Operating Leases

12 Months Ended

Dec. 31, 2018

Operating lease expense incurred primarily for manufacturing and office space, machinery, and equipment was $31.7 million, $38.6 million, and $40.3 million in 2018, 2017, and 2016, respectively.

Minimum annual lease payments for noncancelable operating leases in effect at December 31, 2018 are as follows (in thousands):



2019	$	19,877
2020	17,531
2021	14,776
2022	12,317
2023	7,654
Thereafter	28,771
	$	100,926

Certain of our operating leases include step rent provisions and rent escalations. We include these step rent provisions and rent escalations in our minimum lease payments obligations and recognize them as a component of rental expense on a straight-line basis over the minimum lease term.