Yesterday, we posted our earnings press release, financial supplement, and investor presentation on the Investors section of selective.com. These milestones reflect our long-term commitment to disciplined growth and operational excellence. We delivered a 13.7% operating ROE led by excellent investment income, which grew 18% year-over-year. Each insurance segment produced an underwriting profit, and our 98% combined ratio improved 2.2 points from a year ago.
Driving margin improvement in Standard Commercial Lines, our largest segment, remains a key area of focus. This is exactly the portfolio effect we intended, as we believe these actions improve the earnings power of the portfolio over time. We are constraining growth where margins do not meet our targets focusing new business and retention strategies on the business that continues to enhance the earning power of the book. With our strong margins, 50-state footprint, and expansion of our distribution channel to include our retail agents, we believe E&S continues to present a long-term opportunity to support our profitable growth and diversification objectives.
Year to date, the combined ratio of 94.1 was 80 basis points better than the first six months of 2025 and compared favorably to the 100.6 combined ratio for the full year of 2025. We are focused on growth in our target market where we believe our rates are adequate. Diversifying revenue and income within and across our three insurance segments and further leveraging data, analytics and technology, including artificial intelligence, to drive operational efficiency and improve underwriting and claim outcomes. For the quarter, we reported fully diluted EPS of $2.11 and non-GAAP operating EPS of $1.95, resulting in a 14.8% ROE and a 13.7% operating ROE.