Failed to stabilize Instance with id

After some quick checks using the CloudFormation validation function and my own spot checks, there were several hyphens ("-") that needed to be removed. Additionally, I'm running on the assumptions that !Ref VPC, !Ref PrivateSubnetIds, and so forth are filled in with your account-specific IDs.

I've included my revised version of your code block below, and I was able to successfully create the stack in my own AWS account.

AWSTemplateFormatVersion: 2010-09-09
Resources:
    DocumentDBSecurityGroup:
        Type: AWS::EC2::SecurityGroup
        Properties:
            GroupName: 'DocumentDB SG'
            GroupDescription: !Sub 'Security Group for the DocumentDb'
            VpcId: !Ref VPC
    DocumentDBSubnetGroup:
        Type: AWS::DocDB::DBSubnetGroup
        Properties:
            DBSubnetGroupDescription: "Subnet group for Document DB cluster"
            DBSubnetGroupName: "document-db-subnet-group"
            SubnetIds: !Ref PrivateSubnetIds
    DocumentDBParameterGroup:
        Type: AWS::DocDB::DBClusterParameterGroup
        Properties:
            Description: "Parameter group for Document DB cluster"
            Family: docdb4.0
            Name: "document-db-paramater-group"
            Parameters:
                audit_logs: "disabled"
    DocumentDBCluster:
        Type: AWS::DocDB::DBCluster
        Properties:
            BackupRetentionPeriod: 7
            DBClusterIdentifier: "docdb"
            DBSubnetGroupName: !Ref DocumentDBSubnetGroup
            DBClusterParameterGroupName: !Ref DocumentDBParameterGroup
            Port: 27017
            PreferredBackupWindow: "07:00-09:30"
            PreferredMaintenanceWindow: "tue:07:00-tue:11:00"
            VpcSecurityGroupIds: !Ref DocumentDBSecurityGroup
            StorageEncrypted: true
    DocumentDBInstance:
        Type: AWS::DocDB::DBInstance
        DependsOn: DocumentDBCluster
        Properties:
            DBClusterIdentifier: !Ref DocumentDBCluster
            DBInstanceClass: db.t3.medium
            DBInstanceIdentifier: "docdb"
            PreferredMaintenanceWindow: "tue:07:00-tue:11:00"