The FRED series Total Assets - Balance Sheet of Nonfarm Nonfinancial Corporate Business is now known as Nonfinancial Corporate Business; Total Assets.
The source series id is FL102000005.Q.
This series appears in Table B.103. For further information see the assistance provided in the guide to the Financial Accounts at http://www.federalreserve.gov/apps/fof/.
Board of Governors of the Federal Reserve System (US), Nonfinancial Corporate Business; Total Assets, Level [TABSNNCB], retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series/TABSNNCB, April 26, 2018.