Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE Documents_with_expenses (document_id VARCHAR, budget_type_code VARCHAR)
### Question:
What are the document ids for the budget type code 'SF'?
### Answer:
SELECT document_id FROM Documents_with_expenses WHERE budget_type_code = 'SF'