Other Non-Operating Income (Expense), Net (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018		Dec. 31, 2017		Dec. 31, 2016	[1]
Other Non-Operating Income (Expense), Net [Abstract]
Interest and dividend income			$ 80		$ 91	[1]	$ 153
Equity income (loss) from joint ventures			(768)	[2]	(602)	[1],[2]	2,029
Gain (loss) on foreign exchange			(120)		950	[1]	(276)
Postretirement plan net periodic benefit credit (cost)			262		653	[1]	(722)
Other non-operating income, net			135		158	[1]	153
Total other non-operating income (expense), net			(411)		1,250	[1]	$ 1,337
Orange Electronic Co., Ltd [Member]
Asset Impairment Charges [Abstract]
Impairment charges	$ 1,700	$ 1,800	$ 1,700		$ 1,800

[1] Net periodic benefit credit (cost) has been reclassified from selling, general and administrative expenses to other non-operating income (expense), net on our consolidated statement of operations upon adoption of ASU 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost, see Note 1, "Summary of Significant Accounting Policies" for additional information.

[2] Year ended December 31, 2018 and 2017 includes a noncash impairment charge of approximately $1.7 million and $1.8 million, respectively, related to our minority interest investment in Orange Electronic Co., Ltd. (See Note 10 for additional information).