Get All IDs of Custom Post Type

This could be of help: http://codex.wordpress.org/Function_Reference/wp_count_posts

OR this…

$qry_args = array(
		'post_status' => 'publish', // optional
		'post_type' => 'your_post_type', // Change to match your post_type
		'posts_per_page' => -1, // ALL posts
		);

	$all_posts = new WP_Query( $qry_args );
        echo "Total matching posts: $all_posts->found_posts";