Note 2 - Acquisition (Details Textual) - USD ($) $ in Thousands		12 Months Ended
	Jul. 31, 2015	Dec. 31, 2015	Dec. 31, 2016
Goodwill		$ 372,189	$ 372,189
Asia Bancshares [Member]
Business Combination, Purchase Consideration Percentage of Equity Interest	55.00%
Business Combination, Purchase Consideration Percentage of Cash	45.00%
Business Combination, Consideration Transferred	$ 139,863	139,863
Business Acquisition, Equity Interest Issued or Issuable, Number of Shares	2,580,359
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned	$ 82,900
Payments to Acquire Businesses, Gross	57,006	57,006
Goodwill	$ 55,849	$ 55,849