Investment Securities Maturities of Held to Maturity Securities by Type (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Amortized cost
Amortized Cost	$ 70,438	$ 74,576
Fair value
Total	68,595	73,781
U.S. government and agencies
Amortized cost
Within one year	9,898
After one, but within five years	0
After five, but within ten years	0
Greater than ten years	0
Amortized Cost	9,898
Fair value
Within one year	9,900
After one, but within five years	0
After five, but within ten years	0
Greater than ten years	0
Total	$ 9,900
Weighted average yield
Within one year	2.52%
After one, but within five years	0.00%
After five, but within ten years	0.00%
Greater than ten years	0.00%
Total	2.52%
Mortgage-backed securities
Amortized cost
Within one year	$ 0
After one, but within five years	0
After five, but within ten years	45,979
Greater than ten years	14,561
Amortized Cost	60,540	74,576
Fair value
Within one year	0
After one, but within five years	0
After five, but within ten years	44,591
Greater than ten years	14,104
Total	$ 58,695	$ 73,781
Weighted average yield
Within one year	0.00%
After one, but within five years	0.00%
After five, but within ten years	2.21%
Greater than ten years	2.46%
Total	2.27%