Note 12 - Income Taxes (Details) - Deferred Tax Assets and Liabilities (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Current deferred tax asset:
Allowance for doubtful accounts receivable	$ 2,138	$ 1,802
Accrued risk reserves	964	857
Accrued expenses	3,635	3,593
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Current deferred tax liability:
Unrealized gains on marketable securities	(39,958)	(29,120)
Other	(2,284)us-gaap_DeferredTaxLiabilitiesOther	(1,922)us-gaap_DeferredTaxLiabilitiesOther
	(42,242)	(31,042)
Net current deferred tax liability	(35,505)	(24,790)
Noncurrent deferred tax asset:
Unrealized gains on marketable securities	(183)	593
Financial reporting depreciation in excess of tax depreciation	7,191	5,872
Deferred gain on sale of assets (net)	(3,135)	(3,135)
Tax basis intangible asset in excess of financial reporting basis	(409)	127
Stock-based compensation	2,879	2,214
Long-term investments	(2,445)us-gaap_DeferredTaxAssetsInvestments	(2,276)us-gaap_DeferredTaxAssetsInvestments
Obligation to provide future services	1,532us-gaap_DeferredTaxAssetsOther	1,439us-gaap_DeferredTaxAssetsOther
Accrued risk reserves, less current portion	2,295	3,040
Accrued expenses	2,910	2,502
Deferred revenue	6,197us-gaap_DeferredTaxAssetsDeferredIncome	6,096us-gaap_DeferredTaxAssetsDeferredIncome
Net noncurrent deferred tax asset	18,700	18,164
Nonrefundable Entrance Fees [Member]
Noncurrent deferred tax asset:
Entrance fees	129	45
Refundable Entrance Fees [Member]
Noncurrent deferred tax asset:
Entrance fees	$ 1,739	$ 1,647

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