Quarterly report pursuant to Section 13 or 15(d)

Basis of Presentation and Accounting Policy Information (Details)

v2.4.0.6
Basis of Presentation and Accounting Policy Information (Details) (USD $)
In Thousands, unless otherwise specified
 3 Months Ended 6 Months Ended 12 Months Ended
Jun. 30, 2012
Sep. 30, 2012
Sep. 30, 2011
Mar. 31, 2012
Apr. 30, 2010
Business acquisition [Line Items]          
Net cash used in operating activities $ (357) $ (13,825) $ 14,782 $ (3,112)  
Net cash used in investing activities (5,706) (3,017) (4,639) (22,671)  
Scenario, Previously Reported
          
Business acquisition [Line Items]          
Net cash used in operating activities (1,600)     (5,293)  
Net cash used in investing activities (6,949)     (24,852)  
Restatement Adjustment
          
Business acquisition [Line Items]          
Net cash used in operating activities 1,243     2,181  
Net cash used in investing activities 1,243     2,181  
Thermon Holding Corp.
          
Business acquisition [Line Items]          
Purchase price to acquire the controlling interest         210,000
Cost of selling controlling interest         129,252
Net cash used in operating activities (357) (13,825) 14,782 (3,112)  
Net cash used in investing activities (5,706) (3,017) (4,639) (22,671)  
Thermon Holding Corp. | Scenario, Previously Reported
          
Business acquisition [Line Items]          
Net cash used in operating activities (1,600)     (5,293)  
Net cash used in investing activities (6,949)     (24,852)  
Thermon Holding Corp. | Restatement Adjustment
          
Business acquisition [Line Items]          
Net cash used in operating activities 1,243     2,181  
Net cash used in investing activities 1,243     2,181  
Thermon Holding Corp. | Group of investors and other private equity firms
          
Business acquisition [Line Items]          
Number of other private equity firms         2
Thermon Holding Corp. | Group of investors and other private equity firms | Thermon Holding Corp. | Predecessor
          
Business acquisition [Line Items]          
Purchase price to acquire the controlling interest         $ 321,500