Commitments and Contingencies

12 Months Ended

Dec. 31, 2016

Commitments and Contingencies Disclosure [Abstract]

We are a party to ordinary, routine litigation and administrative proceedings incidental to our business. In the opinion of management, our potential exposure under pending legal proceedings is adequately provided for in the accompanying consolidated financial statements.

As part of a previous acquisition in 2013, we entered into an agreement with certain stockholders of the selling company ("Sellers"), which contained contingent consideration provisions. The contingent consideration included various earn-out targets tied to certain operational metrics of the acquired company as well as consolidated operational performance over the period of 2014 through 2017. The total potential earn-out is $20.0 million with maximum amounts payable each year as follows:



	(in thousands)
2014	$	6,000
2015	6,000
2016-2017	8,000
	$	20,000

Per the terms of the contingent consideration agreement, the Sellers will be entitled to any unearned earn-out amounts for 2014, 2015, and 2016 if the maximum earn-out target is achieved in the 2017 earn-out period, but in no event will the earn-out exceed $20.0 million in the aggregate for all earn-out periods. Contingent consideration of $0.0 million was paid in 2016 related to the 2015 earn-out requirements and $1.8 million was paid in 2015 related to 2014 earn-out requirements. At December 31, 2016, the Company estimated the potential earn-out liability was $0.0 million, based on operational targets to be achieved and actual results for 2016. At December 31, 2015, the Company estimated the potential earn-out liability was $12.2 million, of which $0.0 million was included in other current liabilities and $12.2 million was included in other long-term liabilities.

The total estimated purchase commitments for tractors, net of tractor sale commitments, and trailer equipment, at December 31, 2016, was $84.6 million.