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 - Restricted Shares (Details)

Stock-Based Compensation Expense - Restricted Shares (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of restricted stock as deferred compensation to employees and directors		18,578
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period, Value		$ 385
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Exercised (in shares)			(46,623)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Exercised, weighted average exercise price (in dollars per share)			$ 20.67
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, beginning of period (in shares)	0	0	17,516
Granted (in shares)	0	0	0
Exercised (in shares)	0	0	(17,516)
Forfeited (in shares)	0	0	0
Outstanding, end of period (in shares)	0	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Options outstanding, weighted average grant price, beginning of period (in dollars per share)	$ 0.00	$ 0.00	$ 20.09
Granted, weighted average exercise price (in dollars per share)	0.00	0.00	0.00
Exercised, weighted average exercise price (in dollars per share)	0.00	0.00	20.09
Forfeited, weighted average exercise price (in dollars per share)	0.00	0.00	0.00
Options outstanding, weighted average grant price, end of period (in dollars per share)	$ 0.00	$ 0.00	$ 0.00
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Aggregate intrinsic value	$ 4,338
Total unrecognized expense related to non-vested stock option awards	$ 2,817
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Outstanding, beginning of period (in shares)	192,221	198,822	164,325
Granted (in shares)	135,855	98,009	96,462
Exercised (in shares)	(111,611)	(69,704)
Forfeited (in shares)	(8,319)	(34,906)	(15,342)
Outstanding, end of period (in shares)	208,146	192,221	198,822
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Options outstanding, weighted average grant price, beginning of period (in dollars per share)	$ 23.36	$ 22.38	$ 20.53
Granted, weighted average exercise price (in dollars per share)	18.65	24.08	24.44
Exercised, weighted average exercise price (in dollars per share)	22.74	21.97
Forfeited, weighted average exercise price (in dollars per share)	21.25	22.53	20.76
Options outstanding, weighted average grant price, end of period (in dollars per share)	$ 20.64	$ 23.36	$ 22.38
Stock based compensation, recognition period	1 year 9 months 4 days
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period, Value	$ 881	$ 1,113	$ 1,187
Total unrecognized expense related to non-vested stock option awards	$ 761
Vested shares	0	31,658,000	19,446,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Granted (in shares)	0	22,989,000	15,162,000
Forfeited (in shares)	0	(8,669,000)	(4,284,000)
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Roll Forward]
Stock based compensation, recognition period	1 year 6 months 18 days
Minimum [Member] \| Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Compensation Arrangement, Possible Number Of Shares Issued Each Year	0	0	0
Maximum [Member] \| Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Based Compensation Arrangement, Possible Number Of Shares Issued Each Year	94,972,000	76,172,000	77,406,000
Common Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of restricted stock as deferred compensation to employees and directors	19,824
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Exercised (in shares)	(43,121)	(29,056)	(88,050)