You have 2 problems:
- You are matching very generic
.*\..*
pattern in first rule which will make 2nd rule defunct. - You are not using
RewriteCond %{REQUEST_FILENAME} !-f
to avoid rewriting for real files/directories.
Have your rules like this:
Options +FollowSymLinks -MultiViews
RewriteEngine On
RewriteCond %{REQUEST_FILENAME} -f [OR]
RewriteCond %{REQUEST_FILENAME} -d
RewriteRule ^ - [L]
RewriteRule ^whois/([^/]+)/?$ /whoisrequest/whois.php?whois=$1 [L,QSA]
RewriteRule ^([^/]+)/?$ /details.php?domain=$1 [L,QSA]