Note 20 - Stock Repurchase Program (Details Textual) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	6 Months Ended	8 Months Ended	12 Months Ended
	Jun. 30, 2019	Jun. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	May 07, 2019	Oct. 26, 2018
Treasury Stock, Value, Acquired, Cost Method	$ 23,008	$ 31,609
October 26, 2018 Stock Repurchase Program [Member]
Stock Repurchase Program, Authorized Amount						$ 45,000
Treasury Stock, Shares, Acquired		268,660	1,182,060	913,400
Treasury Stock, Value, Acquired, Cost Method		$ 9,900		$ 35,100
Treasury Stock Acquired, Average Cost Per Share		$ 36.83	$ 38.07	$ 38.43
May 2019 Repurchase Program [Member]
Stock Repurchase Program, Authorized Amount					$ 50,000
Treasury Stock, Shares, Acquired	606,934
Treasury Stock, Value, Acquired, Cost Method	$ 21,700
Treasury Stock Acquired, Average Cost Per Share	$ 35.78
Stock Repurchase Program, Remaining Authorized Repurchase Amount	$ 28,300	$ 28,300	$ 28,300