Securities (Reconciliation of fair value of securities) (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	$ 400,665	$ 363,366
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	4,241	3,890
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(3,069)	(3,612)
Available-for-sale Securities	401,837	363,644
Held to maturity Securities, Amortized Cost	502,123	487,076
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	3,659	3,556
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(4,865)	(4,982)
Held to Maturity, Fair Value, Total	500,917	485,650
Amortized Cost	902,788	850,442
Gross Unrealized Gains	7,900	7,446
Unrealized Losses Other	(7,934)	(8,594)
Fair Value	902,754	849,294
U. S. Government Agency Securities [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	24,007	24,006
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	262	238
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	0	0
Available-for-sale Securities	24,269	24,244
U.S. Treasury securities
Reconciliation of fair value of securities
Held to maturity Securities, Amortized Cost	1,007	1,007
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	45	47
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	0
Held to Maturity, Fair Value, Total	1,052	1,054
Agency mortgage-backed securities
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	186,103	173,268
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	2,729	2,852
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(498)	(736)
Available-for-sale Securities	188,334	175,384
Held to maturity Securities, Amortized Cost	184,317	156,088
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	2,283	2,274
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(1,024)	(858)
Held to Maturity, Fair Value, Total	185,576	157,504
Agency Collateralized Mortgage Obligations [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	126,017	101,094
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	182	106
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(1,331)	(1,332)
Available-for-sale Securities	124,868	99,868
Held to maturity Securities, Amortized Cost	284,716	297,445
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	1,065	1,002
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(3,657)	(3,797)
Held to Maturity, Fair Value, Total	282,124	294,650
State, County, and Municipal Securities [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	3,733	3,743
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	54	50
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	0	0
Available-for-sale Securities	3,787	3,793
Single Issuer Trust Preferred Securities Issued by Banks and Insurers [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	2,298	2,311
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	22	3
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	0	(3)
Available-for-sale Securities	2,320	2,311
Held to maturity Securities, Amortized Cost	1,500	1,500
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	38	44
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	0
Held to Maturity, Fair Value, Total	1,538	1,544
Pooled trust preferred securities issued by banks and insurers
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	2,201	2,200
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	0	0
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(605)	(616)
Available-for-sale Securities	1,596	1,584
Small Business Administration Pooled Securities [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	37,140	37,561
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	28	0
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(166)	(372)
Available-for-sale Securities	37,002	37,189
Held to maturity Securities, Amortized Cost	30,583	31,036
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	228	189
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(184)	(327)
Held to Maturity, Fair Value, Total	30,627	30,898
Equity securities
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	19,166	19,183
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	964	641
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(469)	(553)
Available-for-sale Securities	$ 19,661	$ 19,271

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Amount before tax of unrealized gain in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.

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Amount before tax of unrealized loss in accumulated other comprehensive income (AOCI) on investments in debt securities classified as available-for-sale.

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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

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