Mergers and Acquisitions - Net Liabilities Assumed (Details) - USD ($) $ in Thousands	Sep. 30, 2015	Aug. 28, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013
Business Acquisition [Line Items]
Goodwill	$ 18,480		$ 17,779	$ 17,779	$ 17,779
Susquehanna Bank [Member]
Business Acquisition [Line Items]
Cash received in transaction	$ 69,000	$ 47,962
Branch cash		330
Loans		18,200
Bank premises, furniture and equipment		609
AIR and other assets		62
Core deposit intangible		878
Net assets assumed		68,041
Deposits		68,697
Accrued interest payable and other liabilities		45
Liabilities assumed		68,742
Net liabilities assumed		(701)
Goodwill		$ 701
Total liabilities assumed