Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 32
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8933-108599

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 280
-SubTopic 10
-Section 50
-Paragraph 22
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=115929826&loc=d3e8736-108599

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(1))
-URI http://asc.fasb.org/extlink&oid=116634182&loc=SL114868664-224227

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

Geographic / Customer Concentration - Schedule of Revenue by Major Customers by Reporting Segments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Past Patent Royalties \| Blackberry
Revenue from External Customer [Line Items]
Revenues			$ 70.7
Past Patent Royalties \| Huawei
Revenue from External Customer [Line Items]
Revenues			$ 8.4
Customer Concentration Risk \| Revenue \| Apple
Revenue from External Customer [Line Items]
Entity-wide revenues, major customer, percentage	35.00%	36.00%	21.00%
Customer Concentration Risk \| Revenue \| Samsung Electronics, Ltd.
Revenue from External Customer [Line Items]
Entity-wide revenues, major customer, percentage	25.00%	25.00%	13.00%
Customer Concentration Risk \| Revenue \| LG
Revenue from External Customer [Line Items]
Entity-wide revenues, major customer, percentage	10.00%	10.00%	10.00%
Customer Concentration Risk \| Revenue \| Blackberry
Revenue from External Customer [Line Items]
Entity-wide revenues, major customer, percentage	0.00%	0.00%	13.00%
Customer Concentration Risk \| Revenue \| Huawei
Revenue from External Customer [Line Items]
Entity-wide revenues, major customer, percentage	0.00%	0.00%	14.00%