Leases

We lease office space and equipment under operating lease agreements with varying terms. Certain leases require us to pay property taxes, insurance and routine maintenance and include renewal options and escalation clauses. Rent expense was $53 million, $46 million and $45 million in 2018, 2017 and 2016, respectively. Future minimum lease payments under non-cancelable operating leases at December 31, 2018 were as follows:



Years ending December 31,
2019	$	48,182
2020	41,366
2021	34,665
2022	26,616
2023	17,988
Thereafter	62,668
Total minimum lease payments	$	231,485