Consolidated Statements of Operations - USD ($) |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2017 |
Dec. 31, 2016 |
Dec. 31, 2015 |
|
| Income Statement [Abstract] | |||
| Revenue | $ 1,943,086,192 | $ 1,716,152,159 | $ 1,512,298,686 |
| Costs and expenses: | |||
| Transportation costs | 1,604,045,563 | 1,397,577,664 | 1,222,035,371 |
| Selling, general and administrative expenses | 287,227,430 | 270,826,387 | 243,214,264 |
| Depreciation and amortization | 32,727,727 | 32,137,592 | 24,142,527 |
| Income from operations | 19,085,472 | 15,610,516 | 22,906,524 |
| Interest income | 31,883 | 0 | 23,909 |
| Interest expense | (14,767,621) | (14,226,796) | (11,276,207) |
| Other expense | 0 | 0 | (126,295) |
| Interest and other expense | (14,735,738) | (14,226,796) | (11,378,593) |
| Income before provision for income taxes | 4,349,734 | 1,383,720 | 11,527,931 |
| Income tax benefit (expense) | 8,273,495 | 205,958 | (3,682,257) |
| Net income | $ 12,623,229 | $ 1,589,678 | $ 7,845,674 |
| Earnings per common share: | |||
| Basic (USD per share) | $ 0.46 | $ 0.06 | $ 0.29 |
| Diluted (USD per share) | $ 0.45 | $ 0.05 | $ 0.28 |