Summary of Significant Accounting Policies (Segment Reporting) (Details)	12 Months Ended
	Dec. 31, 2017 segment
Segment Reporting Information [Line Items]
Number of reportable segments (segment)	2
Community Banking
Segment Reporting Information [Line Items]
Number of reportable segments (segment)	1
Mortgage Banking Operations
Segment Reporting Information [Line Items]
Number of reportable segments (segment)	1