Unaudited Quarterly Financial Data (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
Jun. 30, 2019	Dec. 31, 2019
Gain on disposal		$ 33,599
Control Devices [Member] \| Non-core Switches and Connector Product [Member]
Gain on disposal	$ 33,599

Amount of other income that is infrequent in occurrence or unusual in nature.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 20
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=114868883&loc=SL114871943-224233

Name:	us-gaap_OtherNonrecurringIncome
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration