v3.26.3
Shareholder Report, Average Annual Return (Details)
 12 Months Ended 60 Months Ended 96 Months Ended 106 Months Ended 120 Months Ended
Aug. 31, 2026
Aug. 31, 2026
Aug. 31, 2026
Aug. 31, 2026
Aug. 31, 2026
C000080842 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Institutional Shares        
Average Annual Return, Percent 2.49% 1.92%     1.78%
C000080841 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Admiral Shares        
Average Annual Return, Percent 2.42% 1.89%     1.76%
C000080843 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name ETF Shares Net Asset Value        
Average Annual Return, Percent 2.47% 1.92%     1.78%
C000080846 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name ETF Shares Net Asset Value        
Average Annual Return, Percent 0.71% (0.16%)     1.15%
C000080844 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Admiral Shares        
Average Annual Return, Percent 0.66% (0.19%)     1.12%
C000080845 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Institutional Shares        
Average Annual Return, Percent 0.66% (0.18%)     1.14%
C000080848 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Institutional Shares        
Average Annual Return, Percent 0.17% (6.87%)     (1.79%)
C000080847 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Admiral Shares        
Average Annual Return, Percent 0.17% (6.90%)     (1.81%)
C000080849 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name ETF Shares Net Asset Value        
Average Annual Return, Percent 0.19% (6.87%)     (1.79%)
C000080852 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name ETF Shares Net Asset Value        
Average Annual Return, Percent 2.78% 2.38%     2.67%
C000080850 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Admiral Shares        
Average Annual Return, Percent 2.76% 2.35%     2.65%
C000080851 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Institutional Shares        
Average Annual Return, Percent 2.76% 2.37%     2.67%
C000080854 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Institutional Shares        
Average Annual Return, Percent 1.65% 0.69%     2.62%
C000080853 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Admiral Shares        
Average Annual Return, Percent 1.63% 0.68%     2.61%
C000080855 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name ETF Shares Net Asset Value        
Average Annual Return, Percent 1.90% 0.75%     2.65%
C000080858 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name ETF Shares Net Asset Value        
Average Annual Return, Percent 0.82% (3.28%)     1.47%
C000080856 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Admiral Shares        
Average Annual Return, Percent (0.22%) (3.49%)     1.35%
C000080857 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Institutional Shares        
Average Annual Return, Percent (0.21%) (3.48%)     1.36%
C000080860 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Institutional Shares        
Average Annual Return, Percent 3.11% 0.35%     1.25%
C000080859 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Admiral Shares        
Average Annual Return, Percent 3.09% 0.34%     1.23%
C000080861 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name ETF Shares Net Asset Value        
Average Annual Return, Percent 3.12% 0.36%     1.25%
C000195056 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name ETF Shares Net Asset Value        
Average Annual Return, Percent 1.94% (0.15%)   2.23%  
C000203194 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name ETF Shares Net Asset Value        
Average Annual Return, Percent 1.33% (0.16%) 1.73%    
Without Sales Load [Member] | C000080843 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name ETF Shares Market Price        
Average Annual Return, Percent 2.43% 1.92%     1.78%
Without Sales Load [Member] | C000080846 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name ETF Shares Market Price        
Average Annual Return, Percent 0.65% (0.17%)     1.14%
Without Sales Load [Member] | C000080849 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name ETF Shares Market Price        
Average Annual Return, Percent 0.09% (6.88%)     (1.80%)
Without Sales Load [Member] | C000080852 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name ETF Shares Market Price        
Average Annual Return, Percent 2.76% 2.37%     2.64%
Without Sales Load [Member] | C000080855 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name ETF Shares Market Price        
Average Annual Return, Percent 1.95% 0.74%     2.62%
Without Sales Load [Member] | C000080858 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name ETF Shares Market Price        
Average Annual Return, Percent 0.92% (3.27%)     1.46%
Without Sales Load [Member] | C000080861 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name ETF Shares Market Price        
Average Annual Return, Percent 3.16% 0.37%     1.26%
Without Sales Load [Member] | C000195056 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name ETF Shares Market Price        
Average Annual Return, Percent 1.89% (0.17%)   2.22%  
Without Sales Load [Member] | C000203194 [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name ETF Shares Market Price        
Average Annual Return, Percent 1.35% (0.16%) 1.73%    
Bloomberg U S Aggregate Float Adjusted Index [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Bloomberg U.S. Aggregate Float Adjusted Index        
Average Annual Return, Percent 1.84% (0.29%)   1.57% 1.42%
Bloomberg Global Aggregate Float Adjusted Index [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Bloomberg Global Aggregate Float Adjusted Index        
Average Annual Return, Percent 1.08% (1.32%) 1.01%    
Spliced Bloomberg U S Treasury 1 3 Year Index [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Spliced Bloomberg U.S. Treasury 1–3 Year Index        
Average Annual Return, Percent 2.49% 1.95%     1.82%
Spliced Bloomberg U S Treasury 3 10 Year Index [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Spliced Bloomberg U.S.Treasury 3–10 Year Index        
Average Annual Return, Percent 0.72% (0.14%)     1.18%
Spliced Bloomberg U S Long Treasury Index [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Spliced Bloomberg U.S. Long Treasury Index        
Average Annual Return, Percent 0.18% (6.85%)     (1.75%)
Bloomberg U S 1 5 Year Corporate Bond Index [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Bloomberg U.S. 1–5 Year Corporate Bond Index        
Average Annual Return, Percent 2.80% 2.40%     2.74%
Bloomberg U S 5 10 Year Corporate Bond Index [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Bloomberg U.S. 5–10 Year Corporate Bond Index        
Average Annual Return, Percent 1.93% 0.80%     2.74%
Bloomberg U S 10 Year Corporate Bond Index [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Bloomberg U.S. 10+ Year Corporate Bond Index        
Average Annual Return, Percent 0.89% (3.26%)     1.51%
Bloomberg U S MBS Float Adjusted Index [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Bloomberg U.S. MBS Float Adjusted Index        
Average Annual Return, Percent 3.12% 0.42%     1.34%
Bloomberg U S Corporate Bond Index [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Bloomberg U.S. Corporate Bond Index        
Average Annual Return, Percent 1.94% (0.12%)   2.31%  
Bloomberg Global Aggregate Float Adjusted Composite Index [Member]          
Average Annual Return [Line Items]          
Line Graph and Table Measure Name Bloomberg Global Aggregate Float Adjusted Composite Index        
Average Annual Return, Percent 1.44% (0.12%) 1.80%