AFS Securities (Amortized cost and fair value of AFS securities by contractual maturity) (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Maturing, Due in One Year or Less	$ 16,838
Maturing, After One Year But Within Five Years	61,118
Maturing, After Five Years But Within Ten Years	113,612
Maturing, After Ten Years	50,272
Securities With Variable Monthly Payments or Noncontractual Maturities	330,247
Amortized Cost	572,087	517,614
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Maturing, Due in One Year or Less, Fair value	16,883
Maturing, After One Year But Within Five Years, Fair value	63,150
Maturing, After Five Years But Within Ten Years, Fair value	116,389
Maturing, After Ten Years, Fair value	51,040
Securities With Variable Monthly Payments or Noncontractual Maturities, Fair value	327,618
Total, Fair value	575,080	512,062
Government sponsored enterprises [Member]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Maturing, Due in One Year or Less	0
Maturing, After One Year But Within Five Years	9,068
Maturing, After Five Years But Within Ten Years	15,577
Maturing, After Ten Years	0
Securities With Variable Monthly Payments or Noncontractual Maturities	0
Amortized Cost	24,645	24,860
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Total, Fair value	23,917	23,745
States and political subdivisions [Member]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Maturing, Due in One Year or Less	16,838
Maturing, After One Year But Within Five Years	52,050
Maturing, After Five Years But Within Ten Years	98,035
Maturing, After Ten Years	50,272
Securities With Variable Monthly Payments or Noncontractual Maturities	0
Amortized Cost	217,195	200,323
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Total, Fair value	223,545	201,988
Auction rate money market preferred [Member]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Maturing, Due in One Year or Less	0
Maturing, After One Year But Within Five Years	0
Maturing, After Five Years But Within Ten Years	0
Maturing, After Ten Years	0
Securities With Variable Monthly Payments or Noncontractual Maturities	3,200
Amortized Cost	3,200	3,200
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Total, Fair value	2,863	2,577
Preferred stocks [Member]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Securities With Variable Monthly Payments or Noncontractual Maturities	6,800
Amortized Cost	6,800	6,800
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Total, Fair value	6,173	5,827
Mortgage-backed securities [Member]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Maturing, Due in One Year or Less	0
Maturing, After One Year But Within Five Years	0
Maturing, After Five Years But Within Ten Years	0
Maturing, After Ten Years	0
Securities With Variable Monthly Payments or Noncontractual Maturities	171,856
Amortized Cost	171,856	147,292
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Total, Fair value	170,767	144,115
Collateralized mortgage obligations [Member]
Available-for-sale Securities, Debt Maturities, Amortized Cost Basis, Rolling Maturity [Abstract]
Maturing, Due in One Year or Less	0
Maturing, After One Year But Within Five Years	0
Maturing, After Five Years But Within Ten Years	0
Maturing, After Ten Years	0
Securities With Variable Monthly Payments or Noncontractual Maturities	148,391
Amortized Cost	148,391	135,139
Available-for-sale Securities, Debt Maturities, Fair Value, Rolling Maturity [Abstract]
Total, Fair value	$ 147,815	$ 133,810