Increase contractual field to accept 10 million

Site is a large hospital and often has receipts in the millions. They have had several days when their contractual total over 10Million. The insurance receipt screen truncates numbers over 9,999,999.99. The review screen was not out of balance, so they didn't catch this until trying to balance cash. If it can't accept the larger total, maybe give a warning that the totals are truncated and they need to split the transactions.