Note 13 - Termination of Deferred Compensation Plan	12 Months Ended
Dec. 31, 2021
Notes to Financial Statements
Compensation Related Costs, General [Text Block]	13. Termination of Deferred Compensation Plan In August 2010, our Board of Directors approved and adopted the Marten Transport, Ltd. Deferred Compensation Plan. The deferred compensation plan was an unfunded, nonqualified deferred compensation plan designed to allow board elected officers and other select members of our management designated by our Compensation Committee to save for retirement on a tax-deferred basis. Under the terms of the plan, each participant was eligible to defer portions of their base pay, annual bonus, or receipt of common stock otherwise payable under a vested performance unit award. Each participant could have elected a fixed distribution date for the participant’s deferral account other than certain required performance unit award deferrals credited to the discretionary account, which were to be distributed after the later of the date of the participant’s termination of employment or the date the participant attains age 62. Upon termination of a participant’s employment with the company, the plan required a lump-sum distribution of the deferral account, excluding the required performance unit award deferrals, unless the participant had elected an installment distribution. Upon a participant’s death, the plan provided that a participant’s distributions accelerate and be paid in a lump sum to the participant’s beneficiary. We had the ability to terminate the plan and accelerate distributions to participants, but only to the extent and at the times permitted under Section 409A of the Internal Revenue Code of 1986, as amended. We had the ability to terminate the plan and accelerate distributions upon a change in control, which was not a payment event under the plan. In conjunction with the approval of the plan, our Board of Directors also adopted an amendment to the Marten Transport, Ltd. 2005 Stock Incentive Plan to allow for deferral of receipt of income from a performance unit award under the plan. Such deferral is also provided for within the Marten Transport, Ltd. 2015 Equity Incentive Plan. As of December 31, 2021, 102,737 shares of Company common stock with a value of $1.8 million were credited to account balances within the plan. These shares were required performance unit award deferrals of vested awards, and dividends earned on such shares. On May 5, 2020, our Compensation Committee and Board of Directors approved the termination of our deferred compensation plan. The termination was effective May 5, 2021. All shares of Company common stock within the plan will be distributed by May 5, 2022.

Note 13 - Termination of Deferred Compensation Plan

12 Months Ended

Dec. 31, 2021

13. Termination of Deferred Compensation Plan

In August 2010, our Board of Directors approved and adopted the Marten Transport, Ltd. Deferred Compensation Plan. The deferred compensation plan was an unfunded, nonqualified deferred compensation plan designed to allow board elected officers and other select members of our management designated by our Compensation Committee to save for retirement on a tax-deferred basis.

Under the terms of the plan, each participant was eligible to defer portions of their base pay, annual bonus, or receipt of common stock otherwise payable under a vested performance unit award. Each participant could have elected a fixed distribution date for the participant’s deferral account other than certain required performance unit award deferrals credited to the discretionary account, which were to be distributed after the later of the date of the participant’s termination of employment or the date the participant attains age 62. Upon termination of a participant’s employment with the company, the plan required a lump-sum distribution of the deferral account, excluding the required performance unit award deferrals, unless the participant had elected an installment distribution. Upon a participant’s death, the plan provided that a participant’s distributions accelerate and be paid in a lump sum to the participant’s beneficiary. We had the ability to terminate the plan and accelerate distributions to participants, but only to the extent and at the times permitted under Section 409A of the Internal Revenue Code of 1986, as amended. We had the ability to terminate the plan and accelerate distributions upon a change in control, which was not a payment event under the plan. In conjunction with the approval of the plan, our Board of Directors also adopted an amendment to the Marten Transport, Ltd. 2005 Stock Incentive Plan to allow for deferral of receipt of income from a performance unit award under the plan. Such deferral is also provided for within the Marten Transport, Ltd. 2015 Equity Incentive Plan. As of December 31, 2021, 102,737 shares of Company common stock with a value of $1.8 million were credited to account balances within the plan. These shares were required performance unit award deferrals of vested awards, and dividends earned on such shares.

On May 5, 2020, our Compensation Committee and Board of Directors approved the termination of our deferred compensation plan. The termination was effective May 5, 2021. All shares of Company common stock within the plan will be distributed by May 5, 2022.