Stock-Based Compensation (Stock-Based Compensation Plans) (Details)	6 Months Ended
	Jun. 30, 2017 shares	Dec. 31, 2016 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options outstanding	176,544	387,630
Jefferson Bancorp, Inc. 2010 Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate number of shares that may be issued to any participant in a calendar year	577,642
Ratio of common stock shares to be received per share of acquiree	2.2217
Term of options	10 years
Options exercise price as a percentage of fair market value	100.00%
Stock options outstanding	55,544	156,072
2015 Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate number of shares that may be issued to any participant in a calendar year	100,000
Grants of shares authorized	30,000	40,000
2015 Equity Plan [Member] | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate number of shares that may be issued to any participant in a calendar year	20,000
2015 Equity Plan [Member] | Employee Stock Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate number of shares that may be issued to any participant in a calendar year	100,000
2007 Equity Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate number of shares that may be issued to any participant in a calendar year	500,000
Stock options outstanding	91,000	191,558