Hedging Activities

3 Months Ended

Mar. 31, 2012

Hedging Activities [Abstract]

HEDGING ACTIVITIES

9. HEDGING ACTIVITIES

Our interest rate risk policy includes guidelines for measuring and monitoring interest rate risk. Within these guidelines, parameters have been established for maximum fluctuations in net interest income. Possible fluctuations are measured and monitored using net interest income simulation. Our policy provides for the use of certain derivative instruments and hedging activities to aid in managing interest rate risk to within the policy parameters.

A majority of our assets are comprised of commercial loans on which the interest rates are variable; however, the interest rates on a significant portion of these loans will likely lag an increase in market interest rates under a rising interest rate environment. As of March 31, 2012, the Mercantile Bank Prime Rate, the index on which a significant portion of our commercial floating rate loans is based, was 4.50% compared to the Wall Street Journal Prime Rate of 3.25%. Historically, the two indices have been equal; however, we elected not to reduce the Mercantile Bank Prime Rate in late October and mid-December of 2008 when the Wall Street Journal Prime Rate declined by 50 and 75 basis points, respectively. It is our general intent to keep the Mercantile Bank Prime Rate unchanged until the Wall Street Journal Prime Rate equals the Mercantile Bank Prime Rate, at which time the two indices will likely remain equal in future periods. In addition, a majority of our floating rate loans, whether tied to the Mercantile Bank Prime Rate, Wall Street Journal Prime Rate or Libor rates, have interest rate floors that are currently higher than the indexed rate provides for. To help mitigate the negative impact to our net interest income in an increasing interest rate environment resulting from our cost of funds likely increasing at a higher rate than the yield on our assets, we may periodically enter into derivative financial instruments.

In June 2011, we simultaneously purchased and sold an interest rate cap with a correspondent bank, a structure commonly referred to as a “cap corridor.” The cap corridor, which does not qualify for hedge accounting, consisted of us purchasing a $100 million interest rate cap with a strike rate in close proximity to the then-current 30-Day Libor rate and selling a $100 million interest rate cap with a strike rate that is 125 basis points higher than the purchased interest rate cap strike rate. On the settlement date, the present value of the purchased interest rate cap was recorded as an asset, while the present value of the sold interest rate cap was recorded as a liability. At each month end, the recorded balances of the purchased and sold interest rate caps are adjusted to reflect the current present values, with the offsetting entry being recorded to interest income on commercial loans. We recorded a net decrease of $0.2 million during the first quarter of 2012 to interest income on commercial loans to reflect the net change in present values. Payments made or received under the purchased and sold interest rate cap contracts, if any, are also recorded to interest income on commercial loans. No such payments were made or received during the first quarter of 2012.

In February 2012, we entered into an interest rate swap agreement with a correspondent bank to hedge the floating rate on our trust preferred securities. Our $32.0 million of trust preferred securities have a rate equal to 90-Day Libor Rate plus a fixed spread of 218 basis points, and are subject to repricing quarterly. The interest rate swap agreement provides for us to pay our correspondent bank a fixed rate, while our correspondent bank will pay us the 90-Day Libor Rate on a $32.0 million notional amount. The quarterly re-set dates for the floating rate on the interest rate swap agreement are the same as the re-set dates for the floating rate on the trust preferred securities. While the trade date of the interest rate swap agreement was in February 2012, the effective date is not until January 2013, with a maturity date of January 2018. The interest rate swap agreement does qualify for hedge accounting; therefore, monthly fluctuations in the present value of the interest rate swap agreement, net of tax effect, are recorded to other comprehensive income (loss). As of March 31, 2012, the present value of the interest rate swap agreement, which is recorded as an asset, equaled $0.1 million. The present value of the interest rate swap agreement on the trade date was $0.