Add Post and Page ID Column

<?php
if ( ! function_exists( 'scseed_add_id_column' ) ) {
    function scseed_add_id_column( $columns ) {
        $columns['scseed_item_id'] = 'ID';
        return $columns;
    }
}
if ( ! function_exists( 'scseed_show_id_column' ) ) {
    function scseed_show_id_column( $column, $post_id ) {
        if ( 'scseed_item_id' === $column ) {
            echo esc_html( $post_id );
        }
    }
}
add_filter( 'manage_posts_columns', 'scseed_add_id_column' );
add_filter( 'manage_pages_columns', 'scseed_add_id_column' );
add_action( 'manage_posts_custom_column', 'scseed_show_id_column', 10, 2 );
add_action( 'manage_pages_custom_column', 'scseed_show_id_column', 10, 2 );