Securities (Reconciliation of fair value of securities) (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	$ 369,438	$ 365,140
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	10,214	5,252
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(1,425)	(3,143)
Available-for-sale Securities	378,227	367,249
Held to maturity Securities, Amortized Cost	457,641	477,507
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	11,130	5,177
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(1,007)	(3,935)
Held to Maturity, Fair Value, Total	467,764	478,749
Amortized Cost	827,079	842,647
Gross Unrealized Gains	21,344	10,429
Unrealized Losses Other	(2,432)	(7,078)
Fair Value	845,991	845,998
U. S. Government Agency Securities [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	29,466	29,958
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	856	261
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	0	(4)
Available-for-sale Securities	30,322	30,215
U.S. Treasury securities
Reconciliation of fair value of securities
Held to maturity Securities, Amortized Cost	1,008	1,009
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	84	55
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	0
Held to Maturity, Fair Value, Total	1,092	1,064
Agency mortgage-backed securities
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	200,081	207,693
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	6,950	4,227
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(20)	(983)
Available-for-sale Securities	207,011	210,937
Held to maturity Securities, Amortized Cost	161,452	167,134
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	6,123	3,460
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	(219)
Held to Maturity, Fair Value, Total	167,575	170,375
Agency Collateralized Mortgage Obligations [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	76,481	64,157
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	1,001	179
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(325)	(752)
Available-for-sale Securities	77,157	63,584
Held to maturity Securities, Amortized Cost	258,620	267,348
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	3,866	1,195
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	(1,007)	(3,652)
Held to Maturity, Fair Value, Total	261,479	264,891
State, County, and Municipal Securities [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	4,529	4,543
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	127	116
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	0	0
Available-for-sale Securities	4,656	4,659
Held to maturity Securities, Amortized Cost	225	225
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	0	2
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	0
Held to Maturity, Fair Value, Total	225	227
Single Issuer Trust Preferred Securities Issued by Banks and Insurers [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	2,350	2,865
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	8	8
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(125)	(81)
Available-for-sale Securities	2,233	2,792
Held to maturity Securities, Amortized Cost	1,500	1,500
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	17	22
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	0
Held to Maturity, Fair Value, Total	1,517	1,522
Pooled trust preferred securities issued by banks and insurers
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	2,216	2,217
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	0	0
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(716)	(645)
Available-for-sale Securities	1,500	1,572
Small Business Administration Pooled Securities [Member]
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	39,942	40,472
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	849	87
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	0	(110)
Available-for-sale Securities	40,791	40,449
Held to maturity Securities, Amortized Cost	34,836	35,291
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	1,040	437
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	(64)
Held to Maturity, Fair Value, Total	35,876	35,664
Equity securities
Reconciliation of fair value of securities
Available for sale Securities, Amortized Cost	14,373	13,235
Available-for-sale Debt Securities, Accumulated Gross Unrealized Gain, before Tax	423	374
Available-for-sale Debt Securities, Accumulated Gross Unrealized Loss, before Tax	(239)	(568)
Available-for-sale Securities	14,557	13,041
Corporate debt securities
Reconciliation of fair value of securities
Held to maturity Securities, Amortized Cost	0	5,000
Held-to-maturity Securities, Accumulated Unrecognized Holding Gain	0	6
Held-to-maturity Securities, Accumulated Unrecognized Holding Loss	0	0
Held to Maturity, Fair Value, Total	$ 0	$ 5,006