Note 10 - Borrowed Funds	9 Months Ended
Sep. 30, 2015
Debt Disclosure [Abstract]
Debt Disclosure [Text Block]	10. Borrowed Funds Securities Sold Under Agreements to Repurchase. Securities sold under agreements to repurchase were $400.0 million with a weighted average rate of 3.89% at September 30, 2015, compared to $450.0 million with a weighted average rate of 3.85% at December 31, 2014. In the first nine months of 2014, the Company prepaid securities sold under agreements to repurchase totaling $100.0 million with a weighted average rate of 3.50% and incurred prepayment penalties of $3.4 million compared to no repayments in the first nine months of 2015. As of September 30, 2015, four floating-to-fixed rate agreements totaling $200.0 million with weighted average rate of 5.0% and final maturity in January 2017 have initial floating rates for one year, with floating rates of the three-month LIBOR rate minus 340 basis points. Thereafter, the rates are fixed for the remainder of the term, with interest rates ranging from 4.89% to 5.07%. As of September 30, 2015, and December 31, 2014, four fixed rate non-callable securities sold under agreements to repurchase totaled $200.0 million with a weighted average rate of 2.78%. Final maturity for the four fixed rate non-callable securities sold under agreements to repurchase is $50.0 million in August 2016, $50.0 million in July 2017, $50.0 million in June 2018, and $50.0 million in July 2018. These transactions are accounted for as collateralized financing transactions and recorded at the amounts at which the securities were sold. The Company may have to provide additional collateral for the repurchase agreements, as necessary. The underlying collateral pledged for the repurchase agreements consists of U.S. Treasury securities and mortgage-backed securities with a fair value of $439.8 million as of September 30, 2015, and $516.3 million as of December 31, 2014. Borrowing from the FHLB. As of September 30, 2015, over-night borrowings from the FHLB were zero compared to $400.0 million at a rate of 0.27% at December 31, 2014. As of September 30, 2015, the advances from the FHLB were $75.0 million at a rate of 0.87% compared to $25.0 million at a rate of 1.13% at December 31, 2014. As of September 30, 2015, FHLB advances of $50.0 million will mature in January 2017 and $25 million will mature in March 2018.

Note 10 - Borrowed Funds

9 Months Ended

Sep. 30, 2015

10. Borrowed Funds

Securities Sold Under Agreements to Repurchase. Securities sold under agreements to repurchase were $400.0 million with a weighted average rate of 3.89% at September 30, 2015, compared to $450.0 million with a weighted average rate of 3.85% at December 31, 2014. In the first nine months of 2014, the Company prepaid securities sold under agreements to repurchase totaling $100.0 million with a weighted average rate of 3.50% and incurred prepayment penalties of $3.4 million compared to no repayments in the first nine months of 2015. As of September 30, 2015, four floating-to-fixed rate agreements totaling $200.0 million with weighted average rate of 5.0% and final maturity in January 2017 have initial floating rates for one year, with floating rates of the three-month LIBOR rate minus 340 basis points. Thereafter, the rates are fixed for the remainder of the term, with interest rates ranging from 4.89% to 5.07%. As of September 30, 2015, and December 31, 2014, four fixed rate non-callable securities sold under agreements to repurchase totaled $200.0 million with a weighted average rate of 2.78%. Final maturity for the four fixed rate non-callable securities sold under agreements to repurchase is $50.0 million in August 2016, $50.0 million in July 2017, $50.0 million in June 2018, and $50.0 million in July 2018.

These transactions are accounted for as collateralized financing transactions and recorded at the amounts at which the securities were sold. The Company may have to provide additional collateral for the repurchase agreements, as necessary. The underlying collateral pledged for the repurchase agreements consists of U.S. Treasury securities and mortgage-backed securities with a fair value of $439.8 million as of September 30, 2015, and $516.3 million as of December 31, 2014.

Borrowing from the FHLB. As of September 30, 2015, over-night borrowings from the FHLB were zero compared to $400.0 million at a rate of 0.27% at December 31, 2014. As of September 30, 2015, the advances from the FHLB were $75.0 million at a rate of 0.87% compared to $25.0 million at a rate of 1.13% at December 31, 2014. As of September 30, 2015, FHLB advances of $50.0 million will mature in January 2017 and $25 million will mature in March 2018.