Java REGEX With Document Filter

I have been trying to figure out a REGEX expressions which can filter characters which are not '-' or 0-9. This expression will be used with a document filter which will filter characters being inserted into JTextFields. Let me explain in more detail...

When a user enters a character into a JTextField a DocumentFilter checks the input using the 'insertString' method in the DocumentFilter class. Because the method is called every time a character is inserted the REGEX needed to be able to handle parts of an integer as the user builds the string. For example,

Key Press 1): Value = '-' PASS
Key Press 2): Value = '-1' PASS
Key Press 3): Value = '-10' PASS etc...

However the filter should not allow the combination '-0' or '--' and should pass the following cases,

Negative Symbol Only ('-')

Negative Number Without Zero Next To '-' ('-01' fail)

Positive Values (0122 and 122 pass)

Here is my code:

package regex;

import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.DocumentFilter;

public class CustomFilter extends DocumentFilter {

    private String regex = "((-?)([1-9]??))(\d)";

    /**
     * Called every time a new character is added.
     */
    @Override
    public void insertString(DocumentFilter.FilterBypass fb, int offset, String string, AttributeSet attr) throws BadLocationException {

        String text = fb.getDocument().getText(0, fb.getDocument().getLength());
        text += string;

        if(text.matches(regex)) {
            super.insertString(fb, offset, string, attr);
        }
    }

    /**
     * Called when the user pastes in new text.
     */
    @Override
    public void replace(DocumentFilter.FilterBypass fb, int offset, int length, String text, AttributeSet attrs) throws BadLocationException {

        String string = fb.getDocument().getText(0, fb.getDocument().getLength());
        string += text;

        if(string.matches(regex)) {
            super.replace(fb, offset, length, text, attrs);
        }
    }

    @Override
    public void remove(FilterBypass fb, int offset, int length) throws BadLocationException {
        super.remove(fb, offset, length); // I may modify this later
    }
}

If you believe I am going about this in the wrong direction please let me know. I am open to a more simplistic option.