Organization (Details Textual)	3 Months Ended	9 Months Ended
	Sep. 30, 2017 USD ($)	Sep. 30, 2017 USD ($) acquisition bank_branch
Business Acquisition [Line Items]
Number of Businesses Acquired | acquisition		28
New accounting pronouncement for change in accounting principle effect of change of income taxes	$ 0	$ 1,500,000
FDIC Insurance Limits	250,000	250,000
Retained Earnings
Business Acquisition [Line Items]
Cumulative effect of change in accounting principle	420,000	420,000
New Policies [Member]
Business Acquisition [Line Items]
Time Deposits, Less Than $250,000	250,000	250,000
Time Deposits, $250,000 or More	250,000	250,000
Expired Policies [Member]
Business Acquisition [Line Items]
Time Deposits, Less than $100,000	100,000	100,000
Time Deposits, $100,000 or More	$ 100,000	$ 100,000
CALIFORNIA
Business Acquisition [Line Items]
Retail Branch Locations | bank_branch		74
NORTH CAROLINA
Business Acquisition [Line Items]
Retail Branch Locations | bank_branch		1