The insurance industry is massive and extends around the world. Major public and private companies are involved in the transfer of risk business as their main business or as an adjunct to their main business. Best known US corporations are Berkshire Hathaway, Traveler's Corp and MetLife. The most notorious (and formerly the biggest in the world) is AIG, who have made a name for themselves by derivates fraud. In Britain, Lloyd's and Barclay's are both big insurers.
Insurance as an industry tends to do well when the economy is already expanding and as it hits its top. This is because onyl after people have been making money are they concerned with insuring their situation. In hard times it is seen as a disposable luxury.