Segments and Major Customers (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Financial information of business segments
Revenues	$ 58,297	$ 56,458	$ 106,681	$ 102,884
Segment operating expenses	40,134	40,699	80,817	82,064
Segment reconciling items	(55,209)	(35,746)	(94,319)	(84,420)
Operating income (loss)	(37,046)	(19,987)	(68,455)	(63,600)
Interest and other income (expense), net	4,438	3,615	9,580	8,310
Income (Loss) before income taxes	(32,608)	(16,372)	(58,875)	(55,290)
MID Segment
Financial information of business segments
Revenues	45,452	34,976	79,942	68,965
Segment operating expenses	25,440	22,597	49,419	45,546
Segment Operating Income (Loss)	20,012	12,379	30,523	23,419
RSD Segment
Financial information of business segments
Revenues	12,845	21,482	26,739	31,478
Segment operating expenses	12,690	14,893	26,911	27,678
Segment Operating Income (Loss)	155	6,589	(172)	3,800
Other
Financial information of business segments
Revenues	0	0	0	2,441
Segment operating expenses	2,004	3,209	4,487	8,840
Segment Operating Income (Loss)	(2,004)	(3,209)	(4,487)	(6,399)
Operating Segments [Member]
Financial information of business segments
Segment Operating Income (Loss)	$ 18,163	$ 15,759	$ 25,864	$ 20,820

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Amount of income (loss) from continuing operations, including income (loss) from equity method investments, before deduction of income tax expense (benefit), and income (loss) attributable to noncontrolling interest.

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