Note 8 - Fair Value Measurements (Detail) - Summary of Fair Value Measurements by Level (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Cash and cash equivalents	$ 73,839	$ 66,701
Restricted cash and cash equivalents	17,376	11,563
Available for sale securities	258,359	242,457
Total financial assets	349,574	320,721
Marketable Equity Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Available for sale securities	123,577	107,250
Marketable Equity Securities [Member]
Available for sale securities	123,577	107,250
Corporate Debt Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Available for sale securities	58,615	62,876
Corporate Debt Securities [Member]
Available for sale securities	58,615	62,876
Commercial Mortgage Backed Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Available for sale securities	53,808	48,063
Commercial Mortgage Backed Securities [Member]
Available for sale securities	53,808	48,063
US Treasury Securities [Member] \| Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents		16,604
Available for sale securities	14,704
US Treasury Securities [Member]
Cash and cash equivalents		16,604
Available for sale securities	14,704
State and Municipal Securities [Member] \| Fair Value, Inputs, Level 2 [Member]
Available for sale securities	7,655	7,664
State and Municipal Securities [Member]
Available for sale securities	7,655	7,664
Fair Value, Inputs, Level 1 [Member]
Cash and cash equivalents	73,839	66,701
Restricted cash and cash equivalents	17,376	11,563
Total financial assets	229,496	202,118
Fair Value, Inputs, Level 2 [Member]
Total financial assets	$ 120,078	$ 118,603

This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item represents Available-for-sale Securities which consist of all investments in certain debt and equity securities neither classified as trading or held-to-maturity securities. A debt security represents a creditor relationship with an enterprise. Debt securities include, among other items, US Treasury securities, US government securities, municipal securities, corporate bonds, convertible debt, commercial paper, and all securitized debt instruments. An equity security represents an ownership interest in an enterprise or the right to acquire or dispose of an ownership interest in an enterprise at fixed or determinable prices. Equity securities include, among other things, common stock, certain preferred stock, warrant rights, call options, and put options, but do not include convertible debt. An entity may opt to provide the reader with additional narrative text to better understand the nature of investments in debt and equity securities which are categorized as Available-for-sale.

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This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. This item includes currency on hand as well as demand deposits with banks or financial institutions. It also includes other kinds of accounts that have the general characteristics of demand deposits in that the Company may deposit additional funds at any time and also effectively may withdraw funds at any time without prior notice or penalty. Cash equivalents, excluding items classified as marketable securities, include short-term, highly liquid investments that are both readily convertible to known amounts of cash, and so near their maturity that they present minimal risk of changes in value because of changes in interest rates. Generally, only investments with original maturities of three months or less qualify under that definition. Original maturity means original maturity to the entity holding the investment. For example, both a three-month US Treasury bill and a three-year Treasury note purchased three months from maturity qualify as cash equivalents. However, a Treasury note purchased three years ago does not become a cash equivalent when its remaining maturity is three months.

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- Definition

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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