Investment Securities Held-to-maturity Securities (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule of Held-to-maturity Securities
Amortized Cost	$ 43,144,000	$ 45,728,000
Gross Unrealized Gains	653,000	757,000
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	570,000	632,000
Fair Value	43,227,000	45,853,000
Gross realized gains or losses	0	0	$ 0
States and political subdivisions
Schedule of Held-to-maturity Securities
Amortized Cost	3,820,000	3,831,000
Gross Unrealized Gains	221,000	394,000
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	4,000
Fair Value	4,041,000	4,221,000
Residential mortgage-backed securities
Schedule of Held-to-maturity Securities
Amortized Cost	33,858,000	35,367,000
Gross Unrealized Gains	432,000	363,000
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	528,000	534,000
Fair Value	33,762,000	35,196,000
Commercial mortgage-backed securities
Schedule of Held-to-maturity Securities
Amortized Cost	5,466,000	6,530,000
Gross Unrealized Gains	0	0
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	42,000	94,000
Fair Value	$ 5,424,000	$ 6,436,000