Note 20 - Stock Repurchase Program (Details Textual) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
Mar. 31, 2019	Dec. 31, 2018	Oct. 26, 2018
Treasury Stock, Shares, Acquired	233,700	913,400
Treasury Stock, Value, Acquired, Cost Method	$ 8,601	$ 35,100
Treasury Stock Acquired, Average Cost Per Share	$ 36.80	$ 38.43
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 1,300
February 2016 Repurchase Program [Member]
Stock Repurchase Program, Authorized Amount			$ 45,000

Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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