This may not be as simple and clear cut as previous posters have suggested. It is important to know where you purchased the ticket, for what routing and why do you need to cancel?

For exceptional circumstances like death of one of the passengers or a close family member, A3 is always very flexible, especially if you have status. Also, if you purchased the ticket in the USA there are often special conditions for receiving a voucher or flight-credit up to the amount of the original ticket. Additionally, if none of those special conditions can be applied, then consider changing the ticket for a future date rather than cancelling. Non-refundable does not automatically mean non-changeable and changing for a future date more convenient may well be more effective than cancelling and buying another ticket later.