Note 11 - Related Party Transactions (Details Textual) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2018 USD ($)	Jun. 30, 2018 USD ($)
Powersem [Member]
Revenue from Related Parties	$ 0.3	$ 0.4
Related Party Transaction, Purchases from Related Party	1.0	2.1
Accounts Receivable, Related Parties	0.1	0.1
Accounts Payable, Related Parties	0.3	0.3
EB Tech [Member]
Related Party Transaction, Amounts of Transaction	0.1	0.2
ATEC [Member]
Accounts Payable, Related Parties	0.7	0.7
Related Party Transaction, Amounts of Transaction	$ 2.8	$ 5.2
Powersem [Member]
Equity Method Investment, Ownership Percentage	45.00%	45.00%
EB Tech [Member]
Equity Method Investment, Ownership Percentage	20.00%	20.00%
ATEC [Member]
Equity Method Investment, Ownership Percentage	24.00%	24.00%

Amount for accounts payable to related parties.

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For an unclassified balance sheet, amount of receivables arising from transactions with related parties.

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The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

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Amount of transactions with related party during the financial reporting period.

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Purchases during the period (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

+ References

No definition available.

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Amount of revenue, fees and commissions earned from transactions between (a) a parent company and its subsidiaries; (b) subsidiaries of a common parent; (c) an entity and trusts for the benefit of employees, for example, but not limited to, pension and profit-sharing trusts that are managed by or under the trusteeship of the entity's management; (d) an entity and its principal, owners, management, or members of their immediate families; and (e) affiliates.

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 946
-SubTopic 220
-Section S99
-Paragraph 1
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