/**
* Category ID Column on Category Page
* https://wordpress.org/support/topic/show-category-id-on-category-page-manager-in-admin/
*/
add_filter( 'manage_edit-category_columns', 'category_column_header' );

function category_column_header($columns) {
	$columns['header_name'] = 'Header Name for Display'; 
	return $columns;
}

add_filter( 'manage_category_custom_column', 'category_column_content', 10, 3 );

function category_column_content($content, $column_name, $term_id){
	return $term_id;
}
/* Category ID Column on Category Page Ends */