Investment Securities, Securities in Continuous Unrealized Loss Position (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2017 USD ($) Security	Dec. 31, 2016 USD ($)	Mar. 31, 2016 USD ($)
Investment Securities [Abstract]
Number of investment securities held | Security	479
Less than 12 months, number of positions | Security	198
12 months or more, number of positions | Security	0
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	$ 264,391	$ 250,069	$ 41,525
Less than 12 months, unrealized loss	2,092	1,905	8
12 months or more, fair value	0	0	0
12 months or more, unrealized loss	0	0	0
Total, fair value	264,391	250,069	41,525
Total, unrealized loss	2,092	1,905	8
Held-to-maturity Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	4,278	7,251
Less than 12 months, unrealized loss	22	40
12 months or more, fair value	0	0
12 months or more, unrealized loss	0	0
Total, fair value	4,278	7,251
Total, unrealized loss	22	40
Government Agency & Government-Sponsored Entities [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value			39,996
Less than 12 months, unrealized loss	$ 0	0	1
12 months or more, fair value			0
12 months or more, unrealized loss			0
Total, fair value			39,996
Total, unrealized loss			1
Less than 12 months, number of positions | Security	0
12 months or more, number of positions | Security	0
US Treasury Notes [Member]
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, fair value	$ 69,433	99,429
Less than 12 months, unrealized loss	300	332	0
12 months or more, fair value	0	0
12 months or more, unrealized loss	0	0
Total, fair value	69,433	99,429
Total, unrealized loss	$ 300	332
Less than 12 months, number of positions | Security	5
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	$ 26,412	27,483
Less than 12 months, unrealized loss	247	260
12 months or more, fair value	0	0
12 months or more, unrealized loss	0	0
Total, fair value	26,412	27,483
Total, unrealized loss	$ 247	260
Less than 12 months, number of positions | Security	135
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	$ 168,546	123,157	1,529
Less than 12 months, unrealized loss	1,545	1,313	7
12 months or more, fair value	0	0	0
12 months or more, unrealized loss	0	0	0
Total, fair value	168,546	123,157	1,529
Total, unrealized loss	$ 1,545	1,313	$ 7
Less than 12 months, number of positions | Security	47
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	$ 4,278	7,251
Less than 12 months, unrealized loss	22	40
12 months or more, fair value	0	0
12 months or more, unrealized loss	0	0
Total, fair value	4,278	7,251
Total, unrealized loss	$ 22	$ 40
Less than 12 months, number of positions | Security	11
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%