Note 5 - Acquisitions - Acquisition Details (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Goodwill	$ 56,547	$ 309,227
Acquisitions 2020 [Member]
Current assets	36,281
Non-current assets	7,277
Current liabilities	(21,491)
Non-current liabilities	(1,350)
Deferred tax liabilities	(2,035)
Redeemable non-controlling interest	(21,293)
Business acquisition total	(2,611)
Cash consideration, net of cash acquired	(98,559)
Acquisition date fair value of contingent consideration	(13,259)
Total purchase consideration	(111,818)
Acquired intangible assets	57,882
Goodwill	$ 56,547
Acquisition 2019 [Member]
Current assets		34,454
Non-current assets		8,175
Current liabilities		(29,059)
Non-current liabilities		(1,574)
Deferred tax liabilities		(6,328)
Redeemable non-controlling interest		(9,874)
Business acquisition total		(4,206)
Cash consideration, net of cash acquired		(73,183)
Acquisition date fair value of contingent consideration		(10,611)
Total purchase consideration		(83,794)
Goodwill		58,381
Acquisition 2019 [Member] \| Order or Production Backlog [Member]
Acquired intangible assets		4,240
Acquisition 2019 [Member] \| Customer Relationships [Member]
Acquired intangible assets		13,168
Acquisition 2019 [Member] \| Trademarks and Trade Names [Member]
Acquired intangible assets		567
Acquisition 2019 [Member] \| Management Contracts and Other [Member]
Acquired intangible assets		$ 11,644

This element represents the fair value of the noncontrolling interest in the acquiree at the acquisition date.

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Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

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Amount of assets that are expected to be realized or consumed within one year or the normal operating cycle, if longer, acquired at the acquisition date.

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Amount of liabilities due within one year or within the normal operating cycle, if longer, assumed at the acquisition date.

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Amount of deferred tax liability attributable to taxable temporary differences assumed at the acquisition date.

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Amount of intangible assets, excluding goodwill, acquired at the acquisition date.

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The amount of identifiable intangible assets recognized as of the acquisition date.

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Amount recognized as of the acquisition date for the identifiable assets acquired in excess of (less than) the aggregate liabilities assumed.

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Amount of assets expected to be realized or consumed after one year or the normal operating cycle, if longer, acquired at the acquisition date.

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Fair value of contingent consideration in a business combination that is classified in shareholders' equity.

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Amount of increase in asset representing future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized resulting from a business combination.

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The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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