The company reported earnings after the market closed. Its income more than doubled as higher sales and prices offset increasing prices for raw materials, the company reported. Alcoa earned 32 cents per share. Analysts expected the company to earn 33 cents per share, according to FactSet. The company reaffirmed its forecast for 12 percent growth in global aluminum demand this year. Alcoa was down 0.4 percent in early aftermarket trading.