Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 27,115	$ 2,954	$ 13,049	$ (22,085)
Change in other postretirement benefit plans, net of tax	0	0	(681)	373
Foreign currency translation adjustment	2,437	1,320	(3,262)	2,828
Comprehensive income (loss)	$ 29,552	$ 4,274	$ 9,106	$ (18,884)