XML 391 R20.htm IDEA: XBRL DOCUMENT v3.20.4
Annual Total Returns- Vanguard Extended Duration Treasury Index Fund (ETF) [BarChart] - ETF - Vanguard Extended Duration Treasury Index Fund - ETF Shares
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
Total 10.27% 55.81% 3.18% (20.94%) 45.64% (4.45%) 1.52% 13.52% (3.51%) 19.14%