Investment Securities, Part II (Details) (USD $)	3 Months Ended	6 Months Ended
	Jun. 30, 2014 securities	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
One year or less	$ 126,646,000	$ 126,646,000
After 1 through 5 years	187,388,000	187,388,000
After 5 through 10 years	122,694,000	122,694,000
After ten years	2,462,000	2,462,000
Fair Value	439,190,000	439,190,000		488,724,000
Available-for-sale, Weighted Average Yield, Maturities Year One (in hundredths)		1.67%
Available-for-sale , Weighted Average Yield, Maturities After 1 through 5 Years (in hundredths)		2.50%
Available-for-sale, Weighted Average Yield, Maturities After 5 through 10 Years (in hundredths)		2.55%
Available-for-sale , Weighted Average Yield, Maturities After 10 Years (in hundredths)		1.64%
Available-for-sale , Weighted Average Yield, Maturities (in hundredths)		2.26%
Available-for-sale, Full Tax-equivalent Yield, Maturities Year One (in hundredths)		1.75%
Available-for-sale, Full Tax-equivalent Yield, Maturities After 1 through 5 Years (in hundredths)		2.96%
Available-for-sale, Full Tax-equivalent Yield, Maturities After 5 through 10 years (in hundredths)		3.17%
Available-for-sale, Full Tax-equivalent Yield, Maturities After Ten Years (in hundredths)		2.37%
Available-for-sale, Full Tax-equivalent Yield, Maturities (in hundredths)		2.66%
Tax rate used to calculate tax-equivalent yields (in hundredths)		35.00%
Percentage investment book value exceeds total stockholders' equity (in hundredths)		10.00%
Investment Securities Pledged as Collateral	285,000,000	285,000,000		321,000,000
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Fair Value	40,589,000	40,589,000		348,118,000
Less than 12 months, Unrealized Losses	(319,000)	(319,000)		(13,624,000)
12 months or longer, Fair Value	234,488,000	234,488,000		1,012,000
12 months or longer, Unrealized losses	(9,297,000)	(9,297,000)		(3,526,000)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	275,077,000	275,077,000		349,130,000
Total Unrealized Losses	9,616,000	9,616,000		17,150,000
Details of Trust Preferred Securities [Abstract]
Coupon Rate of Trust Preferred Security		floating rate coupon of 3-month LIBOR plus 90 basis points
Number of Ratios Utilized in OTTI Credit Model		29
OTTI Cash Flow Initial Default Rate		2.00%
Period For Initial Default Rate Used In OTTI Analysis		two years
Default Rate Applied For Remainder Of OTTI Analysis		36 basis points
Recovery Rate Used In OTTI Cash Flow Analysis		10.00%
Credit losses on trust preferred securities held [Abstract]
Beginning of period		1,111,000	3,989,000
Additions related to OTTI losses not previously recognized		0	0
Reductions due to sales / (recoveries)		0	0
Reductions due to change in intent or likelihood of sale		0	0
Additions related to increases in previously recognized OTTI losses		0	0
Reductions due to increases in expected cash flows		0	0
End of period	1,111,000	1,111,000	3,989,000
Number Of Trust Preferred Securities Sold	2
PreTSL XXVIII [Member]
Details of Trust Preferred Securities [Abstract]
Book Value	3,449,000	3,449,000
Market Value	369,000	369,000
Unrealized Gains (Losses)	(3,080,000)	(3,080,000)
Other-than- temporary Impairment Recorded To-date		(1,111,000)
U.S. Treasury securities and obligations of U.S. government corporations & agencies
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
One year or less	120,920,000	120,920,000
After 1 through 5 years	34,500,000	34,500,000
After 5 through 10 years	4,816,000	4,816,000
After ten years	0	0
Fair Value	160,236,000	160,236,000		190,368,000
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Fair Value	4,926,000	4,926,000		183,074,000
Less than 12 months, Unrealized Losses	(74,000)	(74,000)		(7,574,000)
12 months or longer, Fair Value	137,393,000	137,393,000		0
12 months or longer, Unrealized losses	(3,759,000)	(3,759,000)		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	142,319,000	142,319,000		183,074,000
Total Unrealized Losses	3,833,000	3,833,000		7,574,000
Number of securities in Unrealized Loss Positions	30	30
Obligations of states and political subdivisions
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
One year or less	3,560,000	3,560,000
After 1 through 5 years	32,518,000	32,518,000
After 5 through 10 years	31,499,000	31,499,000
After ten years	2,033,000	2,033,000
Fair Value	69,610,000	69,610,000		64,562,000
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Fair Value	6,440,000	6,440,000		29,986,000
Less than 12 months, Unrealized Losses	(41,000)	(41,000)		(1,708,000)
12 months or longer, Fair Value	11,289,000	11,289,000		808,000
12 months or longer, Unrealized losses	(302,000)	(302,000)		(65,000)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	17,729,000	17,729,000		30,794,000
Total Unrealized Losses	343,000	343,000		1,773,000
Number of securities in Unrealized Loss Positions	25	25		2
Mortgage-backed securities: GSE residential
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
One year or less	2,166,000	2,166,000
After 1 through 5 years	120,370,000	120,370,000
After 5 through 10 years	82,407,000	82,407,000
After ten years	0	0
Fair Value	204,943,000	204,943,000		227,601,000
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Fair Value	29,223,000	29,223,000		131,125,000
Less than 12 months, Unrealized Losses	(204,000)	(204,000)		(4,275,000)
12 months or longer, Fair Value	83,470,000	83,470,000		13,000
12 months or longer, Unrealized losses	(2,123,000)	(2,123,000)		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	112,693,000	112,693,000		131,138,000
Total Unrealized Losses	2,327,000	2,327,000		4,275,000
Number of securities in Unrealized Loss Positions	29	29		1
Trust preferred securities
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
One year or less	0	0
After 1 through 5 years	0	0
After 5 through 10 years	0	0
After ten years	369,000	369,000
Fair Value	369,000	369,000		191,000
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Fair Value	0	0		0
Less than 12 months, Unrealized Losses	0	0		0
12 months or longer, Fair Value	369,000	369,000		191,000
12 months or longer, Unrealized losses	(3,080,000)	(3,080,000)		(3,461,000)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	369,000	369,000		191,000
Total Unrealized Losses	3,080,000	3,080,000		3,461,000
Number of securities in Unrealized Loss Positions	1	1		1
Credit losses on trust preferred securities held [Abstract]
Available-for-sale Securities, Gross Realized Gains (Losses), Sale Proceeds	1,400,000
Other securities
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
One year or less	0	0
After 1 through 5 years	0	0
After 5 through 10 years	3,972,000	3,972,000
After ten years	60,000	60,000
Fair Value	4,032,000	4,032,000		6,002,000
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Fair Value	0	0		3,933,000
Less than 12 months, Unrealized Losses	0	0		(67,000)
12 months or longer, Fair Value	1,967,000	1,967,000		0
12 months or longer, Unrealized losses	(33,000)	(33,000)		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	1,967,000	1,967,000		3,933,000
Total Unrealized Losses	$ 33,000	$ 33,000		$ 67,000
Number of securities in Unrealized Loss Positions	1	1