diff --git a/core/core.libraries.yml b/core/core.libraries.yml
index 13c19005ce..0b3b12855f 100644
--- a/core/core.libraries.yml
+++ b/core/core.libraries.yml
@@ -122,7 +122,7 @@ drupal.checkbox:
 drupal.collapse:
   version: VERSION
   js:
-    misc/details.js: {}
+    misc/details-content-synopsis.js: {}
     misc/details-aria.js: {}
     misc/collapse.js: {}
   dependencies:
diff --git a/core/misc/details-content-synopsis.es6.js b/core/misc/details-content-synopsis.es6.js
new file mode 100644
index 0000000000..b724a279e0
--- /dev/null
+++ b/core/misc/details-content-synopsis.es6.js
@@ -0,0 +1,104 @@
+/**
+ * @file
+ * Adds a synopsis of a details element's contents to its summary.
+ */
+(($, Drupal) => {
+  /**
+   * The DetailsContentSynopsis object represents a single details element.
+   *
+   * @constructor Drupal.DetailsContentSynopsis
+   *
+   * @param {HTMLElement} node
+   *   A details element, the summary of which may have supplemental text.
+   *   The supplemental text is a synopsis of the details element's contents.
+   */
+  function DetailsContentSynopsis(node) {
+    this.$node = $(node);
+    this.setupSummary();
+  }
+
+  $.extend(
+    DetailsContentSynopsis,
+    /** @lends Drupal.DetailsContentSynopsis */ {
+      /**
+       * Holds references to instantiated DetailsContentSynopsis objects.
+       *
+       * @type {Array.<Drupal.DetailsContentSynopsis>}
+       */
+      instances: [],
+    },
+  );
+
+  $.extend(
+    DetailsContentSynopsis.prototype,
+    /** @lends Drupal.DetailsContentSynopsis# */ {
+      /**
+       * Initialize and setup summary events and markup.
+       *
+       * @fires event:summaryUpdated
+       *
+       * @listens event:summaryUpdated
+       */
+      setupSummary() {
+        this.$synopsizedDetailsContentWrapper = $(
+          Drupal.theme('synopsizedDetailsContentWrapper'),
+        );
+        this.$node
+          .on('summaryUpdated', $.proxy(this.onSummaryUpdated, this))
+          .trigger('summaryUpdated')
+          .find('> summary')
+          .append(this.$synopsizedDetailsContentWrapper);
+      },
+
+      /**
+       * Update summary.
+       */
+      onSummaryUpdated() {
+        const text = $.trim(this.$node.drupalGetSummary());
+        this.$synopsizedDetailsContentWrapper.html(
+          Drupal.theme('synopsizedDetailsContent', text),
+        );
+      },
+    },
+  );
+
+  /**
+   * Adds a synopsis of a details element's contents to its summary.
+   *
+   * @type {Drupal~behavior}
+   *
+   * @prop {Drupal~behaviorAttach} attach
+   *   Attaches behavior for the details element.
+   */
+  Drupal.behaviors.detailsSummary = {
+    attach(context) {
+      const $detailsElements = $(context)
+        .find('details')
+        .once('details');
+      $detailsElements.map(
+        (index, details) =>
+          // eslint-disable-next-line no-new
+          new DetailsContentSynopsis(details),
+      );
+    },
+  };
+
+  /**
+   * The element containing the synopsis of the detail element's contents.
+   *
+   * @return {string}
+   *   The markup for the element that will contain the synopsis text.
+   */
+  Drupal.theme.synopsizedDetailsContentWrapper = () =>
+    `<span class="summary"></span>`;
+
+  /**
+   * Formats a summary's synopsis text.
+   *
+   * @param {string|null} [text]
+   *   (optional) The synopsis text displayed by the summary.
+   * @return {string}
+   *   The formatted synopsis text.
+   */
+  Drupal.theme.synopsizedDetailsContent = text => (text ? ` (${text})` : '');
+})(jQuery, Drupal);
diff --git a/core/misc/details.js b/core/misc/details-content-synopsis.js
similarity index 52%
rename from core/misc/details.js
rename to core/misc/details-content-synopsis.js
index a080141a4c..f3b60768c3 100644
--- a/core/misc/details.js
+++ b/core/misc/details-content-synopsis.js
@@ -6,43 +6,38 @@
 **/
 
 (function ($, Drupal) {
-  function DetailsEnhanced(node) {
+  function DetailsContentSynopsis(node) {
     this.$node = $(node);
     this.setupSummary();
   }
 
-  $.extend(DetailsEnhanced, {
+  $.extend(DetailsContentSynopsis, {
     instances: []
   });
-  $.extend(DetailsEnhanced.prototype, {
+  $.extend(DetailsContentSynopsis.prototype, {
     setupSummary: function setupSummary() {
-      this.$summarySupplementalContent = $(Drupal.theme('summarySupplementalContent'));
-      this.$node.on('summaryUpdated', $.proxy(this.onSummaryUpdated, this)).trigger('summaryUpdated').find('> summary').append(this.$summarySupplementalContent);
+      this.$synopsizedDetailsContentWrapper = $(Drupal.theme('synopsizedDetailsContentWrapper'));
+      this.$node.on('summaryUpdated', $.proxy(this.onSummaryUpdated, this)).trigger('summaryUpdated').find('> summary').append(this.$synopsizedDetailsContentWrapper);
     },
     onSummaryUpdated: function onSummaryUpdated() {
       var text = $.trim(this.$node.drupalGetSummary());
-      this.$summarySupplementalContent.html(Drupal.theme('summarySupplementalContentText', text));
+      this.$synopsizedDetailsContentWrapper.html(Drupal.theme('synopsizedDetailsContent', text));
     }
   });
   Drupal.behaviors.detailsSummary = {
     attach: function attach(context) {
       var $detailsElements = $(context).find('details').once('details');
-
-      if ($detailsElements.length) {
-        for (var i = 0; i < $detailsElements.length; i++) {
-          Drupal.EnhancedDetailsElements.instances.push(new DetailsEnhanced($detailsElements[i]));
-        }
-      }
+      $detailsElements.map(function (index, details) {
+        return new DetailsContentSynopsis(details);
+      });
     }
   };
 
-  Drupal.theme.summarySupplementalContent = function () {
+  Drupal.theme.synopsizedDetailsContentWrapper = function () {
     return "<span class=\"summary\"></span>";
   };
 
-  Drupal.theme.summarySupplementalContentText = function (text) {
+  Drupal.theme.synopsizedDetailsContent = function (text) {
     return text ? " (".concat(text, ")") : '';
   };
-
-  Drupal.EnhancedDetailsElements = DetailsEnhanced;
 })(jQuery, Drupal);
\ No newline at end of file
diff --git a/core/misc/details.es6.js b/core/misc/details.es6.js
deleted file mode 100644
index 3dafad664c..0000000000
--- a/core/misc/details.es6.js
+++ /dev/null
@@ -1,109 +0,0 @@
-/**
- * @file
- * Additional functionality for details elements.
- */
-(($, Drupal) => {
-  /**
-   * The DetailsEnhanced object represents a single details element.
-   *
-   * @constructor Drupal.DetailsEnhanced
-   *
-   * @param {HTMLElement} node
-   *   The details element with enhanced functionality.
-   */
-  function DetailsEnhanced(node) {
-    this.$node = $(node);
-    this.setupSummary();
-  }
-
-  $.extend(
-    DetailsEnhanced,
-    /** @lends Drupal.DetailsEnhanced */ {
-      /**
-       * Holds references to instantiated DetailsEnhanced objects.
-       *
-       * @type {Array.<Drupal.DetailsEnhanced>}
-       */
-      instances: [],
-    },
-  );
-
-  $.extend(
-    DetailsEnhanced.prototype,
-    /** @lends Drupal.DetailsEnhanced# */ {
-      /**
-       * Initialize and setup summary events and markup.
-       *
-       * @fires event:summaryUpdated
-       *
-       * @listens event:summaryUpdated
-       */
-      setupSummary() {
-        this.$summarySupplementalContent = $(
-          Drupal.theme('summarySupplementalContent'),
-        );
-        this.$node
-          .on('summaryUpdated', $.proxy(this.onSummaryUpdated, this))
-          .trigger('summaryUpdated')
-          .find('> summary')
-          .append(this.$summarySupplementalContent);
-      },
-
-      /**
-       * Update summary.
-       */
-      onSummaryUpdated() {
-        const text = $.trim(this.$node.drupalGetSummary());
-        this.$summarySupplementalContent.html(
-          Drupal.theme('summarySupplementalContentText', text),
-        );
-      },
-    },
-  );
-
-  /**
-   * Extends functionality of a details element.
-   *
-   * @type {Drupal~behavior}
-   *
-   * @prop {Drupal~behaviorAttach} attach
-   *   Attaches behavior for the details element.
-   */
-  Drupal.behaviors.detailsSummary = {
-    attach(context) {
-      const $detailsElements = $(context)
-        .find('details')
-        .once('details');
-      if ($detailsElements.length) {
-        for (let i = 0; i < $detailsElements.length; i++) {
-          Drupal.EnhancedDetailsElements.instances.push(
-            new DetailsEnhanced($detailsElements[i]),
-          );
-        }
-      }
-    },
-  };
-
-  /**
-   * The element containing a summary's supplemental text.
-   *
-   * @return {string}
-   *   The markup for the element that will contain supplemental summary text.
-   */
-  Drupal.theme.summarySupplementalContent = () =>
-    `<span class="summary"></span>`;
-
-  /**
-   * Formats a summary's supplemental text.
-   *
-   * @param {string|null} [text]
-   *   (optional) The additional text displayed by the summary.
-   * @return {string}
-   *   The formatted text that will be appended to the summary element.
-   */
-  Drupal.theme.summarySupplementalContentText = text =>
-    text ? ` (${text})` : '';
-
-  // Expose constructor in the public space.
-  Drupal.EnhancedDetailsElements = DetailsEnhanced;
-})(jQuery, Drupal);