function twentyfourteen_post_thumbnail() {
    if ( post_password_required() || is_attachment() || ! has_post_thumbnail() ) {
      return;
    }

    if ( is_singular() ) :
      ?>

		<div class="post-thumbnail">
			<?php
      if ( ( ! is_active_sidebar( 'sidebar-2' ) || is_page_template( 'page-templates/full-width.php' ) ) ) {
        the_post_thumbnail( 'twentyfourteen-full-width' );
      } else {
        the_post_thumbnail();
      }
      ?>
		</div>

		<?php else : ?>

	<a class="post-thumbnail" href="<?php the_permalink(); ?>" aria-hidden="true">
			<?php
      if ( ( ! is_active_sidebar( 'sidebar-2' ) || is_page_template( 'page-templates/full-width.php' ) ) ) {
        the_post_thumbnail( 'twentyfourteen-full-width' );
      } else {
        the_post_thumbnail( 'post-thumbnail', array( 'alt' => get_the_title() ) );
      }
      ?>
	</a>

			<?php
  endif; // End is_singular()
  }