SQL - Stored Procedure with Select Statement using IN (@Variable_CommaDelimitedListOfIDS)

Question

I am creating a stored procedure to which I want to pass as variable a comma delimited list of Ids. I want to use the Ids into a select statement, something like:

Answer 1

CREATE PROCEDURE PROCEDURENAME
@Id Numeric(18,0)
AS
BEGIN
    SELECT * FROM tableName
    WHERE tableName.Id IN (@Id)
END