The status of an open order stays 'submitted' until the complete order is filled. Here is the part from the documetation:
'Filled - indicates that the order has been completely filled.'
I think that is clear. Please see here the complete documentation for the order-status:
status
The order status. Possible values include:
PendingSubmit - indicates that you have transmitted the order, but have not yet received confirmation that it has been accepted by the order destination. NOTE: This order status is not sent by TWS and should be explicitly set by the API developer when an order is submitted.
PendingCancel - indicates that you have sent a request to cancel the order but have not yet received cancel confirmation from the order destination. At this point, your order is not confirmed canceled. You may still receive an execution while your cancellation request is pending. NOTE: This order status is not sent by TWS and should be explicitly set by the API developer when an order is canceled.
PreSubmitted - indicates that a simulated order type has been accepted by the IB system and that this order has yet to be elected. The order is held in the IB system until the election criteria are met. At that time the order is transmitted to the order destination as specified.
Submitted - indicates that your order has been accepted at the order destination and is working.
Cancelled - indicates that the balance of your order has been confirmed canceled by the IB system. This could occur unexpectedly when IB or the destination has rejected your order.
Filled - indicates that the order has been completely filled.
Inactive - indicates that the order has been accepted by the system (simulated orders) or an exchange (native orders) but that currently the order is inactive due to system, exchange or other issues.
Daniel