Let λ be a symmetric, normal sequence space equipped with a k-symmetric, monotone norm ‖.‖λ. Also, assume that (λ, ‖.‖λ) is AK-BK. Corresponding to this sequence space λ, we study compactness of the operator ideal K
λ. We proved compactness, completeness and injectivity of the dual operator ideal K
. We also investigate the factorization of these operators.