ACQUISITIONS Selected Pro Forma Results (Details 2) - Island Bancorp, Inc. [Member] - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Business Acquisition [Line Items]
Net interest income after provision for loan losses	$ 63,370	$ 57,352	$ 124,412	$ 113,102
Net income	$ 22,698	$ 20,629	$ 44,109	$ 39,488

The pro forma net Income or Loss for the period as if the business combination or combinations had been completed at the beginning of a period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (h)(2)-(3)
-URI http://asc.fasb.org/extlink&oid=65885119&loc=d3e1392-128463

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Period Type:	duration