BUSINESS COMBINATIONS BUSINESS COMBINATIONS (Schedule of Acquisition-Related Costs) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Business Acquisition [Line Items]
Acquisition-related costs recognized in non-interest expenses:	$ 6,813	$ 1,648
Salary and Employee Benefits [Member]
Business Acquisition [Line Items]
Acquisition-related costs recognized in non-interest expenses:	1,313	0
Occupancy and Equipment [Member]
Business Acquisition [Line Items]
Acquisition-related costs recognized in non-interest expenses:	1,949	24
Advertising and Marketing [Member]
Business Acquisition [Line Items]
Acquisition-related costs recognized in non-interest expenses:	251	66
Information and Computer Data Services [Member]
Business Acquisition [Line Items]
Acquisition-related costs recognized in non-interest expenses:	1,417	40
Professional Services [Member]
Business Acquisition [Line Items]
Acquisition-related costs recognized in non-interest expenses:	852	1,280
Miscellaneous
Business Acquisition [Line Items]
Acquisition-related costs recognized in non-interest expenses:	1,031	238
Siuslaw Financial Group, Inc [Member]
Business Acquisition [Line Items]
Acquisition-related costs recognized in non-interest expenses:	0	670
Starbuck Bancshares, Inc [Member]
Business Acquisition [Line Items]
Acquisition-related costs recognized in non-interest expenses:	$ 6,813	$ 978