Note 8 - Investments in Marketable Securities - Marketable Securities and Restricted Marketable Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Restricted investments available for sale, amortized cost	$ 164,225	$ 185,968
Investments available for sale, amortized cost	194,401	216,144
Available-for-sale securities	312,091	321,717
Equity Securities [Member]
Unrestricted investments available for sale, fair value	148,137	138,013
Unrestricted investments available for sale, amortized cost	30,176	30,176
Corporate Debt Securities [Member]
Restricted investments available for sale, amortized cost	67,997	71,311
Restricted investments available for sale, fair value	68,496	71,100
Commercial Mortgage Backed Securities [Member]
Restricted investments available for sale, amortized cost	51,188	56,889
Restricted investments available for sale, fair value	50,905	56,168
US Government Corporations and Agencies Securities [Member]
Restricted investments available for sale, amortized cost	20,899	25,748
Restricted investments available for sale, fair value	20,533	25,181
US States and Political Subdivisions Debt Securities [Member]
Restricted investments available for sale, amortized cost	24,141	32,020
Restricted investments available for sale, fair value	$ 24,020	$ 31,255

This item represents the cost of debt securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section S99
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This item represents the cost of equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments for other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

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

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Amount of investments in equity securities and other forms of securities that provide ownership interests classified as available-for-sale, expected to be converted to cash, sold or exchanged within one year or the normal operating cycle, if longer.

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Total debt and equity financial instruments including: (1) securities held-to-maturity, (2) trading securities, and (3) securities available-for-sale that are pledged to one or more secured parties who have the right to buy, sell, or re-pledge the collateral.

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