Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Current assets:
Cash and cash equivalents	$ 3,473	$ 20,821
Trade, less allowances of $334 and $470, respectively	66,239	59,385
Other	7,177	3,430
Prepaid expenses and other	15,490	15,426
Deferred income taxes	3,155	2,738
Total current assets	95,534	101,800
Property and equipment:
Revenue equipment	484,350	468,966
Buildings and land	39,664	30,602
Office equipment and other	27,122	24,406
Less accumulated depreciation	(156,660)	(155,774)
Net property and equipment	394,476	368,200
Other assets	613	579
	490,623	470,579
Current liabilities:
Accounts payable	16,081	17,912
Insurance and claims accruals	13,838	13,042
Accrued liabilities	16,981	15,431
Total current liabilities	46,900	46,385
Long-term debt, less current maturities	2,726
Deferred income taxes	109,074	103,835
Total liabilities	158,700	150,220
Stockholders’ equity:
Preferred stock, $.01 par value per share; 2,000,000 shares authorized; no shares issued and outstanding
Common stock, $.01 par value per share; 48,000,000 shares authorized; 22,109,619 shares at December 31, 2012, and 21,984,597 shares at December 31, 2011, issued and outstanding	221	220
Additional paid-in capital	82,679	80,078
Retained earnings	246,460	237,872
Total Marten Transport, Ltd. stockholders’ equity	329,360	318,170
Noncontrolling interest	2,563	2,189
Total stockholders’ equity	331,923	320,359
	$ 490,623	$ 470,579