The FRED series Nonprofit Organizations - Assets - Balance Sheet of Households and Nonprofit Organizations is now known as Nonprofit Organizations; Real Estate at Market Value.
The source series id is FL165035005.Q.
This series appears in Table B.101. 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), Nonprofit Organizations; Real Estate at Market Value, Level (DISCONTINUED) [NOABSHNO], retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series/NOABSHNO, April 19, 2018.