Securities (Unrealized Loss NOT deemed to be OTTI) (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014 holding	Dec. 31, 2013 holding
Summary of gross unrealized losses and fair value of investments
No of holdings	182	221
Fair value, less than 12 months	$ 331,980	$ 433,230
Unrealized losses, less than 12 months	(8,037)	(13,520)
Fair value, 12 months or longer	33,565	10,928
Unrealized losses, 12 months or longer	(3,637)	(2,490)
Fair value, Total	365,545	444,158
Unrealized losses, Total	(11,674)	(16,010)
U. S. Government Agency Securities [Member]
Summary of gross unrealized losses and fair value of investments
No of holdings	38	39
Fair value, less than 12 months	38,961	39,950
Unrealized losses, less than 12 months	(415)	(885)
Fair value, 12 months or longer
Unrealized losses, 12 months or longer
Fair value, Total	38,961	39,950
Unrealized losses, Total	(415)	(885)
Agency Mortgage-Backed Securities [Member]
Summary of gross unrealized losses and fair value of investments
No of holdings	110	124
Fair value, less than 12 months	165,251	202,004
Unrealized losses, less than 12 months	(2,797)	(5,217)
Fair value, 12 months or longer	6,193	5,108
Unrealized losses, 12 months or longer	(336)	(372)
Fair value, Total	171,444	207,112
Unrealized losses, Total	(3,133)	(5,589)
Agency Collateralized Mortgage Obligations [Member]
Summary of gross unrealized losses and fair value of investments
No of holdings	15	19
Fair value, less than 12 months	125,217	183,721
Unrealized losses, less than 12 months	(4,766)	(7,278)
Fair value, 12 months or longer	21,186	0
Unrealized losses, 12 months or longer	(1,529)	0
Fair value, Total	146,403	183,721
Unrealized losses, Total	(6,295)	(7,278)
US States and Political Subdivisions Debt Securities [Member]
Summary of gross unrealized losses and fair value of investments
No of holdings	1	13
Fair value, less than 12 months	289	3,838
Unrealized losses, less than 12 months	(1)	(28)
Fair value, 12 months or longer	0	0
Unrealized losses, 12 months or longer	0	0
Fair value, Total	289	3,838
Unrealized losses, Total	(1)	(28)
Pooled Trust Preferred Securities Issued by Banks and Insurers [Member]
Summary of gross unrealized losses and fair value of investments
No of holdings	2	2
Fair value, less than 12 months	0
Unrealized losses, less than 12 months	0
Fair value, 12 months or longer	2,593	2,300
Unrealized losses, 12 months or longer	(1,583)	(1,913)
Fair value, Total	2,593	2,300
Unrealized losses, Total	(1,583)	(1,913)
Single Trust Preferred Securities [Member]
Summary of gross unrealized losses and fair value of investments
No of holdings		2
Fair value, less than 12 months		1,341
Unrealized losses, less than 12 months		22
Fair value, 12 months or longer		0
Unrealized losses, 12 months or longer		0
Fair value, Total		1,341
Unrealized losses, Total		22
Marketable Equity Securities [Member]
Summary of gross unrealized losses and fair value of investments
No of holdings	16	22
Fair value, less than 12 months	2,262	2,376
Unrealized losses, less than 12 months	(58)	(90)
Fair value, 12 months or longer	3,593	3,520
Unrealized losses, 12 months or longer	(189)	(205)
Fair value, Total	5,855	5,896
Unrealized losses, Total	$ (247)	$ (295)