11. Leases

The Company incurred rent expense of $37.6 million, $51.9 million and $47.4 million for the years ended December 31, 2015, 2014 and 2013, 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, 2015 are as follows:

Year ending December 31,
2016	$	10,522
2017		4,969
2018		4,053
2019		3,229
2020		2,734
Thereafter		4,655
Total	$	30,162