Operating Leases (Tables)

12 Months Ended

Dec. 31, 2017

Leases [Abstract]

Summary of Minimum Annual Lease Payments for Noncancelable Operating Leases

Minimum annual lease payments for noncancelable operating leases in effect at December 31, 2017 are as follows (in thousands):

2018	$	22,440
2019	18,006
2020	13,787
2021	11,001
2022	8,561
Thereafter	23,494
	$	97,289