Securities (Reconciliation of fair value of securities) (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Reconciliation of fair value of securities
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	$ 2,224	$ 1,233
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(3,842)	(9,029)
Debt Securities, Available-for-sale	437,689	442,752
Debt Securities, Available-for-sale, Amortized Cost	439,307	450,548
Held to maturity Securities, Amortized Cost	623,243	611,490
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	5,574	2,533
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(5,661)	(10,383)
Held to Maturity, Fair Value, Total	623,156	603,640
Amortized Cost	1,062,550	1,062,038
Gross Unrealized Gains	7,798	3,766
Unrealized Losses Other	(9,503)	(19,412)
Debt Securities, Available-for-sale and Held-to-maturity	1,060,845	1,046,392
U.S. Government agency securities
Reconciliation of fair value of securities
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	25
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(47)	(439)
Debt Securities, Available-for-sale	32,455	32,038
Debt Securities, Available-for-sale, Amortized Cost	32,477	32,477
U.S. Treasury securities
Reconciliation of fair value of securities
Held to maturity Securities, Amortized Cost	1,004	1,004
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	13	11
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	0	0
Held to Maturity, Fair Value, Total	1,017	1,015
Agency mortgage-backed securities
Reconciliation of fair value of securities
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1,674	1,020
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(1,042)	(3,406)
Debt Securities, Available-for-sale	217,795	220,105
Debt Securities, Available-for-sale, Amortized Cost	217,163	222,491
Held to maturity Securities, Amortized Cost	259,599	252,484
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	3,238	1,548
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(955)	(3,104)
Held to Maturity, Fair Value, Total	261,882	250,928
Agency Collateralized Mortgage Obligations [Member]
Reconciliation of fair value of securities
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	338	197
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(1,832)	(3,435)
Debt Securities, Available-for-sale	131,531	134,911
Debt Securities, Available-for-sale, Amortized Cost	133,025	138,149
Held to maturity Securities, Amortized Cost	337,804	332,775
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	2,208	869
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(4,307)	(6,920)
Held to Maturity, Fair Value, Total	335,705	326,724
US States and Political Subdivisions Debt Securities [Member]
Reconciliation of fair value of securities
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	23	16
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0	0
Debt Securities, Available-for-sale	1,739	1,735
Debt Securities, Available-for-sale, Amortized Cost	1,716	1,719
Single Issuer Trust Preferred Securities Issued by Banks and Insurers [Member]
Reconciliation of fair value of securities
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	4
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	0	(10)
Debt Securities, Available-for-sale	721	707
Debt Securities, Available-for-sale, Amortized Cost	717	717
Held to maturity Securities, Amortized Cost	1,500	1,500
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	0	0
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(10)	(10)
Held to Maturity, Fair Value, Total	1,490	1,490
Pooled trust preferred securities issued by banks and insurers
Reconciliation of fair value of securities
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	0	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(346)	(349)
Debt Securities, Available-for-sale	1,314	1,329
Debt Securities, Available-for-sale, Amortized Cost	1,660	1,678
Small Business Administration Pooled Securities [Member]
Reconciliation of fair value of securities
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	160	0
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	(575)	(1,390)
Debt Securities, Available-for-sale	52,134	51,927
Debt Securities, Available-for-sale, Amortized Cost	52,549	53,317
Held to maturity Securities, Amortized Cost	23,336	23,727
Debt Securities, Held-to-maturity, Accumulated Unrecognized Gain	115	105
Debt Securities, Held-to-maturity, Accumulated Unrecognized Loss	(389)	(349)
Held to Maturity, Fair Value, Total	$ 23,062	$ 23,483

Available for sale securities and held to maturity securities amortized cost.

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Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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