Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE Customer_Policies (customer_id VARCHAR)
TABLE: CREATE TABLE Customers (customer_details VARCHAR, customer_id VARCHAR)
TABLE: CREATE TABLE Customers (customer_details VARCHAR)

### Question ###
List the details of the customers who do not have any policies.

### Accurate SQL ###

SELECT customer_details FROM Customers EXCEPT SELECT T1.customer_details FROM Customers AS T1 JOIN Customer_Policies AS T2 ON T1.customer_id = T2.customer_id