Leases (Tables)

12 Months Ended

Dec. 31, 2017

Leases [Abstract]

Operating Leases of Lessee Disclosure

Minimum payments due in future years under these agreements in effect at December 31, 2017 are as follows:

	Operating
	Leases		Royalties
	(In thousands)
2018	$	5,936	$	3,582
2019	4,655		5,926
2020	2,260		6,953
2021	1,985		7,216
2022	2,024		7,003
Thereafter	8,292		34,371
	$	25,152	$	65,051