15. Commitments

The Company has entered into leases covering principally office, research and warehouse space, office equipment and vehicles. Future minimum rental payments required under all operating leases that have remaining non-cancelable lease terms in excess of one year are $8.2 million in 2017, $6.0 million in 2018, $4.0 million in 2019, $2.4 million in 2020, $2.2 million in 2021, and $18.5 million thereafter. Total rental expense on all operating leases was $8.0 million, $8.9 million, and $7.9 million for the years ended December 31, 2016, 2015, and 2014, respectively.

The Company has unconditional purchase obligations for raw materials and information systems and services under long-term supply contracts.

Future minimum purchase requirements under the terms of the aforementioned contracts are as follows:


	Due in
	2017		2018		2019		2020		2021		Thereafter
Raw and other materials	$	19,190	$	21,049	$	781	$	781	$	781	$	—
Information systems and services		2,185		2,250		710		65		—		—
Total contractual cash obligations	$	21,375	$	23,299	$	1,491	$	846	$	781	$	—

Total payments made for purchases under these supply contracts were as follows:


	December 31
	2016		2015		2014
Raw and other materials	$	21,178	$	27,832	$	38,096
Information systems and services		1,384		1,871		2,163
Total payments	$	22,562	$	29,703	$	40,259