v3.25.2
Shareholder Report, Average Annual Return (Details)
 6 Months Ended 9 Months Ended 12 Months Ended 52 Months Ended 60 Months Ended 102 Months Ended 108 Months Ended 120 Months Ended
Jun. 30, 2025
Jun. 30, 2025
Jun. 30, 2025
Jun. 30, 2025
Jun. 30, 2025
Jun. 30, 2025
Jun. 30, 2025
Jun. 30, 2025
Jun. 30, 2025
Jun. 30, 2025
Jun. 30, 2025
Jun. 30, 2025
Diamond Hill Small Cap Fund | Investor Class                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       DH Small Cap Fund - Investor
Average Annual Return, Percent (1.35%)     7.83%     15.61%         6.46%
Diamond Hill Small Cap Fund | Class I                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       DH Small Cap Fund - Class I
Average Annual Return, Percent (1.17%)     8.16%     15.94%         6.77%
Diamond Hill Small Cap Fund | Class Y                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       DH Small Cap Fund - Class Y
Average Annual Return, Percent (1.13%)     8.30%     16.09%         6.90%
Diamond Hill Small-Mid Cap Fund | Investor Class                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       DH Small-Mid Cap Fund - Investor
Average Annual Return, Percent 0.94%     8.20%     12.26%         6.48%
Diamond Hill Small-Mid Cap Fund | Class I                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       DH Small-Mid Cap Fund - Class I
Average Annual Return, Percent 1.09%     8.53%     12.58%         6.79%
Diamond Hill Small-Mid Cap Fund | Class Y                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       DH Small-Mid Cap Fund - Class Y
Average Annual Return, Percent 1.17%     8.65%     12.72%         6.92%
Diamond Hill Mid Cap Fund | Investor Class                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       DH Mid Cap Fund - Investor
Average Annual Return, Percent 4.86%     10.99%     13.15%         6.99%
Diamond Hill Mid Cap Fund | Class I                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       DH Mid Cap Fund - Class I
Average Annual Return, Percent 4.99%     11.32%     13.49%         7.31%
Diamond Hill Mid Cap Fund | Class Y                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       DH Mid Cap Fund - Class Y
Average Annual Return, Percent 5.15%     11.48%     13.63%         7.44%
Diamond Hill Large Cap Fund | Investor Class                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       DH Large Cap Fund - Investor
Average Annual Return, Percent 4.10%     9.67%     12.46%         9.40%
Diamond Hill Large Cap Fund | Class I                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       DH Large Cap Fund - Class I
Average Annual Return, Percent 4.27%     9.99%     12.79%         9.72%
Diamond Hill Large Cap Fund | Class Y                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       DH Large Cap Fund - Class Y
Average Annual Return, Percent 4.33%     10.13%     12.93%         9.84%
Diamond Hill Large Cap Concentrated Fund | Investor Class                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name           DH Large Cap Concentrated Fund - Investor            
Average Annual Return, Percent 7.75%     13.66% 9.87%              
Diamond Hill Large Cap Concentrated Fund | Class I                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name           DH Large Cap Concentrated Fund - Class I            
Average Annual Return, Percent 7.94%     14.10% 10.21%              
Diamond Hill Large Cap Concentrated Fund | Class Y                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name           DH Large Cap Concentrated Fund - Class Y            
Average Annual Return, Percent 8.01%     14.19% 10.32%              
Diamond Hill Select Fund | Investor Class                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       DH Select Fund - Investor
Average Annual Return, Percent 3.54%     9.46%     18.40%         10.19%
Diamond Hill Select Fund | Class I                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       DH Select Fund - Class I
Average Annual Return, Percent 3.65%     9.73%     18.75%         10.51%
Diamond Hill Select Fund | Class Y                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       DH Select Fund - Class Y
Average Annual Return, Percent 3.76%     9.93%     18.90%         10.64%
Diamond Hill Long-Short Fund | Investor Class                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       DH Long-Short Fund - Investor
Average Annual Return, Percent 8.66%     8.55%     10.75%         6.46%
Diamond Hill Long-Short Fund | Class I                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       DH Long-Short Fund - Class I
Average Annual Return, Percent 8.84%     8.89%     11.08%         6.78%
Diamond Hill Long-Short Fund | Class Y                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       DH Long-Short Fund - Class Y
Average Annual Return, Percent 8.89%     9.02%     11.21%         6.90%
Diamond Hill International Fund | Investor Class                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name               DH International Fund - Investor        
Average Annual Return, Percent 15.83%     13.04%     11.71%   9.04%      
Diamond Hill International Fund | Class I                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name               DH International Fund - Class I        
Average Annual Return, Percent 16.03%     13.45%     12.05%   9.36%      
Diamond Hill International Fund | Class Y                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name               DH International Fund - Class Y        
Average Annual Return, Percent 16.12%     13.60%     12.17%   9.48%      
Diamond Hill Short Duration Securitized Bond Fund | Investor Class                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                     DH Short Duration Securitized Bond Fund - Investor  
Average Annual Return, Percent 3.59%     8.33%     5.08%     3.88%    
Diamond Hill Short Duration Securitized Bond Fund | Class I                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                     DH Short Duration Securitized Bond Fund - Class I  
Average Annual Return, Percent 3.83%     8.61%     5.41%     4.19%    
Diamond Hill Short Duration Securitized Bond Fund | Class Y                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                     DH Short Duration Securitized Bond Fund - Class Y  
Average Annual Return, Percent 3.79%     8.74%     5.52%     4.31%    
Diamond Hill Core Bond Fund | Investor Class                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                     DH Core Bond Fund - Investor  
Average Annual Return, Percent 4.05%     6.58%     0.08%     1.85%    
Diamond Hill Core Bond Fund | Class I                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                     DH Core Bond Fund - Class I  
Average Annual Return, Percent 4.16%     6.88%     0.35%     2.13%    
Diamond Hill Core Bond Fund | Class Y                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                     DH Core Bond Fund - Class Y  
Average Annual Return, Percent 4.32%     6.99%     0.47%     2.25%    
Diamond Hill Core Plus Bond Fund | Investor Class                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name   DH Core Plus Bond Fund - Investor                    
Average Annual Return, Percent 4.23%   3.50%                  
Diamond Hill Core Plus Bond Fund | Class I                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name   DH Core Plus Bond Fund - Class I                    
Average Annual Return, Percent 4.31%   3.66%                  
Diamond Hill Core Plus Bond Fund | Class Y                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name   DH Core Plus Bond Fund - Class Y                    
Average Annual Return, Percent 4.47%   3.83%                  
Diamond Hill Small Cap Fund | Investor Class | Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 3000 Index
Average Annual Return, Percent 5.75%     15.30%     15.96%         12.96%
Diamond Hill Small Cap Fund | Class I | Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 3000 Index
Average Annual Return, Percent 5.75%     15.30%     15.96%         12.96%
Diamond Hill Small Cap Fund | Class Y | Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 3000 Index
Average Annual Return, Percent 5.75%     15.30%     15.96%         12.96%
Diamond Hill Small-Mid Cap Fund | Investor Class | Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 3000 Index
Average Annual Return, Percent 5.75%     15.30%     15.96%         12.96%
Diamond Hill Small-Mid Cap Fund | Class I | Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 3000 Index
Average Annual Return, Percent 5.75%     15.30%     15.96%         12.96%
Diamond Hill Small-Mid Cap Fund | Class Y | Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 3000 Index
Average Annual Return, Percent 5.75%     15.30%     15.96%         12.96%
Diamond Hill Mid Cap Fund | Investor Class | Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 3000 Index
Average Annual Return, Percent 5.75%     15.30%     15.96%         12.96%
Diamond Hill Mid Cap Fund | Class I | Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 3000 Index
Average Annual Return, Percent 5.75%     15.30%     15.96%         12.96%
Diamond Hill Mid Cap Fund | Class Y | Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 3000 Index
Average Annual Return, Percent 5.75%     15.30%     15.96%         12.96%
Diamond Hill Large Cap Fund | Investor Class | Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 3000 Index
Average Annual Return, Percent 5.75%     15.30%     15.96%         12.96%
Diamond Hill Large Cap Fund | Class I | Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 3000 Index
Average Annual Return, Percent 5.75%     15.30%     15.96%         12.96%
Diamond Hill Large Cap Fund | Class Y | Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 3000 Index
Average Annual Return, Percent 5.75%     15.30%     15.96%         12.96%
Diamond Hill Large Cap Concentrated Fund | Investor Class | Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name           Russell 3000 Index            
Average Annual Return, Percent 5.75%     15.30% 11.95%              
Diamond Hill Large Cap Concentrated Fund | Class I | Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name           Russell 3000 Index            
Average Annual Return, Percent 5.75%     15.30% 11.95%              
Diamond Hill Large Cap Concentrated Fund | Class Y | Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name           Russell 3000 Index            
Average Annual Return, Percent 5.75%     15.30% 11.95%              
Diamond Hill Select Fund | Investor Class | Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 3000 Index
Average Annual Return, Percent 5.75%     15.30%     15.96%         12.96%
Diamond Hill Select Fund | Class I Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 3000 Index
Average Annual Return, Percent 5.75%     15.30%     15.96%         12.96%
Diamond Hill Select Fund | Class Y | Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 3000 Index
Average Annual Return, Percent 5.75%     15.30%     15.96%         12.96%
Diamond Hill Long-Short Fund | Investor Class | Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 3000 Index
Average Annual Return, Percent 5.75%     15.30%     15.96%         12.96%
Diamond Hill Long-Short Fund | Class I | Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 3000 Index
Average Annual Return, Percent 5.75%     15.30%     15.96%         12.96%
Diamond Hill Long-Short Fund | Class Y | Russell 3000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 3000 Index
Average Annual Return, Percent 5.75%     15.30%     15.96%         12.96%
Diamond Hill International Fund | Investor Class | MSCI ACWI ex USA Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name               MSCI ACWI ex USA Index        
Average Annual Return, Percent 17.90%     17.72%     10.13%   7.92%      
Diamond Hill International Fund | Class I | MSCI ACWI ex USA Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name               MSCI ACWI ex USA Index        
Average Annual Return, Percent 17.90%     17.72%     10.13%   7.92%      
Diamond Hill International Fund | Class Y | MSCI ACWI ex USA Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name               MSCI ACWI ex USA Index        
Average Annual Return, Percent 17.90%     17.72%     10.13%   7.92%      
Diamond Hill Short Duration Securitized Bond Fund | Investor Class | Bloomberg US Aggregate Bond Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                     Bloomberg US Aggregate Bond Index  
Average Annual Return, Percent 4.02%     6.08%     (0.73%)     1.22%    
Diamond Hill Short Duration Securitized Bond Fund | Class I | Bloomberg US Aggregate Bond Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                     Bloomberg US Aggregate Bond Index  
Average Annual Return, Percent 4.02%     6.08%     (0.73%)     1.22%    
Diamond Hill Short Duration Securitized Bond Fund | Class Y | Bloomberg US Aggregate Bond Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                     Bloomberg US Aggregate Bond Index  
Average Annual Return, Percent 4.02%     6.08%     (0.73%)     1.22%    
Diamond Hill Core Bond Fund | Investor Class | Bloomberg US Aggregate Bond Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                     Bloomberg US Aggregate Bond Index  
Average Annual Return, Percent 4.02%     6.08%     (0.73%)     1.22%    
Diamond Hill Core Bond Fund | Class I | Bloomberg US Aggregate Bond Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                     Bloomberg US Aggregate Bond Index  
Average Annual Return, Percent 4.02%     6.08%     (0.73%)     1.22%    
Diamond Hill Core Bond Fund | Class Y | Bloomberg US Aggregate Bond Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                     Bloomberg US Aggregate Bond Index  
Average Annual Return, Percent 4.02%     6.08%     (0.73%)     1.22%    
Diamond Hill Core Plus Bond Fund | Investor Class | Bloomberg US Aggregate Bond Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name   Bloomberg US Aggregate Bond Index                    
Average Annual Return, Percent 4.02%   2.00%                  
Diamond Hill Core Plus Bond Fund | Class I | Bloomberg US Aggregate Bond Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name   Bloomberg US Aggregate Bond Index                    
Average Annual Return, Percent 4.02%   2.00%                  
Diamond Hill Core Plus Bond Fund | Class Y | Bloomberg US Aggregate Bond Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name   Bloomberg US Aggregate Bond Index                    
Average Annual Return, Percent 4.02%   2.00%                  
Diamond Hill Small Cap Fund | Investor Class | Russell 2000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 2000 Index
Average Annual Return, Percent (1.79%)     7.68%     10.04%         7.12%
Diamond Hill Small Cap Fund | Class I | Russell 2000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 2000 Index
Average Annual Return, Percent (1.79%)     7.68%     10.04%         7.12%
Diamond Hill Small Cap Fund | Class Y | Russell 2000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 2000 Index
Average Annual Return, Percent (1.79%)     7.68%     10.04%         7.12%
Diamond Hill Small-Mid Cap Fund | Investor Class | Russell 2500 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 2500 Index
Average Annual Return, Percent 0.44%     9.91%     11.44%         8.39%
Diamond Hill Small-Mid Cap Fund | Class I | Russell 2500 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 2500 Index
Average Annual Return, Percent 0.44%     9.91%     11.44%         8.39%
Diamond Hill Small-Mid Cap Fund | Class Y | Russell 2500 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 2500 Index
Average Annual Return, Percent 0.44%     9.91%     11.44%         8.39%
Diamond Hill Mid Cap Fund | Investor Class | Russell Midcap Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell Midcap Index
Average Annual Return, Percent 4.84%     15.21%     13.11%         9.89%
Diamond Hill Mid Cap Fund | Class I | Russell Midcap Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell Midcap Index
Average Annual Return, Percent 4.84%     15.21%     13.11%         9.89%
Diamond Hill Mid Cap Fund | Class Y | Russell Midcap Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell Midcap Index
Average Annual Return, Percent 4.84%     15.21%     13.11%         9.89%
Diamond Hill Large Cap Fund | Investor Class | Russell 1000 Value Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 1000 Value Index
Average Annual Return, Percent 6.00%     13.70%     13.93%         9.19%
Diamond Hill Large Cap Fund | Investor Class | Russell 1000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 1000 Index
Average Annual Return, Percent 6.12%     15.66%     16.30%         13.35%
Diamond Hill Large Cap Fund | Class I | Russell 1000 Value Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 1000 Value Index
Average Annual Return, Percent 6.00%     13.70%     13.93%         9.19%
Diamond Hill Large Cap Fund | Class I | Russell 1000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 1000 Index
Average Annual Return, Percent 6.12%     15.66%     16.30%         13.35%
Diamond Hill Large Cap Fund | Class Y | Russell 1000 Value Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 1000 Value Index
Average Annual Return, Percent 6.00%     13.70%     13.93%         9.19%
Diamond Hill Large Cap Fund | Class Y | Russell 1000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 1000 Index
Average Annual Return, Percent 6.12%     15.66%     16.30%         13.35%
Diamond Hill Large Cap Concentrated Fund | Investor Class | Russell 1000 Value Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name           Russell 1000 Value Index            
Average Annual Return, Percent 6.00%     13.70% 9.61%              
Diamond Hill Large Cap Concentrated Fund | Investor Class | Russell 1000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name           Russell 1000 Index            
Average Annual Return, Percent 6.12%     15.66% 12.65%              
Diamond Hill Large Cap Concentrated Fund | Class I | Russell 1000 Value Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name           Russell 1000 Value Index            
Average Annual Return, Percent 6.00%     13.70% 9.61%              
Diamond Hill Large Cap Concentrated Fund | Class I | Russell 1000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name           Russell 1000 Index            
Average Annual Return, Percent 6.12%     15.66% 12.65%              
Diamond Hill Large Cap Concentrated Fund | Class Y | Russell 1000 Value Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name           Russell 1000 Value Index            
Average Annual Return, Percent 6.00%     13.70% 9.61%              
Diamond Hill Large Cap Concentrated Fund | Class Y | Russell 1000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name           Russell 1000 Index            
Average Annual Return, Percent 6.12%     15.66% 12.65%              
Diamond Hill Long-Short Fund | Investor Class | Russell 1000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 1000 Index
Average Annual Return, Percent 6.12%     15.66%     16.30%         13.35%
Diamond Hill Long-Short Fund | Investor Class | 60% Russell 1000/40% Bloomberg US T-Bill 1-3 Month Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       60% Russell 1000/40% Bloomberg US T-Bill 1-3 Month Index
Average Annual Return, Percent 4.64%     11.38%     11.08%         8.99%
Diamond Hill Long-Short Fund | Class I | Russell 1000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 1000 Index
Average Annual Return, Percent 6.12%     15.66%     16.30%         13.35%
Diamond Hill Long-Short Fund | Class I | 60% Russell 1000/40% Bloomberg US T-Bill 1-3 Month Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       60% Russell 1000/40% Bloomberg US T-Bill 1-3 Month Index
Average Annual Return, Percent 4.64%     11.38%     11.08%         8.99%
Diamond Hill Long-Short Fund | Class Y | Russell 1000 Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       Russell 1000 Index
Average Annual Return, Percent 6.12%     15.66%     16.30%         13.35%
Diamond Hill Long-Short Fund | Class Y | 60% Russell 1000/40% Bloomberg US T-Bill 1-3 Month Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                       60% Russell 1000/40% Bloomberg US T-Bill 1-3 Month Index
Average Annual Return, Percent 4.64%     11.38%     11.08%         8.99%
Diamond Hill Short Duration Securitized Bond Fund | Investor Class | Bloomberg US 1-3 Year Government/Credit Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                     Bloomberg US 1-3 Year Government/Credit Index  
Average Annual Return, Percent 2.92%     5.94%     1.58%     1.87%    
Diamond Hill Short Duration Securitized Bond Fund | Class I | Bloomberg US 1-3 Year Government/Credit Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                     Bloomberg US 1-3 Year Government/Credit Index  
Average Annual Return, Percent 2.92%     5.94%     1.58%     1.87%    
Diamond Hill Short Duration Securitized Bond Fund | Class Y | Bloomberg US 1-3 Year Government/Credit Index                        
Average Annual Return [Line Items]                        
Line Graph and Table Measure Name                     Bloomberg US 1-3 Year Government/Credit Index  
Average Annual Return, Percent 2.92%     5.94%     1.58%     1.87%