Investment Securities Held to Maturity Securities by Type (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	$ 357,890	$ 393,855
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	2,741	387
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(407)	(10,249)
Securities held to maturity, fair value	360,224	383,993
US Government Agencies Residential Mortgage-backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	3,549	3,635
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	57	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	(97)
Securities held to maturity, fair value	3,606	3,538
US Government Agency Debt Securities Commercial [Domain]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	54,244	55,221
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	173	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(106)	(2,327)
Securities held to maturity, fair value	54,311	52,894
Residential Mortgage Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	245,238	279,109
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	1,762	212
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(297)	(7,254)
Securities held to maturity, fair value	246,703	272,067
Obligations of U.S. Government-Sponsored Enterprises - Mortgage-Backed Securities - Commercial [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	12,361	13,159
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	123	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	(258)
Securities held to maturity, fair value	12,484	12,901
Obligations of States and Political Subdivisions [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	41,898	42,331
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	626	175
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	(313)
Securities held to maturity, fair value	42,524	42,193
Debt Security, Government, Non-US [Member]
Schedule of Held-to-maturity Securities [Line Items]
Debt Securities, Held-to-maturity	600	400
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(4)	0
Securities held to maturity, fair value	$ 596	$ 400