Thermon Group Holdings, Inc. Annual report pursuant to Section 13 and 15(d)

Annual report pursuant to Section 13 and 15(d)

Stock-Based Compensation Expense (Details)

Stock-Based Compensation Expense (Details) (USD $)	12 Months Ended			0 Months Ended
Stock-Based Compensation Expense (Details) (USD $)	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013	May 05, 2011	Jul. 28, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess tax deduction from stock options exercises		$ (118,000)	$ 4,131,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Stock compensation expense	3,295,000	2,203,000	1,341,000
Restricted Stock and Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares of the company's common stock that may be awarded					2,767,171
2011 Long-term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares of the company's common stock that may be awarded					2,893,341
IPO [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation expense associated with the acceleration of the pre-IPO options				6,310,000
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of stock options exercised	1,654,000	10,285,000	18,387,000
Vesting period (in years)	5 years
Annual vesting percentage	20.00%
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Options outstanding, beginning of period (in shares)	558,466.000	1,132,780	2,179,625
Granted (in shares)			56,532
Exercised (in shares)	(88,050)	(566,487)	(1,086,486)
Forfeited (in shares)	(5,374)	(7,827)	(16,891)
Options outstanding, end of period (in shares)	465,042.000	558,466.000	1,132,780
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Options outstanding, weighted average exercise price, beginning of period (in dollars per share)	$ 7.96	$ 6.98	$ 5.74
Granted, weighted average exercise price (in dollars per share)			$ 21.52
Exercised, weighted average exercise price (in dollars per share)	$ 6.87	$ 5.90	$ 5.31
Forfeited, weighted average exercise price (in dollars per share)	$ 12.04	$ 15.73	$ 7.98
Options outstanding, weighted average exercise price, end of period (in dollars per share)	$ 8.12	$ 7.96	$ 6.98
Closing price (in dollars per share)	$ 24.07
Total unrecognized expense related to non-vested stock option awards	430,000
Stock based compensation, recognition period	1 year 7 months 10 days
Stock Options [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Expiration term	10 years
Stock Options [Member] \| IPO [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, vested and exercisable (in shares)				2,757,524
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Total fair value of options issued	289
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Exercised (in shares)	(18,000)	(21,000)	(8,000)
Forfeited (in shares)	0	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Granted, weighted average exercise price (in dollars per share)	$ 0.00	$ 20.09	$ 21.52
Exercised, weighted average exercise price (in dollars per share)	$ 20.09	$ 18.09	$ 12.42
Forfeited, weighted average exercise price (in dollars per share)	$ 0.00	$ 0.00	$ 0.00
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Forfeited (in shares)	(4,284)	(1,660)
Vested shares	19,446	12,254
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Total unrecognized expense related to non-vested stock option awards	650,000
Total fair value of options issued	1,187,000	480,000	960,000
Amortization Period For The Fair Value Share Based Compsensation Award (in years)	3 years
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period	46,530
Performance Shares [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Possible number of shares issued each year	0	0	0
Performance Shares [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Possible number of shares issued each year	93,000	58,076	29,000
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Excess tax deduction from stock options exercises		$ (118,000)	$ 4,131,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Exercised (in shares)	(88,050)	(566,487)	(1,086,486)