Investment Securities Schedule of Held to Maturity Securities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Schedule of Held-to-maturity Securities [Line Items]
Held-to-Maturity Securities	$ 239,803	$ 150,688
Held-to-maturity Securities, at Fair Value	248,252	159,059
Gross Unrealized Gains	8,512	8,378
Gross Unrealized Losses	63	7
Held-to-maturity Securities, Pledged as Collateral	238,803	149,688
Maturities of Debt Securities, at Amortized Cost [Abstract]
Within One Year	32,047
From 1 - 5 Years	124,861
From 5 - 10 Years	76,096
Over 10 Years	6,799
Maturities of Debt Securities, at Fair Value [Abstract]
Within One Year	32,115
From 1 - 5 Years	126,427
From 5 - 10 Years	82,476
Over 10 Years	7,234
Securities in a Continuous Loss Position, at Fair Value [Abstract]
Less than 12 Months	21,583	510
12 Months or Longer	503	0
Total	22,086	510
Number of Securities in a Continuous Loss Position	61	1
Unrealized Losses on Securities in a Continuous Loss Position [Abstract]
Less than 12 Months	62	7
12 Months or Longer	1	0
Total	63	7
Available-For-Sale Securities, at Fair Value	478,698	556,538
State and Municipal Obligations [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-Maturity Securities	183,373	149,688
Held-to-maturity Securities, at Fair Value	191,196	158,059
Gross Unrealized Gains	7,886	8,378
Gross Unrealized Losses	63	7
Maturities of Debt Securities, at Amortized Cost [Abstract]
Within One Year	32,047
From 1 - 5 Years	69,431
From 5 - 10 Years	76,096
Over 10 Years	5,799
Maturities of Debt Securities, at Fair Value [Abstract]
Within One Year	32,115
From 1 - 5 Years	70,371
From 5 - 10 Years	82,476
Over 10 Years	6,234
Securities in a Continuous Loss Position, at Fair Value [Abstract]
Less than 12 Months	21,583	510
12 Months or Longer	503	0
Total	22,086	510
Number of Securities in a Continuous Loss Position	61	1
Unrealized Losses on Securities in a Continuous Loss Position [Abstract]
Less than 12 Months	62	7
12 Months or Longer	1	0
Total	63	7
Mortgage-Backed Securities - Residential [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-Maturity Securities	55,430	0
Held-to-maturity Securities, at Fair Value	56,056	0
Gross Unrealized Gains	626	0
Gross Unrealized Losses	0	0
Maturities of Debt Securities, at Amortized Cost [Abstract]
Within One Year	0
From 1 - 5 Years	55,430
From 5 - 10 Years	0
Over 10 Years	0
Maturities of Debt Securities, at Fair Value [Abstract]
Within One Year	0
From 1 - 5 Years	56,056
From 5 - 10 Years	0
Over 10 Years	0
Securities in a Continuous Loss Position, at Fair Value [Abstract]
Less than 12 Months	0	0
12 Months or Longer	0	0
Total	0	0
Number of Securities in a Continuous Loss Position	0	0
Unrealized Losses on Securities in a Continuous Loss Position [Abstract]
Less than 12 Months	0	0
12 Months or Longer	0	0
Total	0	0
Mortgage-Backed Securities - Residential [Member] | US Government-sponsored Enterprises Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-Maturity Securities	55,400
Held-to-maturity Securities, at Fair Value	56,100
Corporate and Other Debt Securities [Member]
Schedule of Held-to-maturity Securities [Line Items]
Held-to-Maturity Securities	1,000	1,000
Held-to-maturity Securities, at Fair Value	1,000	1,000
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Maturities of Debt Securities, at Amortized Cost [Abstract]
Within One Year	0
From 1 - 5 Years	0
From 5 - 10 Years	0
Over 10 Years	1,000
Maturities of Debt Securities, at Fair Value [Abstract]
Within One Year	0
From 1 - 5 Years	0
From 5 - 10 Years	0
Over 10 Years	1,000
Securities in a Continuous Loss Position, at Fair Value [Abstract]
Less than 12 Months	0	0
12 Months or Longer	0	0
Total	0	0
Number of Securities in a Continuous Loss Position	0	0
Unrealized Losses on Securities in a Continuous Loss Position [Abstract]
Less than 12 Months	0	0
12 Months or Longer	0	0
Total	$ 0	$ 0