Investment Securities, Part II (Details) (USD $)	3 Months Ended
	Mar. 31, 2014 securities	Mar. 31, 2013	Dec. 31, 2013
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
One year or less	$ 138,674,000
After 1 through 5 years	183,242,000
After 5 through 10 years	123,645,000
After ten years	2,290,000
Fair Value	447,851,000		488,724,000
Available-for-sale, Weighted Average Yield, Maturities Year One (in hundredths)	1.65%
Available-for-sale , Weighted Average Yield, Maturities After 1 through 5 Years (in hundredths)	2.57%
Available-for-sale, Weighted Average Yield, Maturities After 5 through 10 Years (in hundredths)	2.60%
Available-for-sale , Weighted Average Yield, Maturities After 10 Years (in hundredths)	1.62%
Available-for-sale , Weighted Average Yield, Maturities (in hundredths)	2.28%
Available-for-sale, Full Tax-equivalent Yield, Maturities Year One (in hundredths)	1.71%
Available-for-sale, Full Tax-equivalent Yield, Maturities After 1 through 5 Years (in hundredths)	3.04%
Available-for-sale, Full Tax-equivalent Yield, Maturities After 5 through 10 years (in hundredths)	3.25%
Available-for-sale, Full Tax-equivalent Yield, Maturities After Ten Years (in hundredths)	2.32%
Available-for-sale, Full Tax-equivalent Yield, Maturities (in hundredths)	2.67%
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	298,000,000		321,000,000
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Fair Value	317,208,000		348,118,000
Less than 12 months, Unrealized Losses	(9,161,000)		(13,624,000)
12 months or longer, Fair Value	6,540,000		1,012,000
12 months or longer, Unrealized losses	(3,864,000)		(3,526,000)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	323,748,000		349,130,000
Total Unrealized Losses	(13,025,000)		(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	3,989,000
Number Of Trust Preferred Securities Sold	2
PreTSL XXVIII [Member]
Details of Trust Preferred Securities [Abstract]
Book Value	3,652,000
Market Value	241,000
Unrealized Gains (Losses)	(3,411,000)
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	133,636,000
After 1 through 5 years	34,803,000
After 5 through 10 years	0
After ten years	0
Fair Value	168,439,000		190,368,000
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Fair Value	161,367,000		183,074,000
Less than 12 months, Unrealized Losses	(5,199,000)		(7,574,000)
12 months or longer, Fair Value	0		0
12 months or longer, Unrealized losses	0		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	161,367,000		183,074,000
Total Unrealized Losses	(5,199,000)		(7,574,000)
Obligations of states and political subdivisions
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
One year or less	2,342,000
After 1 through 5 years	31,884,000
After 5 through 10 years	32,890,000
After ten years	1,985,000
Fair Value	69,101,000		64,562,000
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Fair Value	22,370,000		29,986,000
Less than 12 months, Unrealized Losses	(807,000)		(1,708,000)
12 months or longer, Fair Value	2,001,000		808,000
12 months or longer, Unrealized losses	(101,000)		(65,000)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	24,371,000		30,794,000
Total Unrealized Losses	(908,000)		(1,773,000)
Number of securities in Unrealized Loss Positions	4		2
Mortgage-backed securities: GSE residential
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
One year or less	2,696,000
After 1 through 5 years	116,555,000
After 5 through 10 years	86,809,000
After ten years	0
Fair Value	206,060,000		227,601,000
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Fair Value	129,525,000		131,125,000
Less than 12 months, Unrealized Losses	(3,101,000)		(4,275,000)
12 months or longer, Fair Value	4,298,000		13,000
12 months or longer, Unrealized losses	(352,000)		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	133,823,000		131,138,000
Total Unrealized Losses	(3,453,000)		(4,275,000)
Number of securities in Unrealized Loss Positions	2		1
Trust preferred securities
Available-for-sale Securities, Debt Maturities, Fair Value, Fiscal Year Maturity [Abstract]
One year or less	0
After 1 through 5 years	0
After 5 through 10 years	0
After ten years	241,000
Fair Value	241,000		191,000
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Fair Value	0		0
Less than 12 months, Unrealized Losses	0		0
12 months or longer, Fair Value	241,000		191,000
12 months or longer, Unrealized losses	(3,411,000)		(3,461,000)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	241,000		191,000
Total Unrealized Losses	(3,411,000)		(3,461,000)
Number of securities in Unrealized Loss Positions	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
After 1 through 5 years	0
After 5 through 10 years	3,946,000
After ten years	64,000
Fair Value	4,010,000		6,002,000
Available-for-sale Securities, Continuous Unrealized Loss Position [Abstract]
Less than 12 months, Fair Value	3,946,000		3,933,000
Less than 12 months, Unrealized Losses	(54,000)		(67,000)
12 months or longer, Fair Value	0		0
12 months or longer, Unrealized losses	0		0
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	3,946,000		3,933,000
Total Unrealized Losses	$ (54,000)		$ (67,000)