[["in millions", "december 31 2012 amortized cost", "december 31 2012 fair value", "december 31 2012 amortized cost", "fair value"], ["total securities available for sale ( a )", "$ 49447", "$ 51052", "$ 48609", "$ 48568"], ["total securities held to maturity", "10354", "10860", "12066", "12450"], ["total securities", "$ 59801", "$ 61912", "$ 60675", "$ 61018"]]