diff --git a/src/Document.js b/src/Document.js
index c8cb540..757594d 100644
--- a/src/Document.js
+++ b/src/Document.js
@@ -10,12 +10,27 @@
 
   static TYPE_HTML_FRAGMENT = 2;
 
+  /**
+   * The internal `libxmljs.Document` instance.
+   */
   _original = null;
 
+  /**
+   * Tells whether the `Document` has content.
+   */
   _hasContent = false;
 
+  /**
+   * The object that holds the namespace information.
+   */
   namespace = null;
 
+  /**
+   * Creates a new `Document`.
+   * @param {string} [source] The source as a string.
+   * @param {number} [type] The type of the `Document`.
+   * @param {libxmljs.ParserOptions} [options] The parser options.
+   */
   constructor(source = null, type = Document.TYPE_XML, options = null) {
     if (source !== null) {
       switch (type) {
@@ -38,18 +53,29 @@
     }
   }
 
+  /**
+   * An array containing the errors in the current `Document`.
+   */
   get errors() {
     if (!this._original) return [];
 
     return this._original.errors;
   }
 
+  /**
+   * An array containing the validation errors in the current `Document`.
+   */
   get validationErrors() {
     if (!this._original) return undefined;
 
     return this._original.validationErrors;
   }
 
+  /**
+   * Gets the idxth child of the root node.
+   * @param {number} idx
+   * @returns {libxmljs.Element|null} A `libxmljs.Element` or `null`.
+   */
   child(idx) {
     this.assertNoContentError();
 
@@ -58,26 +84,48 @@
     return this._original.child(idx);
   }
 
+  /**
+   * Gets all the children of the root node.
+   * @returns {Element[]} An array of `libxmljs.Element`s.
+   */
   childNodes() {
     this.assertNoContentError();
 
     return this._original.childNodes();
   }
 
+  /**
+   * Counts the amount of results of the provided XPath.
+   * @param {string} xpath The XPath to count.
+   * @returns {number} The amount of results.
+   */
   count(xpath) {
     if (typeof xpath !== 'string') throw new Error('xpath must be a string.');
 
     return this.get(`count(${xpath})`);
   }
 
+  /**
+   * Gets the `Document`'s encoding.
+   * @returns {string} The `Document`'s encoding.
+   */
   encoding() {
     return this._original.encoding();
   }
 
+  /**
+   * Sets the `Document`'s encoding.
+   * @returns {string} The `Document`.
+   */
   encoding(enc) {
     return this._original.encoding(enc);
   }
 
+  /**
+   * Finds the result of the provided XPath.
+   * @param {string} xpath The XPath to find.
+   * @returns {libxmljs.Element[]} An array of `libxmljs.Element`s.
+   */
   find(xpath) {
     this.assertNoContentError();
     if (typeof xpath !== 'string') throw new Error('xpath must be a string.');
@@ -89,6 +137,12 @@
     return this._original.find(fullXPath, { [this.namespace.alias]: this.namespace.url });
   }
 
+  /**
+   * Parses an HTML document.
+   * @param {string} html The HTML content.
+   * @param {libxmljs.ParserOptions} [options] The parser options.
+   * @returns {Document} The `Document`.
+   */
   fromHtml(html, options = {}) {
     if (typeof html !== 'string') throw new Error('html must be a string.');
     if (typeof options !== 'object') throw new Error('options must be an object.');
@@ -99,6 +153,12 @@
     return this;
   }
 
+  /**
+   * Parses an HTML fragment.
+   * @param {string} htmlFragment The HTML content.
+   * @param {libxmljs.ParserOptions} [options] The parser options.
+   * @returns {Document} The `Document`.
+   */
   fromHtmlFragment(htmlFragment, options = {}) {
     if (typeof htmlFragment !== 'string') throw new Error('htmlFragment must be a string.');
     if (typeof options !== 'object') throw new Error('options must be an object.');
@@ -109,6 +169,12 @@
     return this;
   }
 
+  /**
+   * Parses an XML document.
+   * @param {string} xml The XML content.
+   * @param {libxmljs.ParserOptions} [options] The parser options.
+   * @returns {Document} The `Document`.
+   */
   fromXml(xml, options = {}) {
     if (typeof xml !== 'string') throw new Error('htmlFragment must be a string.');
     if (typeof options !== 'object') throw new Error('options must be an object.');
@@ -119,6 +185,11 @@
     return this;
   }
 
+  /**
+   * Gets the first result of the provided XPath.
+   * @param {string} xpath The XPath to get.
+   * @returns {libxmljs.Element} A `libxmljs.Element`.
+   */
   get(xpath) {
     const found = this.find(xpath);
 
@@ -128,42 +199,83 @@
     return found[0]; // found is a non-empty array so we return the first element.
   }
 
+  /**
+   * Gets the `Document`'s DTD.
+   * @returns {object} The DTD object.
+   */
   getDtd() {
     return this._original.getDtd();
   }
 
+  /**
+   * Gets the `Document`'s namespaces.
+   * @returns {libxmljs.Namespace[]} An array of `libxmljs.Namespace`s.
+   */
   namespaces() {
     this.assertNoContentError();
 
     return this._original.namespaces();
   }
 
+  /**
+   * Creates the root.
+   * @param {string} name The root's tag name.
+   * @param {string} content The root's text content.
+   * @returns {libxmljs.Node} The created `libxmljs.Node`.
+   */
   node(name, content) {
     if (!this._hasContent) this._hasContent = true;
 
     return this._original.node(name, content);
   }
 
+  /**
+   * Checks whether the `Document` is valid using Relax NG.
+   * @param {object} rng The Relax NG.
+   * @returns {boolean} Whether the `Document` is valid using Relax NG.
+   */
   rngValidate(rng) {
     return this._original.rngValidate(rng);
   }
 
+  /**
+   * Gets the root.
+   * @returns {libxmljs.Element|null} The root or `null`.
+   */
   root() {
     this.assertNoContentError();
 
     return this._original.root();
   }
 
+  /**
+   * Sets the root.
+   * @param {libxmljs.Element} node The root `libxmljs.Element`.
+   * @returns {libxmljs.Element} The created `libxmljs.Element`.
+   */
   root(node) {
     this.assertNoContentError();
 
     return this._original.root(node);
   }
 
+  /**
+   * Sets the `Document`'s DTD.
+   * @param {string} name The name of the DTD.
+   * @param {string} ext The external ID for the DTD.
+   * @param {string} sys The system ID for the DTD.
+   * @returns {void}
+   */
   setDtd(name, ext, sys) {
     return this._original.setDtd(name, ext, sys);
   }
 
+  /**
+   * Sets the `Document`'s namespace.
+   * @param {string} alias The alias of the namespace.
+   * @param {string} url The URL of the namespace.
+   * @returns {Document} The `Document`.
+   */
   setNamespace(alias, url) {
     if (typeof alias !== 'string') throw new Error('alias must be a string.');
     if (typeof url !== 'string') throw new Error('url must be a string.');
@@ -175,14 +287,28 @@
     };
   }
 
+  /**
+   * Returns the `Document` as a string.
+   * @param {boolean} formatting Tells whether the ouput is formatted.
+   * @returns {string} The `Document` as a string.
+   */
   toString(formatting = true) {
     return this._original.toString(formatting);
   }
 
+  /**
+   * Returns the string "document".
+   * @returns {string} "document".
+   */
   type() {
     return this._original.type();
   }
 
+  /**
+   * Validates the `Document` against a XSD document.
+   * @param {Document} xsdDoc The XSD `Document`.
+   * @returns {boolean} Whether the `Document` is valid. `validationErrors` contains the errors if any.
+   */
   validate(xsdDoc) {
     this.assertNoContentError();
     if (!xsdDoc) throw new Error('No XSD document to validate against.');
@@ -190,10 +316,17 @@
     return this._original.validate(xsdDoc);
   }
 
+  /**
+   * Gets the `Document`'s version.
+   * @returns {string} The `Document`'s version.
+   */
   version() {
     return this._original.version();
   }
 
+  /**
+   * Throws an error if the `Document` has no content.
+   */
   assertNoContentError() {
     if (!this._hasContent) {
       const err = new Error('No parsed content found.');