Guarantees	3 Months Ended
Mar. 31, 2012
Guarantees [Abstract]
Guarantees	NOTE 8. Guarantees As a recruiting tool and a benefit to our owner-operators, we are guaranteeing certain owner-operators' lease payments for tractors. The guarantees expire at various dates beginning in 2012 thru 2019. The potential maximum exposure under these lease guarantees was approximately $32.4 million and $24.0 million as of March 31, 2012 and December 31, 2011, respectively. The potential maximum exposure represents the amount of the remaining lease payments on all outstanding guaranteed leases as of March 31, 2012 and December 31, 2011. However, upon default, we have the option to purchase the tractors. We could then sell the tractors and use the proceeds to recover all or a portion of the amounts paid under the guarantees. Alternatively, we can contract with another owner-operator who would assume the lease. There were no material defaults during the periods ended March 31, 2012 and December 31, 2011 and no potential material defaults. We had a liability of approximately $0.7 million as of March 31, 2012 and $0.5 million as of December 31, 2011 for the guarantees representing the fair value of the guarantees based on a discounted cash-flow analysis which is included in non-current liabilities in our Consolidated Balance Sheets. We are amortizing the amounts over the remaining lives of the respective guarantees.

NOTE 8. Guarantees

As a recruiting tool and a benefit to our owner-operators, we are guaranteeing certain owner-operators' lease payments for tractors. The guarantees expire at various dates beginning in 2012 thru 2019.

The potential maximum exposure under these lease guarantees was approximately $32.4 million and $24.0 million as of March 31, 2012 and December 31, 2011, respectively. The potential maximum exposure represents the amount of the remaining lease payments on all outstanding guaranteed leases as of March 31, 2012 and December 31, 2011. However, upon default, we have the option to purchase the tractors. We could then sell the tractors and use the proceeds to recover all or a portion of the amounts paid under the guarantees. Alternatively, we can contract with another owner-operator who would assume the lease. There were no material defaults during the periods ended March 31, 2012 and December 31, 2011 and no potential material defaults.

We had a liability of approximately $0.7 million as of March 31, 2012 and $0.5 million as of December 31, 2011 for the guarantees representing the fair value of the guarantees based on a discounted cash-flow analysis which is included in non-current liabilities in our Consolidated Balance Sheets. We are amortizing the amounts over the remaining lives of the respective guarantees.