Consolidated statements of comprehensive income (loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net (loss) income	$ (3,120)	$ (1,080)	$ 9,899	$ 23,604
Other comprehensive income (loss), net of tax:
Foreign currency translation (net of tax effect of $0, $0, $0 and $0, respectively)	1,605	(4,267)	1,942	(3,012)
Retirement related benefit plans (net of tax effect of $0 $(17), $0 and $(7), respectively)	16	118	244	106
Total other comprehensive income (loss)	1,621	(4,149)	2,186	(2,906)
Comprehensive (loss) income	$ (1,499)	$ (5,229)	$ 12,085	$ 20,698