Goodwill and Intangible Assets (Details Textuals) $ in Thousands	3 Months Ended	9 Months Ended	12 Months Ended
	Mar. 31, 2016 USD ($) acquisition	Sep. 30, 2016 USD ($)	Dec. 31, 2015 USD ($)
Business Acquisition [Line Items]
Goodwill acquired during period	$ 3,000
Additions to finite-lived intangible assets	$ 1,000		$ 12,000
Number of acquisitions | acquisition	2
Goodwill		$ 971,951	968,844
Fully amortized core deposits intangibles		15,000
Goodwill, Impairment Loss		$ 0	$ 0