Which document provides high-level cost information that is useful when planning for project cost management?

Project charter, because it includes a summary budget but not in details 

Project Charter provides the high level cost information. However, the below inputs are required for deriving the cost management plan.

Project Management Plan, Project Charter, Enterprise Enviornment Factors & Organization Process assets

The derived cost management plan may get revision at various stages of the project, control of the same is a must required skill of an Project management

C is Comprehensive and contain every attach u need to claim or Report or Analyse 

Project Charter provides High level cost information.

the project charter is a document in project in which contains a board frame detailed description for the project including project budget  project duration, assumption and constrain as it includes business case.

project charter document , It contains the total estimating cost for project in high level.

Project Charter will be the input for planning Cost Management since it contains the high level budget allotted for the project.