This excerpt taken from the NUE 10-K filed Feb 27, 2008.
INTEREST EXPENSE (IN COME)
Net interest expense (income) is detailed below:
Gross interest expense increased approximately 27% primarily due to increased average debt outstanding, accompanied by increased average interest rates. During the fourth quarter of 2007, Nucor issued $1.3 billion in notes at rates slightly higher than the majority of the existing debt. Gross interest income decreased approximately 41% primarily due to a decrease in average investments, partially offset by an increase in the average interest rate earned on investments. Average investments decreased 50% due to the cash payments of $1.54 billion for acquisitions and $754.0 million for repurchases of common stock during the year.