Jefferies Financial Group Inc. (NYSE:JEF) reported its first-quarter financial results after the bell Wednesday. Here’s a look at the highlights. The Details: The company reported quarterly earnings of 87 cents per share which beat the analyst consensus estimate of 75 cents by 16% and was a 58.18% increase over earnings of 55 cents per share from the same period last year. Quarterly sales came in at $1.74 billion, beating the analyst consensus estimate of $1.52 billion by 14.36% and represented a 35.48% increase year-over-year. Investment Banking net revenues for the quarter were $740 million,…