Investment Securities (Details) (USD $)	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 405,914,000		$ 471,767,000
Gross Unrealized Gains	12,099,000		8,205,000
Gross Unrealized Losses	22,000		152,000
Fair/Book Value	417,991,000		479,820,000
Individual securities in continuous unrealized loss position, fair value [Abstract]
Less Than 12 Months Fair Value	7,984,000		90,077,000
12 Months or More Fair Value	0		0
Total Fair Value	7,984,000		90,077,000
Individual securities in continuous unrealized loss position, aggregate losses [Abstract]
Less Than 12 Months Unrealized Loss	22,000		152,000
12 Months or More Unrealized Loss	0		0
Total Unrealized Loss	22,000		152,000
Schedule of Held-to-maturity Securities [Line Items]
Book Value	68,392,000		63,092,000
Gross Unrealized Gains	2,308,000		2,782,000
Gross Unrealized Losses	3,000		0
Fair Value	70,697,000		65,874,000
Individual securities in continuous unrealized loss position, fair value [Abstract]
Less than Twelve Months Fair Value	528,000
Twelve Months or More Fair Value	0
Total Fair Value	528,000
Individual securities in continuous unrealized loss position, aggregate losses [Abstract]
Less than 12 Months Unrealized Loss	3,000
12 Months or Longer Unrealized Loss	0
Total Unrealized Loss	3,000
Securities Available-for-Sale [Abstract]
Within 1 Year	11,174,000
After 1 but Within 5	46,259,000
After 5 but Within 10	109,904,000
Over 10 years	250,654,000
Fair/Book Value	417,991,000		479,820,000
Held-to-maturity Securities, Debt Maturities [Abstract]
Within 1 Year	1,805,000
After 1 but Within 5	11,689,000
After 5 but Within 10	39,582,000
Over 10 years	15,316,000
Book Value	68,392,000		63,092,000
Proceeds from sales of securities available-for-sale [Abstract]
Proceeds from sales and calls of securities	55,986,000		201,135,000		268,490,000
Realized gains from sales and calls	158,000		95,000		2,895,000
Realized losses from sales and calls	0		0		0
Gain (Loss) on Investments [Line Items]
Number of investment securities held	387
Number of loss positions less than twelve months	12
Number of loss positions in twelve months or more	0
Percentage of bank qualified municipal bond portfolio rated (in hundredths)	93.00%
Percentage of portfolio not rated (in hundredths)	7.00%
Securities pledged to secure public deposits, FHLB borrowings, and other government agency deposits as required by law	296,900,000		373,200,000
Government Agency Government Sponsored Entities [Member]
Gain (Loss) on Investments [Line Items]
Unrealized losses	0		13,000
Mortgage Backed Securities [Member]
Gain (Loss) on Investments [Line Items]
Unrealized losses	10,000		139,000
Obligations of States and Political Subdivisions [Member]
Gain (Loss) on Investments [Line Items]
Unrealized losses	3,000		0
Corporate Securities [Member]
Gain (Loss) on Investments [Line Items]
Unrealized losses	12,000		0
Obligations of States and Political Subdivisions [Member]
Schedule of Held-to-maturity Securities [Line Items]
Book Value	65,694,000		59,640,000
Gross Unrealized Gains	2,296,000		2,736,000
Gross Unrealized Losses	3,000		0
Fair Value	67,987,000		62,376,000
Individual securities in continuous unrealized loss position, fair value [Abstract]
Less than Twelve Months Fair Value	528,000
Twelve Months or More Fair Value	0
Total Fair Value	528,000
Individual securities in continuous unrealized loss position, aggregate losses [Abstract]
Less than 12 Months Unrealized Loss	3,000
12 Months or Longer Unrealized Loss	0
Total Unrealized Loss	3,000
Held-to-maturity Securities, Debt Maturities [Abstract]
Book Value	65,694,000		59,640,000
Mortgage Backed Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Book Value	484,000	[1]	1,205,000	[1]
Gross Unrealized Gains	12,000	[1]	46,000	[1]
Gross Unrealized Losses	0	[1]	0	[1]
Fair Value	496,000	[1]	1,251,000	[1]
Held-to-maturity Securities, Debt Maturities [Abstract]
Book Value	484,000	[1]	1,205,000	[1]
Other [Member]
Schedule of Held-to-maturity Securities [Line Items]
Book Value	2,214,000		2,247,000
Gross Unrealized Gains	0		0
Gross Unrealized Losses	0		0
Fair Value	2,214,000		2,247,000
Held-to-maturity Securities, Debt Maturities [Abstract]
Book Value	2,214,000		2,247,000
Government Agency & Government Sponsored Entities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	26,546,000		82,195,000
Gross Unrealized Gains	277,000		413,000
Gross Unrealized Losses	0		13,000
Fair/Book Value	26,823,000		82,595,000
Individual securities in continuous unrealized loss position, fair value [Abstract]
Less Than 12 Months Fair Value			4,987,000
12 Months or More Fair Value			0
Total Fair Value			4,987,000
Individual securities in continuous unrealized loss position, aggregate losses [Abstract]
Less Than 12 Months Unrealized Loss			13,000
12 Months or More Unrealized Loss			0
Total Unrealized Loss			13,000
Securities Available-for-Sale [Abstract]
Within 1 Year	0
After 1 but Within 5	25,617,000
After 5 but Within 10	1,206,000
Over 10 years	0
Fair/Book Value	26,823,000		82,595,000
Obligations of States and Political Subdivisions [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,665,000		5,782,000
Gross Unrealized Gains	0		0
Gross Unrealized Losses	0		0
Fair/Book Value	5,665,000		5,782,000
Schedule of Held-to-maturity Securities [Line Items]
Book Value	65,694,000
Securities Available-for-Sale [Abstract]
Within 1 Year	0
After 1 but Within 5	0
After 5 but Within 10	217,000
Over 10 years	5,448,000
Fair/Book Value	5,665,000		5,782,000
Held-to-maturity Securities, Debt Maturities [Abstract]
Within 1 Year	1,805,000
After 1 but Within 5	11,200,000
After 5 but Within 10	37,373,000
Over 10 years	15,316,000
Book Value	65,694,000
Mortgage Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	341,212,000	[1]	383,380,000	[1]
Gross Unrealized Gains	11,570,000	[1]	7,792,000	[1]
Gross Unrealized Losses	10,000	[1]	139,000	[1]
Fair/Book Value	352,772,000	[1]	391,033,000	[1]
Individual securities in continuous unrealized loss position, fair value [Abstract]
Less Than 12 Months Fair Value	4,542,000		85,090,000
12 Months or More Fair Value	0		0
Total Fair Value	4,542,000		85,090,000
Individual securities in continuous unrealized loss position, aggregate losses [Abstract]
Less Than 12 Months Unrealized Loss	10,000		139,000
12 Months or More Unrealized Loss	0		0
Total Unrealized Loss	10,000		139,000
Schedule of Held-to-maturity Securities [Line Items]
Book Value	484,000
Securities Available-for-Sale [Abstract]
Within 1 Year	0
After 1 but Within 5	339,000
After 5 but Within 10	107,227,000
Over 10 years	245,206,000
Fair/Book Value	352,772,000	[1]	391,033,000	[1]
Held-to-maturity Securities, Debt Maturities [Abstract]
Within 1 Year	0
After 1 but Within 5	484,000
After 5 but Within 10	0
Over 10 years	0
Book Value	484,000
Corporate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	22,318,000
Gross Unrealized Gains	252,000
Gross Unrealized Losses	12,000
Fair/Book Value	22,558,000
Individual securities in continuous unrealized loss position, fair value [Abstract]
Less Than 12 Months Fair Value	3,442,000
12 Months or More Fair Value	0
Total Fair Value	3,442,000
Individual securities in continuous unrealized loss position, aggregate losses [Abstract]
Less Than 12 Months Unrealized Loss	12,000
12 Months or More Unrealized Loss	0
Total Unrealized Loss	12,000
Securities Available-for-Sale [Abstract]
Within 1 Year	1,001,000
After 1 but Within 5	20,303,000
After 5 but Within 10	1,254,000
Over 10 years	0
Fair/Book Value	22,558,000
Other [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	10,173,000		410,000
Gross Unrealized Gains	0		0
Gross Unrealized Losses	0		0
Fair/Book Value	10,173,000		410,000
Schedule of Held-to-maturity Securities [Line Items]
Book Value	2,214,000
Securities Available-for-Sale [Abstract]
Within 1 Year	10,173,000
After 1 but Within 5	0
After 5 but Within 10	0
Over 10 years	0
Fair/Book Value	10,173,000		410,000
Held-to-maturity Securities, Debt Maturities [Abstract]
Within 1 Year	0
After 1 but Within 5	5,000
After 5 but Within 10	2,209,000
Over 10 years	0
Book Value	$ 2,214,000

[1] All Mortgage Backed Securities were issued by an agency or government sponsored entity of the U.S. government.