Confused about linq this query

I have an xml file like this.

<Accounts>
    <Account Id="">
        <UserName/>
        <Password/>
        <AddingDate/>
        <AccountType/>
    </Account>
</Accounts>

What I want to do is that if the first element's attaribute value is not empty return true otherwise false

private bool IsListEmpty(){    
    XDocument doc = XDocument.Load("UserAccounts.xml");

    var c = from p in doc.Descendants("Account") 
            where p.Element("Id").Value == "" 
            select p.Value;

    if(c==null)return......
}

But I am stuck.How can I do this