Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue Equipment [Member]
Operating expenses (income):
Gain on disposition of revenue equipment	$ (5,584)	$ (4,387)	$ (5,972)
Facility [Member]
Operating expenses (income):
Gain on disposition of revenue equipment	(4,104)
Operating revenue	664,994	$ 672,929	$ 659,214
Salaries, wages and benefits	209,455	183,464	171,314
Purchased transportation	118,030	123,017	123,436
Fuel and fuel taxes	104,582	153,931	163,270
Supplies and maintenance	43,319	41,490	40,582
Depreciation	75,323	68,243	64,476
Operating taxes and licenses	8,914	7,140	7,110
Insurance and claims	29,252	27,240	23,681
Communications and utilities	5,886	5,798	5,212
Other	18,858	15,987	14,110
	603,931	621,923	607,219
Operating income	61,063	51,006	51,995
Other	372	(667)	(392)
Income before income taxes	$ 60,691	$ 51,673	52,387
Less: Income before income taxes attributable to noncontrolling interest			84
Income before income taxes attributable to Marten Transport, Ltd.	$ 60,691	$ 51,673	52,303
Provision for income taxes	24,946	21,839	22,156
Net income	$ 35,745	$ 29,834	$ 30,147
Basic earnings per common share (in dollars per share)	$ 1.07	$ 0.89	$ 0.91
Diluted earnings per common share (in dollars per share)	1.06	0.89	0.90
Dividends declared per common share (in dollars per share)	$ 0.10	$ 0.10	$ 0.083