Quarterly report pursuant to Section 13 or 15(d)

Stock-Based Compensation Expense (Details)

v2.4.0.6
Stock-Based Compensation Expense (Details) (USD $)
3 Months Ended 9 Months Ended 0 Months Ended 9 Months Ended 0 Months Ended 9 Months Ended 0 Months Ended 9 Months Ended 0 Months Ended 9 Months Ended 3 Months Ended 9 Months Ended 0 Months Ended 9 Months Ended 0 Months Ended 9 Months Ended 0 Months Ended 9 Months Ended 0 Months Ended 9 Months Ended
Dec. 31, 2012
Dec. 31, 2011
Dec. 31, 2012
Stock_Option_Award_Plans
Dec. 31, 2011
Aug. 02, 2012
Jul. 28, 2010
Restricted Stock and Stock Option Plan
Jul. 28, 2010
2011 Long-term Incentive Plan
Aug. 02, 2012
Stock Options
Dec. 31, 2012
Stock Options
Dec. 31, 2012
Stock Options
Minimum
Dec. 31, 2012
Stock Options
Maximum
Aug. 02, 2012
Restricted Stock Awards
Dec. 31, 2012
Restricted Stock Awards
Aug. 02, 2012
Restricted Stock Units
Dec. 31, 2012
Restricted Stock Units
Aug. 02, 2012
Performance Shares
Dec. 31, 2012
Performance Shares
Executive_Officers
Dec. 31, 2012
Performance Shares
Minimum
Dec. 31, 2012
Performance Shares
Maximum
Dec. 31, 2012
Thermon Holding Corp.
Dec. 31, 2011
Thermon Holding Corp.
Dec. 31, 2012
Thermon Holding Corp.
Dec. 31, 2011
Thermon Holding Corp.
Aug. 02, 2012
Thermon Holding Corp.
Aug. 02, 2012
Thermon Holding Corp.
Stock Options
Dec. 31, 2012
Thermon Holding Corp.
Stock Options
Dec. 31, 2012
Thermon Holding Corp.
Stock Options
Minimum
Dec. 31, 2012
Thermon Holding Corp.
Stock Options
Maximum
Aug. 02, 2012
Thermon Holding Corp.
Restricted Stock Awards
Dec. 31, 2012
Thermon Holding Corp.
Restricted Stock Awards
Aug. 02, 2012
Thermon Holding Corp.
Restricted Stock Units
Dec. 31, 2012
Thermon Holding Corp.
Restricted Stock Units
Aug. 02, 2012
Thermon Holding Corp.
Performance Shares
Dec. 31, 2012
Thermon Holding Corp.
Performance Shares
Executive_Officers
Dec. 31, 2012
Thermon Holding Corp.
Performance Shares
Minimum
Dec. 31, 2012
Thermon Holding Corp.
Performance Shares
Maximum
Stock-Based Compensation Expense                                                                        
Number of stock option award plans     2                                                                  
Maximum number of shares of the company's common stock that may be awarded           2,767,171 2,893,341                                                          
Options outstanding (in shares) 1,337,376   1,337,376                                                                  
Stock compensation expense $ 475,000 $ 58,000 $ 869,000 $ 6,456,000                               $ 475,000 $ 58,000 $ 869,000 $ 6,456,000                          
Stock compensation expense associated with the acceleration of the pre-IPO options       6,310,000                                     6,310,000                          
Stock options granted in period               56,532                                 56,532                      
Stock awards granted in period                       12,546   71,923   44,146                         12,546   71,923   44,146      
Closing price per share         $ 21.52                                     $ 21.52                        
Assumptions used to estimate grant date fair value of employee stock options granted                                                                        
Share Price                 501,000                                 501,000                    
Estimated volatility (as a percent)                 40.50%                                 40.50%                    
Risk free rate (as a percent)                 0.63%                                 0.63%                    
Life of options                 6 years 7 months 28 days                                 6 years 7 months 28 days                    
Expected dividend                 0.00                                 0.00                    
Period in which fair value of options will be expensed on a straight line basis                 5 years       1 year   3 years   3 years                 5 years       1 year   3 years   3 years    
Number of executives issued stock                                 4                                 4    
Total fair value of options issued                         $ 270,000   $ 1,548,000   $ 960,000                         $ 270,000   $ 1,548,000   $ 960,000    
Possible number of shares issued each year                                   0 29,430                               0 29,430
Vesting period                   5 years 10 years                               5 years 10 years                
Expiration term                     10 years                                 10 years