Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Fair value portion of currency on hand as well as demand deposits with banks or financial institutions. Includes other kinds of accounts that have the general characteristics of demand deposits. Also includes short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. This element is for unclassified presentations; for classified presentations there is a separate and distinct element.

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Note 8 - Fair Value Measurements - Summary of Fair Value Measurements by Level (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Restricted cash and cash equivalents	$ 5,254	$ 11,106	$ 10,651
Available-for-sale securities	321,717	286,034
Fair Value, Measurements, Recurring [Member]
Cash and cash equivalents	26,335	38,208
Restricted cash and cash equivalents	5,254	11,106
Total financial assets	353,306	335,348
Fair Value, Measurements, Recurring [Member] \| Equity Securities [Member]
Available-for-sale securities	138,013	116,168
Fair Value, Measurements, Recurring [Member] \| Corporate Debt Securities [Member]
Available-for-sale securities	71,100	71,143
Fair Value, Measurements, Recurring [Member] \| Asset-backed Securities [Member]
Available-for-sale securities	56,168	60,910
Fair Value, Measurements, Recurring [Member] \| US Treasury Securities [Member]
Available-for-sale securities	25,181	21,033
Fair Value, Measurements, Recurring [Member] \| US States and Political Subdivisions Debt Securities [Member]
Available-for-sale securities	31,255	16,780
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	26,335	38,208
Restricted cash and cash equivalents	5,254	11,106
Total financial assets	237,106	219,198
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Equity Securities [Member]
Available-for-sale securities	138,013	116,168
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Corporate Debt Securities [Member]
Available-for-sale securities	42,323	32,683
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Asset-backed Securities [Member]
Available-for-sale securities
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| US Treasury Securities [Member]
Available-for-sale securities	25,181	21,033
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| US States and Political Subdivisions Debt Securities [Member]
Available-for-sale securities
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]
Cash and cash equivalents
Restricted cash and cash equivalents
Total financial assets	116,200	116,150
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Equity Securities [Member]
Available-for-sale securities
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Corporate Debt Securities [Member]
Available-for-sale securities	28,777	38,460
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Asset-backed Securities [Member]
Available-for-sale securities	56,168	60,910
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| US Treasury Securities [Member]
Available-for-sale securities
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| US States and Political Subdivisions Debt Securities [Member]
Available-for-sale securities	$ 31,255	$ 16,780