Fair Values of Assets and Liabilities (Details 1) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	$ 1,157,342	$ 1,140,916
Fair Value of Investment Securities	1,159,202	1,142,776
Other investments	35,916	39,796
Loans held for sale		13,412
Other Assets	17,620	16,064
Total Assets	1,212,738	1,212,048
Other Liabilities	19,860	18,986
Total Liabilities	19,860	18,986
Obligations of U.S. Government-Sponsored Enterprises [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Fair Value of Investment Securities	845,900
Obligations of States and Political Subdivisions [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	449	459
Corporate Securities [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	11,999	11,411
Pooled Trust Preferred Collateralized Debt Obligations [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	21,792	22,980
Equity Securities [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Fair Value of Investment Securities	1,860	1,860
Mortgage Backed Securities Residential [Member] \| Obligation of U.S. Government Agencies [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	34,620	36,194
Mortgage Backed Securities Residential [Member] \| Obligations of U.S. Government-Sponsored Enterprises [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	845,739	801,031
Mortgage Backed Securities Commercial [Member] \| Obligations of U.S. Government-Sponsored Enterprises [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	177	193
Other Government Sponsored Enterprises [Member] \| Obligations of U.S. Government-Sponsored Enterprises [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	242,566	268,648
Fair Value, Inputs, Level 1 [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	0	0
Fair Value of Investment Securities	440	440
Other investments	0	0
Loans held for sale		0
Other Assets	0	0
Total Assets	440	440
Other Liabilities	0	0
Total Liabilities	0	0
Fair Value, Inputs, Level 1 [Member] \| Obligations of States and Political Subdivisions [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	0	0
Fair Value, Inputs, Level 1 [Member] \| Corporate Securities [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	0	0
Fair Value, Inputs, Level 1 [Member] \| Pooled Trust Preferred Collateralized Debt Obligations [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	0	0
Fair Value, Inputs, Level 1 [Member] \| Equity Securities [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Fair Value of Investment Securities	440	440
Fair Value, Inputs, Level 1 [Member] \| Mortgage Backed Securities Residential [Member] \| Obligation of U.S. Government Agencies [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	0	0
Fair Value, Inputs, Level 1 [Member] \| Mortgage Backed Securities Residential [Member] \| Obligations of U.S. Government-Sponsored Enterprises [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	0	0
Fair Value, Inputs, Level 1 [Member] \| Mortgage Backed Securities Commercial [Member] \| Obligations of U.S. Government-Sponsored Enterprises [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	0	0
Fair Value, Inputs, Level 1 [Member] \| Other Government Sponsored Enterprises [Member] \| Obligations of U.S. Government-Sponsored Enterprises [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	0	0
Fair Value, Inputs, Level 2 [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	1,135,550	1,117,936
Fair Value of Investment Securities	1,135,550	1,117,936
Other investments	35,916	39,796
Loans held for sale		0
Other Assets	17,620	16,064
Total Assets	1,189,086	1,173,796
Other Liabilities	19,860	18,986
Total Liabilities	19,860	18,986
Fair Value, Inputs, Level 2 [Member] \| Obligations of States and Political Subdivisions [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	449	459
Fair Value, Inputs, Level 2 [Member] \| Corporate Securities [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	11,999	11,411
Fair Value, Inputs, Level 2 [Member] \| Pooled Trust Preferred Collateralized Debt Obligations [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	0	0
Fair Value, Inputs, Level 2 [Member] \| Equity Securities [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Fair Value of Investment Securities	0	0
Fair Value, Inputs, Level 2 [Member] \| Mortgage Backed Securities Residential [Member] \| Obligation of U.S. Government Agencies [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	34,620	36,194
Fair Value, Inputs, Level 2 [Member] \| Mortgage Backed Securities Residential [Member] \| Obligations of U.S. Government-Sponsored Enterprises [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	845,739	801,031
Fair Value, Inputs, Level 2 [Member] \| Mortgage Backed Securities Commercial [Member] \| Obligations of U.S. Government-Sponsored Enterprises [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	177	193
Fair Value, Inputs, Level 2 [Member] \| Other Government Sponsored Enterprises [Member] \| Obligations of U.S. Government-Sponsored Enterprises [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	242,566	268,648
Fair Value, Inputs, Level 3 [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	21,792	22,980
Fair Value of Investment Securities	23,212	24,400
Other investments	0	0
Loans held for sale		13,412
Other Assets	0	0
Total Assets	23,212	37,812
Other Liabilities	0	0
Total Liabilities	0	0
Fair Value, Inputs, Level 3 [Member] \| Obligations of States and Political Subdivisions [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	0	0
Fair Value, Inputs, Level 3 [Member] \| Corporate Securities [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	0	0
Fair Value, Inputs, Level 3 [Member] \| Pooled Trust Preferred Collateralized Debt Obligations [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	21,792	22,980
Fair Value, Inputs, Level 3 [Member] \| Equity Securities [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Fair Value of Investment Securities	1,420	1,420
Fair Value, Inputs, Level 3 [Member] \| Mortgage Backed Securities Residential [Member] \| Obligation of U.S. Government Agencies [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	0	0
Fair Value, Inputs, Level 3 [Member] \| Mortgage Backed Securities Residential [Member] \| Obligations of U.S. Government-Sponsored Enterprises [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	0	0
Fair Value, Inputs, Level 3 [Member] \| Mortgage Backed Securities Commercial [Member] \| Obligations of U.S. Government-Sponsored Enterprises [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	0	0
Fair Value, Inputs, Level 3 [Member] \| Other Government Sponsored Enterprises [Member] \| Obligations of U.S. Government-Sponsored Enterprises [Member]
Schedule of assets and liabilities measured at fair value on recurring basis
Total Debt Securities	$ 0	$ 0

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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Federal Home Loan Bank (FHLB) stock represents an equity interest in a FHLB. It does not have a readily determinable fair value because its ownership is restricted and it lacks a market (liquidity).

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-Publisher FASB

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-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

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