[["in millions", "as of december 2012", "as of december 2011"], ["net derivative liabilities under bilateral agreements", "$ 27885", "$ 35066"], ["collateral posted", "24296", "29002"], ["additional collateral or termination payments for a one-notch downgrade", "1534", "1303"], ["additional collateral or termination payments for a two-notch downgrade", "2500", "2183"]]