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 security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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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.

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Amount of cash and cash equivalents restricted as to withdrawal or usage. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, 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.

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Note 10 - Fair Value Measurements - Summary of Fair Value Measurements by Level (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017
Restricted cash and cash equivalents	$ 11,778		$ 16,713
Available-for-sale securities	162,756	$ 166,395
Corporate Debt Securities [Member]
Available-for-sale securities	66,291	65,461
Collateralized Mortgage Backed Securities [Member]
Available-for-sale securities	51,488	53,544
US States and Political Subdivisions Debt Securities [Member]
Available-for-sale securities	24,237	26,218
Fair Value, Measurements, Recurring [Member]
Cash and cash equivalents	54,962	59,118
Restricted cash and cash equivalents	11,778	8,303
Total financial assets	353,064	372,901
Fair Value, Measurements, Recurring [Member] \| Equity Securities [Member]
Available-for-sale securities	123,568	139,085
Fair Value, Measurements, Recurring [Member] \| Corporate Debt Securities [Member]
Available-for-sale securities	66,291	65,461
Fair Value, Measurements, Recurring [Member] \| Collateralized Mortgage Backed Securities [Member]
Available-for-sale securities	51,488	53,544
Fair Value, Measurements, Recurring [Member] \| US Treasury Securities [Member]
Available-for-sale securities	20,740	21,172
Fair Value, Measurements, Recurring [Member] \| US States and Political Subdivisions Debt Securities [Member]
Available-for-sale securities	24,237	26,218
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	54,962	59,118
Restricted cash and cash equivalents	11,778	8,303
Total financial assets	254,667	270,751
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Equity Securities [Member]
Available-for-sale securities	123,568	139,085
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Corporate Debt Securities [Member]
Available-for-sale securities	43,619	43,073
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member] \| Collateralized Mortgage 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	20,740	21,172
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	98,397	102,150
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	22,672	22,388
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member] \| Collateralized Mortgage Backed Securities [Member]
Available-for-sale securities	51,488	53,544
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	$ 24,237	$ 26,218