diff --git a/lib/OfxParser/Ofx.php b/lib/OfxParser/Ofx.php
index b93c075..72fcb47 100644
--- a/lib/OfxParser/Ofx.php
+++ b/lib/OfxParser/Ofx.php
@@ -324,22 +324,10 @@ private function createDateTimeFromStr($dateString, $ignoreErrors = false)
      */
     private function createAmountFromStr($amountString)
     {
-        // Decimal mark style (UK/US): 000.00 or 0,000.00
-        if (preg_match('/^(-|\+)?([\d,]+)(\.?)([\d]{2})$/', $amountString) === 1) {
-            return (float)preg_replace(
-                ['/([,]+)/', '/\.?([\d]{2})$/'],
-                ['', '.$1'],
-                $amountString
-            );
-        }
+        $amountString = trim($amountString);
 
-        // European style: 000,00 or 0.000,00
-        if (preg_match('/^(-|\+)?([\d\.]+,?[\d]{2})$/', $amountString) === 1) {
-            return (float)preg_replace(
-                ['/([\.]+)/', '/,?([\d]{2})$/'],
-                ['', '.$1'],
-                $amountString
-            );
+        if (preg_match('/^(?<signal>[-\+]?)(?<integer>.*)(?<separator>[\.,])(?<decimals>[\d]+)$/', $amountString, $matches) === 1) {
+            $amountString = $matches['signal'] . preg_replace('/[^\d]+/', '', $matches['integer']) . '.' . $matches['decimals'];
         }
 
         return (float)$amountString;
diff --git a/lib/OfxParser/Parser.php b/lib/OfxParser/Parser.php
index 081c82a..d38f58e 100644
--- a/lib/OfxParser/Parser.php
+++ b/lib/OfxParser/Parser.php
@@ -38,7 +38,9 @@ public function loadFromFile($ofxFile)
      */
     public function loadFromString($ofxContent)
     {
-        $ofxContent = utf8_encode($ofxContent);
+        if (mb_detect_encoding($ofxContent, 'UTF-8', true) !== 'UTF-8') {
+            $ofxContent = utf8_encode($ofxContent);
+        }
         $ofxContent = $this->conditionallyAddNewlines($ofxContent);
 
         $sgmlStart = stripos($ofxContent, '<OFX>');
@@ -77,6 +79,8 @@ private function xmlLoadString($xmlString)
     {
         libxml_clear_errors();
         libxml_use_internal_errors(true);
+        // Replace unescaped ampersands. @see https://www.php.net/manual/en/simplexml.examples-errors.php#115708
+        $xmlString = preg_replace('/&(?!;{6})/', '&amp;', $xmlString);
         $xml = simplexml_load_string($xmlString);
 
         if ($errors = libxml_get_errors()) {