As used in this title, “insurance“ means an agreement to indemnify or otherwise assume an obligation, provide services or any other thing of value on the happening of a particular event or contingency, or to provide indemnity for loss with respect to a specified subject by specified circumstances in return for a consideration. Without limiting the generality of the term, “insurance“ shall include any business defined in section 3301 of this title, annuity contracts, and the business of health maintenance organizations and continuing care retirement communities.