"Berkshire Hathaway is a holding company. Through its subsidiaries, Berkshire Hathaway engages in a number of business activities, including: property and casualty insurance and reinsurance; railroad, which operate railroad systems in North America through BNSF Railway Company; utilities and energy, particularly regulated electric and gas utility, including power generation and distribution activities; finance, which include proprietary investing, manufactured housing and related consumer financing, transportation equipment leasing and furniture leasing; and manufacturing, service and retailing businesses including wholesale distribution and logistics services, and manufacturers of clothing and footwear."
~ From Mergent Online, Jan. 18, 2013
Shareholder letters: 2011, 2010, 2009, 2008, 2007, more