We lease various office facilities, equipment and vehicles under operating lease arrangements, some of which contain rent escalation clauses. Most of the leases contain purchase and/or renewal options at fair market and fair rental value, respectively. Rental expense relating to all operating leases was $15.0 million, $13.6 million and $13.4 million in 2016, 2015 and 2014, respectively. At December 31, 2016, future minimum rental payments under noncancelable operating leases are as follows:



	Operating Leases
	(in thousands)
2017	$	14,888
2018	13,132
2019	9,561
2020	7,008
2021	4,506
Thereafter	5,155
Total minimum lease payments	$	54,250