12. Leases

The Company incurred rent expense of $25.3 million, $37.6 million and $51.9 million for the years ended December 31, 2016, 2015 and 2014, respectively. Rent expense is primarily related to short-term equipment rentals that are generally passed through to customers.

Future minimum rental payments required under operating leases having initial or remaining non-cancelable lease terms in excess of one year at December 31, 2016 are as follows:

Year ending December 31,
2017	$	5,707
2018		4,991
2019		4,524
2020		3,864
2021		2,822
Thereafter		9,145
Total	$	31,053