Investment Securities (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014 securities	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Available-for-sale: [Abstract]
Amortized Cost	$ 444,595		$ 444,595		$ 502,457
Gross Unrealized Gains	4,211		4,211		3,417
Gross Unrealized (Losses)	(9,616)		(9,616)		(17,150)
Fair Value	439,190		439,190		488,724
Number Of Trust Preferred Securities Sold	2
Gain (Loss) on Sale of Securities, Net	543	482	734	835
Realized Investment Gains (Losses) [Abstract]
Gross gains			1,435	835
Gross losses			(701)	0
U.S. Treasury securities and obligations of U.S. government corporations & agencies
Available-for-sale: [Abstract]
Amortized Cost	163,914		163,914		197,805
Gross Unrealized Gains	155		155		137
Gross Unrealized (Losses)	(3,833)		(3,833)		(7,574)
Fair Value	160,236		160,236		190,368
Obligations of states and political subdivisions
Available-for-sale: [Abstract]
Amortized Cost	67,786		67,786		65,304
Gross Unrealized Gains	2,167		2,167		1,031
Gross Unrealized (Losses)	(343)		(343)		(1,773)
Fair Value	69,610		69,610		64,562
Mortgage-backed securities: GSE residential
Available-for-sale: [Abstract]
Amortized Cost	205,411		205,411		229,661
Gross Unrealized Gains	1,859		1,859		2,215
Gross Unrealized (Losses)	(2,327)		(2,327)		(4,275)
Fair Value	204,943		204,943		227,601
Trust preferred securities
Available-for-sale: [Abstract]
Amortized Cost	3,449		3,449		3,652
Gross Unrealized Gains	0		0		0
Gross Unrealized (Losses)	(3,080)		(3,080)		(3,461)
Fair Value	369		369		191
Number of trust preferred securities			1
Trust preferred securities | Maximum [Member]
Available-for-sale: [Abstract]
Maturities of Debt Securities			twenty-three years
Other securities
Available-for-sale: [Abstract]
Amortized Cost	4,035		4,035		6,035
Gross Unrealized Gains	30		30		34
Gross Unrealized (Losses)	(33)		(33)		(67)
Fair Value	$ 4,032		$ 4,032		$ 6,002