21. Leases

The Company leases various property, plant and equipment. Terms of the leases vary, but generally require the Company to pay property taxes, insurance premiums, and maintenance costs associated with the leased property. Rental expense attributed to operating leases was $20.2 million, $23.1 million and $16.8 million in 2017, 2016 and 2015, respectively.

Future minimum rental obligations under non-cancelable operating leases as of December 31, 2017 are payable as follows:

(in millions)
2018	$	18.5
2019		15.7
2020		14.8
2021		13.9
2022		12.7
Thereafter		20.7
Total	$	96.3