Fair Value Measurements and Fair Value of Financial Instruments (Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	$ 467,190	$ 414,507
Estimate of Fair Value, Fair Value Disclosure [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	467,190	414,507
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	12,112	10,546
Significant Other Observable Inputs (Level 2) [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	453,222	401,846
Significant Unobservable Inputs (Level 3) [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	1,856	2,115
Federal agency obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	18,683	24,969
Federal agency obligations [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	18,683
Assets, Fair Value Disclosure, Recurring		24,969
Federal agency obligations [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring		2,004
Federal agency obligations [Member] | Significant Other Observable Inputs (Level 2) [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	18,683
Assets, Fair Value Disclosure, Recurring		22,965
Residential mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	88,794	115,364
Residential mortgage-backed securities [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	88,794
Assets, Fair Value Disclosure, Recurring		115,364
Residential mortgage-backed securities [Member] | Significant Other Observable Inputs (Level 2) [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	88,794
Assets, Fair Value Disclosure, Recurring		115,364
Commercial mortgage-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	9,799
Commercial mortgage-backed securities [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	9,799
Assets, Fair Value Disclosure, Recurring		1,899
Commercial mortgage-backed securities [Member] | Significant Other Observable Inputs (Level 2) [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	9,799
Commercial mortgage-backed securities [Member] | Significant Unobservable Inputs (Level 3) [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring		1,899
Obligations of U.S. states and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	85,144	69,173
Obligations of U.S. states and political subdivisions [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	85,144
Assets, Fair Value Disclosure, Recurring		69,173
Obligations of U.S. states and political subdivisions [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	256
Assets, Fair Value Disclosure, Recurring		397
Obligations of U.S. states and political subdivisions [Member] | Significant Other Observable Inputs (Level 2) [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	84,888
Assets, Fair Value Disclosure, Recurring		68,776
Trust preferred securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	18,825	16,187
Trust preferred securities [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	18,825
Assets, Fair Value Disclosure, Recurring		16,187
Trust preferred securities [Member] | Significant Other Observable Inputs (Level 2) [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	18,721
Assets, Fair Value Disclosure, Recurring		15,971
Trust preferred securities [Member] | Significant Unobservable Inputs (Level 3) [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	104
Assets, Fair Value Disclosure, Recurring		216
Corporate bonds and notes [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	212,704	173,117
Corporate bonds and notes [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	212,704
Assets, Fair Value Disclosure, Recurring		173,117
Corporate bonds and notes [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, Fair Value Disclosure, Recurring		2,000
Corporate bonds and notes [Member] | Significant Other Observable Inputs (Level 2) [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	212,704
Assets, Fair Value Disclosure, Recurring		171,117
Collateralized mortgage obligations [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	1,752	1,899
Collateralized mortgage obligations [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	1,752
Collateralized mortgage obligations [Member] | Significant Unobservable Inputs (Level 3) [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	1,752
Asset-backed securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	19,633	7,653
Asset-backed securities [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	19,633
Assets, Fair Value Disclosure, Recurring		7,653
Asset-backed securities [Member] | Significant Other Observable Inputs (Level 2) [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	19,633
Assets, Fair Value Disclosure, Recurring		7,653
Equity securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	601	262
Equity securities [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	601
Assets, Fair Value Disclosure, Recurring		262
Equity securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	601
Assets, Fair Value Disclosure, Recurring		262
Other securities [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	11,255	5,883
Other securities [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	11,255
Other securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Assets Measured at Fair Value on a Recurring Basis [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available-for-sale Securities	$ 11,255