Securities - Realized Gains and Losses (Narrative) (Details)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) security	Jun. 30, 2016 USD ($)	Dec. 31, 2016 USD ($)
Schedule of Investments [Line Items]
Available-for-sale Securities, impairment on securities					$ 0
Available-for-sale securities, realized gains	$ 74,000	$ 81,000	$ 74,000	$ 175,000
Available-for-sale Securities, gross realized gain (loss)	16,000	$ 81,000	16,000	$ 175,000
Available-for-sale Securities pledged as collateral	20,400,000		$ 20,400,000		$ 17,700,000
Residential mortgage-backed securities | 3 Securities Sold
Schedule of Investments [Line Items]
Number of securities sold | security			3
Available-for-sale Securities, book value	1,200,000		$ 1,200,000
Available-for-sale Securities, gross realized gain (loss)			$ 71,000
Residential mortgage-backed securities | 2 Securities Sold
Schedule of Investments [Line Items]
Number of securities sold | security			2
Available-for-sale Securities, book value	1,600,000		$ 1,600,000
Available-for-sale Securities, gross realized gain (loss)			$ (58,000)
Asset-backed securities
Schedule of Investments [Line Items]
Number of securities sold | security			2
Available-for-sale Securities, book value	3,500,000		$ 3,500,000
Available-for-sale Securities, gross realized gain (loss)			$ 3,000
Municipal Securities
Schedule of Investments [Line Items]
Number of securities sold | security			15
Available-for-sale Securities, book value	6,400,000		$ 6,400,000
Available-for-sale Securities, gross realized gain (loss)			$ 112,000
Equity Securities
Schedule of Investments [Line Items]
Number of securities sold | security			1
Available-for-sale Securities, book value	$ 40,000		$ 40,000
Available-for-sale Securities, gross realized gain (loss)			$ 63,000