error while entering passsword using splinter Python

I am trying to enter username and password using splinter in python

from splinter import Browser
br=Browser('chrome')
br.visit('https://onqinsider.hilton.com/Insider/OnQLogin/Login.aspx?APPURL=%2finsider%2flinks%2fPingSSO.aspx%3fresume%3d%252fidp%252fkv72c%252fresumeSAML20%252fidp%252fSSO.ping%26spentity%3durn%253ahilton1507-07%253asaml')
br.fill('txtUserID', 'foo')
br.fill('txtPassword', 'gg')

but i am getting error when entering password and it is not entering password.

selenium.common.exceptions.StaleElementReferenceException: Message: stale element reference: element is not attached to the page document

Please help