2015 U.S. Community Bank and Credit Union Rankings

This year, the rankings were divided into 3 categories: banks with assets between $1 billion and $10 billion, banks with less than $1 billion in assets, and all credit unions.

Woburn, Mass.-based Northern Bancorp Inc. took the top spot in S&P Global Market Intelligence's ranking of best-performing community banks between $1 billion and $10 billion in assets. Founded in 1960 as Woburn Bank & Trust Co., Northern Bancorp unit Northern Bank & Trust Co. now has 13 brick-and-mortar branches in Massachusetts.  It has also more than doubled in size since 2010, ending 2015 with $1.41 billion in assets. 

View the 100 best-performing banks with assets between $1 billion and $10 billion.

Almena State Bank topped the S&P Global Market Intelligence ranking of the best-performing community banks with less than $1 billion in assets in 2015. There's no place like home for this Kansas-based bank, which has remained at its original location on Main Street in Almena since being chartered in 1934. Almena opened its second branch in Norton County in 1995, and added a third branch through its acquisition of Atwood, Kan.-based Farmers State Bank in mid-2015.

View the 100 best-performing banks with less than $1 billion in assets.

Idaho Central Credit Union was the best-performing credit union in the U.S. for the fourth consecutive year and improved in multiple metrics in 2015. The Chubbuck, Idaho-based credit union's ratio of net charge-offs to average loans dipped 5 basis points to 0.09%, while its efficiency ratio dropped 9.17 percentage points to 61.45%. Idaho Central saw market growth of 21.67%, compared to 19.15% in 2014. The credit union's assets grew by 30.50% to $2.42 billion in 2015, making it the 75th-largest credit union by assets as of Dec. 31, 2015.

View the 50 best-peforming credit unions.

To rank community banks, S&P Global Market Intelligence looked at commercial banks with 60 or fewer offices, and loan portfolios accounting for more than one-third of total assets. To be eligible for the ranking, a bank's loan portfolio had to consist of less than 50% credit card loans, and no more than half of its revenue could be from nontraditional banking activities. Banks also had to be well capitalized according to 2015 regulatory standards. Banks with a parent company with more than $1 billion in assets were excluded.

S&P Global Market Intelligence ranked the nation's credit unions using five core financial performance metrics: member growth, net charge-offs as a percentage of average loans, efficiency ratio, asset quality and market growth. To be eligible for the ranking, a credit union had to report more than $500 million in total assets and a net worth ratio of at least 7.0% as of Dec. 31, 2015.