Consolidated Condensed Balance Sheets (Unaudited) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 635	$ 3,473
Receivables:
Trade, net	68,588	66,239
Other	2,863	7,177
Prepaid expenses and other	13,836	15,490
Deferred income taxes	3,364	3,155
Total current assets	89,286	95,534
Property and equipment:
Revenue equipment, buildings and land, office equipment and other	588,038	551,136
Accumulated depreciation	(160,153)	(156,660)
Net property and equipment	427,885	394,476
Other assets	3,359	613
TOTAL ASSETS	520,530	490,623
Current liabilities:
Accounts payable and accrued liabilities	42,606	33,062
Insurance and claims accruals	14,029	13,838
Total current liabilities	56,635	46,900
Long-term debt, less current maturities	7,387	2,726
Deferred income taxes	112,413	109,074
Total liabilities	176,435	158,700
Marten Transport, Ltd. 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; 33,220,969 shares at June 30, 2013, and 33,164,428 shares at December 31, 2012, issued and outstanding	332	332
Additional paid-in capital	83,652	82,679
Retained earnings	260,111	246,349
Total Marten Transport, Ltd. stockholders’ equity	344,095	329,360
Noncontrolling interest		2,563
Total stockholders’ equity	344,095	331,923
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 520,530	$ 490,623