Cincinnati Financial Corp.Another mid-cap insurer that made this week's list is Cincinnati Financial ( CINF), a property-casualty insurance firm. Because Cincinnati Financial caters primarily to smaller commercial clients through independent agents, the firm is able to make the most of personal relationships that agents have built. That's the main reason why agents are at the center of the firm's expansion plan -- keep your agents happy and sales will follow. That mantra has played out incredibly well in the last few years; at present, Cincinnati Financial provides the lion's share of insurance coverage for most of its agencies. One potential tripping point for Cincinnati Financial is the firm's regional exposure to the Midwest. While a relatively limited geographic footprint suggests that there's still a lot of room for growth, it also means that the impact of casualty risks are magnified in CINF's home base. To combat that risk, management has been pairing an ambitious growth plan with a conservative balance sheet - a winning combination, in my view. The firm's 0.63% dividend increase may be one of the smallest from the last two weeks, but Cincinnati Financial's overall yield is one of the biggest. At present, the company's dividend yield weighs in at 5.87%, making this stock a solid option for investors in search of a core holding for their income portfolios.