 The company is based in Dallas, Texas with offices in Fort Worth, Austin, Houston, San Antonio, Phoenix and Denver.In 2013 the company was included in Fortune magazine's list of the "100 Best Places to Work in America".It has been on the list since the it was first published in 1998, and in 2005 was included in Fortune's "100 Best Hall of Fame," a list of 22 companies in the U.S. who have appeared on the list every year.