,360)	(5,124)
Other	4,105	3,528	11,723	10,509
Total operating expenses	158,508	153,450	464,768	453,678
OPERATING INCOME	13,042	13,653	34,614	39,312
OTHER	(226)	(130)	(936)	(298)
INCOME BEFORE INCOME TAXES	13,268	13,783	35,550	39,610
Less: Income before income taxes attributable to noncontrolling interest				84
INCOME BEFORE INCOME TAXES ATTRIBUTABLE TO MARTEN TRANSPORT, LTD.	13,268	13,783	35,550	39,526
PROVISION FOR INCOME TAXES	5,616	5,806	14,685	16,680
NET INCOME	$ 7,652	$ 7,977	$ 20,865	$ 22,846
BASIC EARNINGS PER COMMON SHARE (in Dollars per share)	$ 0.23	$ 0.24	$ 0.63	$ 0.69
DILUTED EARNINGS PER COMMON SHARE (in Dollars per share)	$ 0.23	$ 0.24	$ 0.62	$ 0.68
DIVIDENDS DECLARED PER COMMON SHARE (in Dollars per share)	$ 0.025	$ 0.025	$ 0.075	$ 0.058