Cincinnati Financial Corp. CINF reported first-quarter 2016 operating income of 89 cents per share, which comfortably surpassed the Zacks Consensus Estimate of 77 cents by 15.6%. The bottom line also soared 50.8% year over year. The stellar performance was backed by solid underwriting results and higher investment income. Including lower net realized investment loss of 24 cents per share, the company reported net income surged 46.8% year over year to $1.13 per share.Behind the HeadlinesTotal operating revenue in the reported quarter grossed $1.36 billion, up 6.1% year over year. The top-line improvement was driven by higher premiums earned (up 5.5%) and increased investment income (up 4.3%).Total benefits and expenses of Cincinnati Financial dipped 1.1% year over year to $1.09 billion, primarily due to lower insurance losses and contract holders’ benefits.Combined ratio – a measure of underwriting profitability – improved 610 basis points (bps) year over year to 91.4%.Cincinnati Financial had 1,551 agency relationships as of Mar 31, 2016 compared with 1,526 as of Dec 31, 2015.Quarterly Segment UpdateCommercial Lines Insurance: Total revenue of $761 million grew 3.7% year over year driven by an increase in premiums earned. Underwriting profit soared 92.3% year over year to $50 million. Combined ratio improved 300 bps year over year to 93.6%.Personal Lines Insurance: Total revenue of $284 million jumped 5.6% year over year. Premiums earned increased 5.6% year over year to $283 million on higher renewal written premiums and growth in new business. Supported by lower loss and loss expenses, the segment posted underwriting profit of $28 million, rebounding from year ago loss of $3 million. As a result, combined ratio improved 1130 bps year over year to 90.1%.Excess and Surplus Lines Insurance: Premiums earned increased 7.5% year over year. The segment also witnessed a massive year-over-year growth of 325% in underwriting profit to $17 million. Combined ratio improved 2720 bps year over year to 61.1%.Life Insurance: Total revenue grew 7.7% year over year to 98 million due to year-over-year increase of 9.4% in earned premiums. Total benefits and expenses rose 5.1% year over year to $82 million.Financial UpdateAs of Mar 31, 2016, Cincinnati Financial had assets worth $19.45 billion, up 3% from the 2015-end level.Cincinnati Financial’s debt-to-capital ratio was 10.9% as of Mar 31, 2016. This reflects an improvement from 11.3% at the end of 2015.As of Mar 31, 2016, Cincinnati Financial’s book value per share was $40.96, up 4.5% from that of Dec 31, 2015.Zacks Rank and Performance of Other P&C InsurersCincinnati Financial currently carries a Zacks Rank #3 (Hold). Some other P&C insurers too recently released their first-quarter earnings results. While the bottom line at RLI Corp. RLI and First American Financial Corporation FAF beat their respective Zacks Consensus Estimates, Progressive Corp. PGR missed the same in the first quarter.Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report >>Want the latest recommendations from Zacks Investment Research? Today, you can download 7 Best Stocks for the Next 30 Days. Click to get this free report RLI CORP (RLI): Free Stock Analysis Report CINCINNATI FINL (CINF): Free Stock Analysis Report PROGRESSIVE COR (PGR): Free Stock Analysis Report FIRST AMER FINL (FAF): Free Stock Analysis Report To read this article on Zacks.com click here. Zacks Investment Research