Commitments and Contingencies Other (Details) - Exar Corporation [Member] $ in Millions  | 
3 Months Ended | 
|---|---|
| 
 Mar. 31, 2018  
USD ($) 
 | |
| Loss Contingencies [Line Items] | |
| Release of indemnification asset | $ 0.9 | 
| Business Combination, Indemnification Assets, Range of Outcomes, Value, High | 13.6 | 
| Indemnification Agreement [Member] | |
| Loss Contingencies [Line Items] | |
| Business Combination, Indemnification Assets, Range of Outcomes, Value, High | 136.0 | 
| Representations and Warranties [Member] | |
| Loss Contingencies [Line Items] | |
| Business Combination, Indemnification Assets, Range of Outcomes, Value, High | 34.0 | 
| Intellectual Property [Member] | |
| Loss Contingencies [Line Items] | |
| Business Combination, Indemnification Assets, Range of Outcomes, Value, High | $ 34.0 | 
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- Definition Release of indemnification asset No definition available. 
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- Definition For indemnification assets recognized in connection with a business combination, this element represents an estimate of the high-end of the potential range (undiscounted) of the indemnification benefit which may be realized. Reference 1: http://www.xbrl.org/2003/role/presentationRef 
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- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. No definition available. 
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