Geographic Information (Tables)

12 Months Ended

Dec. 31, 2017

Segment Reporting [Abstract]

Revenues and Long-Lived Assets by Geographic Area Table

	Year Ended December 31,
	2017		2016		2015
	(In Thousands)
Revenues from external customers:
U.S.	$	265,311	$	270,828	$	411,028
Latin America	23,493		32,673		36,843
Canada	3,678		2,666		4,282
Other	3,084		5,196		5,488
Total	$	295,566	$	311,363	$	457,641
Identifiable assets:
U.S.	$	691,588	$	733,077	$	907,028
Latin America	45,170		48,303		54,362
Canada	4,278		2,895		2,307
Other	1,896		1,865		2,930
Total identifiable assets	$	742,932	$	786,140	$	966,627