Note 4 - Balance Sheet Components - Other Long-term Assets (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Deferred compensation plan assets	$ 39,456	$ 38,858
Operating lease right-of-use ("ROU") assets	3,909	2,863
Prepaid expense	2,515	2,687
Other	1,396	1,544
Total	$ 47,276	$ 45,952

Carrying amount as of the balance sheet date of assets held under deferred compensation agreements.

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- Definition

Amount of lessee's right to use underlying asset under operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121603541&loc=SL77918627-209977

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- Definition

Amount of other miscellaneous assets expected to be realized or consumed after one year or normal operating cycle, if longer.

+ References

No definition available.

+ Details

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- Definition

Amount of noncurrent assets classified as other.

+ References

+ Details

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- Definition

Carrying amount as of the balance sheet date of amounts paid in advance which will be charged against earnings in periods after one year or beyond the operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.17)
-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 4
-Subparagraph (g)
-URI http://asc.fasb.org/extlink&oid=121566466&loc=d3e6812-107765

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