Securities (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended			9 Months Ended		3 Months Ended	9 Months Ended		3 Months Ended					9 Months Ended		3 Months Ended	9 Months Ended	3 Months Ended	9 Months Ended	1 Months Ended
	Sep. 30, 2012	Sep. 30, 2011 Securities	Sep. 30, 2012 Types_Of_Securities	Sep. 30, 2011	Dec. 31, 2011	Sep. 30, 2012 Collateralized mortgage obligations [Member]	Sep. 30, 2012 Mortgage Backed Securities, Other [Member] Securities	Sep. 30, 2012 Agency CMOs [Member] Securities	Sep. 30, 2011 Agency CMOs [Member] Securities	Dec. 31, 2011 Agency CMOs [Member]	Sep. 30, 2012 Private-label CMOs [Member] Securities	Sep. 30, 2012 Private-label CMOs [Member] Private-label_CMO_Securities	Sep. 30, 2012 Government Agency Debentures [Member] Securities	Sep. 30, 2012 Corporate debentures [Member] Corporate_Debentures	Dec. 31, 2011 Corporate debentures [Member]	Sep. 30, 2012 Government Agency Sponsored MBS/CMOs [Member] Government_Agency_Sponsored_MBS-CMOs	Sep. 30, 2012 Investment-Grade Corporate Bonds [Member] Investment-grade_Corporate_Bonds	Sep. 30, 2012 Bonds [Member] Bonds	Sep. 30, 2011 Not Classified as Available for Sale [Member] Agency CMOs [Member] Securities	Sep. 30, 2012 No Losses Attributable to Credit [Member] Private-label CMOs [Member] Private-label_CMO_Securities	Sep. 30, 2012 Losses Attributable to Credit [Member] Private-label CMOs [Member] Corporate_Debentures	Oct. 31, 2012 Sale of Available for Sale Securities [Member] Private-label CMOs [Member]
Investment Securities [Line Items]
Number of securities sold		1					4	27	13		7	2						5	1	1
Proceeds from sale of available-for-sale securities	$ 3,200,000	$ 852,000	$ 252,563,000	$ 125,299,000		$ 257,400,000			$ 126,200,000
Gross realized gains on available-for-sale securities		7,000	959,000						350,000			5,000
Investment securities, value called by issuing agency			160,300,000										25,000,000	5,000,000
Held to maturity securities, ratio of remaining par value to original purchases par value		15.00%	15.00%
Number of securities, type			2										11	1		3	4				1
Amortized cost, available-for-sale securities									125,800,000
Securities pledged to secure public deposits and other	644,500,000		644,500,000
Realized loss on available for sale securities	37,000											42,000
Other than temporary impairment loss on available-for-sale securities																					140,000
Available-for-sale securities, amortized cost basis	608,145,000		608,145,000		607,680,000			500,268,000		519,167,000	2,500,000	2,500,000		14,958,000	19,952,000
Available-for-sale securities, fair value	619,410,000		619,410,000					509,025,000			2,500,000	2,500,000
Realized pre-tax gain on sale of available-for-sale securities																						$ 23,000