In its annual report, Berkshire said the increase, to $18.2 billion, was made in the fourth quarter, and was based on higher-than-expected loss payments reported by AIG. Berkshire also boosted a related deferred charge asset by $1.7 billion, and estimated its year-end net liability under the contract was $10.7 billion. The January 2017 contract called for Berkshire's National Indemnity Co to take on many of the long-term risks in AIG's property and casualty portfolio, sometimes known as "long-tail" exposure, in exchange for $10.2 billion upfront.