Occidental Petroleum Corporation (NYSE:OXY) reported mixed first-quarter financial results after the bell Tuesday. Here's a look at the details.  The Details: Occidental Petroleum reported quarterly earnings of 63 cents per share which beat the analyst consensus estimate of 60 cents by 5% and represents a 42.2% decrease year-over-year. Quarterly sales came in at $6.01 billion, missing the analyst consensus estimate of $6.7 billion by 10.3% and representing a 17.19% decrease from sales of $7.26 ...