Note 9 - Investments in Marketable Securities - Amortized Cost and Estimated Fair Value of Debt Securities as Available for Sale (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Within 1 year, cost	$ 11,139	$ 11,448
Within 1 year, fair value	11,153	11,401
1 to 5 years, cost	90,140	98,487
1 to 5 years, fair value	92,120	97,430
6 to 10 years, cost	44,820	64,932
6 to 10 years, fair value	46,284	62,527
Over 10 years, cost	0	1,200
Over 10 years, fair value	0	1,235
Cost	146,099	176,067
Fair Value	$ 149,557	$ 172,593

Amortized cost 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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