Investment Securities, Securities in Continuous Unrealized Loss Position (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2017 USD ($) Security	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)
Investment Securities [Abstract]
Number of investment securities held | Security	485
Less than 12 months, number of positions | Security	156
12 months or more, number of positions | Security	0
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	$ 215,970	$ 250,069	$ 59,993
Less than 12 months, unrealized loss	1,154	1,905	1
12 months or more, fair value	0	0	0
12 months or more, unrealized loss	0	0	0
Total, fair value	215,970	250,069	59,993
Total, unrealized loss	1,154	1,905	1
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value		7,251
Less than 12 months, unrealized loss		40
12 months or more, fair value		0
12 months or more, unrealized loss		0
Total, fair value		7,251
Total, unrealized loss		40
Government Agency & Government-Sponsored Entities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value			59,993
Less than 12 months, unrealized loss			1
12 months or more, fair value			0
12 months or more, unrealized loss			0
Total, fair value			59,993
Total, unrealized loss	0	0	1
US Treasury Notes [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	74,414	99,429
Less than 12 months, unrealized loss	249	332	0
12 months or more, fair value	0	0
12 months or more, unrealized loss	0	0
Total, fair value	74,414	99,429
Total, unrealized loss	$ 249	332
Less than 12 months, number of positions | Security	6
12 months or more, number of positions | Security	0
US Govt SBA [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	$ 18,669	27,483
Less than 12 months, unrealized loss	86	260
12 months or more, fair value	0	0
12 months or more, unrealized loss	0	0
Total, fair value	18,669	27,483
Total, unrealized loss	$ 86	260
Less than 12 months, number of positions | Security	94
12 months or more, number of positions | Security	0
Mortgage Backed Securities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	$ 122,887	123,157
Less than 12 months, unrealized loss	819	1,313	0
12 months or more, fair value	0	0
12 months or more, unrealized loss	0	0
Total, fair value	122,887	123,157
Total, unrealized loss	$ 819	1,313
Less than 12 months, number of positions | Security	55
12 months or more, number of positions | Security	0
Obligations of States and Political Subdivisions [Member]
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value		7,251
Less than 12 months, unrealized loss		40
12 months or more, fair value		0
12 months or more, unrealized loss		0
Total, fair value		7,251
Total, unrealized loss	$ 0	$ 40	$ 0
Less than 12 months, number of positions | Security	0
12 months or more, number of positions | Security	0
Municipal Bonds [Member]
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]
Percentage of bank qualified municipal bond portfolio rated	98.00%
Percentage of portfolio not rated	2.00%