Investment Securities (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	$ 277,072	$ 246,158
Unrealized gains	8,210	8,041
Unrealized losses	141	193
Fair value	285,141	254,006
Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than Twelve Months, Fair Value	29,152
Twelve Months or Greater, Fair Value	2,348
Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 Months, Unrealized Losses	110
12 Months or Longer, Unrealized Losses	31
US Treasury Notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	20,848	17,385
Unrealized gains	321	165
Unrealized losses	0	0
Fair value	21,169	17,550
Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than Twelve Months, Fair Value	0
Twelve Months or Greater, Fair Value	0
Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 Months, Unrealized Losses	0
12 Months or Longer, Unrealized Losses	0
US Agency Notes [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	99,700	81,415
Unrealized gains	1,577	1,517
Unrealized losses	35	5
Fair value	101,242	82,927
Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than Twelve Months, Fair Value	16,819
Twelve Months or Greater, Fair Value	0
Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 Months, Unrealized Losses	35
12 Months or Longer, Unrealized Losses	0
US Agency Mortgage-Backed Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	56,814	50,923
Unrealized gains	1,498	1,475
Unrealized losses	15	111
Fair value	58,297	52,287
Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than Twelve Months, Fair Value	4,355
Twelve Months or Greater, Fair Value	0
Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 Months, Unrealized Losses	15
12 Months or Longer, Unrealized Losses	0
Non-Taxable [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	69,854	65,896
Unrealized gains	3,427	3,827
Unrealized losses	48	20
Fair value	73,233	69,703
Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than Twelve Months, Fair Value	5,272
Twelve Months or Greater, Fair Value	2,148
Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 Months, Unrealized Losses	30
12 Months or Longer, Unrealized Losses	18
Taxable [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	19,983	21,027
Unrealized gains	1,195	894
Unrealized losses	0	14
Fair value	21,178	21,907
Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than Twelve Months, Fair Value	0
Twelve Months or Greater, Fair Value	0
Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 Months, Unrealized Losses	0
12 Months or Longer, Unrealized Losses	0
Mutual Funds [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	2,118	2,103
Unrealized gains	35	22
Unrealized losses	0	0
Fair value	2,153	2,125
Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than Twelve Months, Fair Value	0
Twelve Months or Greater, Fair Value	0
Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 Months, Unrealized Losses	0
12 Months or Longer, Unrealized Losses	0
Trust Preferred Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	498	549
Unrealized gains	26	37
Unrealized losses	9	22
Fair value	515	564
Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than Twelve Months, Fair Value	99
Twelve Months or Greater, Fair Value	141
Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 Months, Unrealized Losses	1
12 Months or Longer, Unrealized Losses	8
Corporate Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	6,280	6,334
Unrealized gains	53	47
Unrealized losses	1	16
Fair value	6,332	6,365
Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than Twelve Months, Fair Value	2,192
Twelve Months or Greater, Fair Value	0
Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 Months, Unrealized Losses	1
12 Months or Longer, Unrealized Losses	0
Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized cost	977	526
Unrealized gains	78	57
Unrealized losses	33	5
Fair value	1,022	578
Continuous Unrealized Loss Position, Fair Value [Abstract]
Less than Twelve Months, Fair Value	415
Twelve Months or Greater, Fair Value	59
Continuous Unrealized Loss Position, Unrealized Losses [Abstract]
Less than 12 Months, Unrealized Losses	28
12 Months or Longer, Unrealized Losses	$ 5