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

Goodwill and Other Intangible Assets - Intangible Assets related to Acquisition (Details)

Goodwill and Other Intangible Assets - Intangible Assets related to Acquisition (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Net	$ 57,330us-gaap_FiniteLivedIntangibleAssetsNet
Intangible assets, net	100,813	118,917
Unitemp
Finite-Lived Intangible Assets [Line Items]
Weighted average useful life of intangible assets	6 years 8 months 10 days
Gross carrying amount, intangibles	1,255
Accumulated amortization, intangibles	17
Intangible assets, net	1,238
Unitemp \| Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization, finite-lived intangibles	6
Finite-Lived Intangible Assets, Net	362
Estimated lives of intangible assets	5 years
Unitemp \| Trademarks [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization, finite-lived intangibles	8
Finite-Lived Intangible Assets, Net	772
Estimated lives of intangible assets	8 years
Unitemp \| Developed Technology Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization, finite-lived intangibles	3
Finite-Lived Intangible Assets, Net	104
Estimated lives of intangible assets	3 years
CHS Transactions [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount, intangibles	156,685	169,403
Accumulated amortization, intangibles	57,110	50,486
Intangible assets, net	99,575	118,917
CHS Transactions [Member] \| Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization, finite-lived intangibles	44,195	37,383
Finite-Lived Intangible Assets, Net	48,386	62,195
CHS Transactions [Member] \| Developed Technology Rights [Member]
Finite-Lived Intangible Assets [Line Items]
Accumulated amortization, finite-lived intangibles	2,469	2,167
Finite-Lived Intangible Assets, Net	7,393	8,614
Trademarks [Member] \| Unitemp
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets (Excluding Goodwill)	780
Trademarks [Member] \| CHS Transactions [Member]
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets (Excluding Goodwill)	43,034	47,042
Developed Technology Rights [Member] \| Unitemp
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets (Excluding Goodwill)	107
Customer Relationships [Member] \| Unitemp
Finite-Lived Intangible Assets [Line Items]
Indefinite-Lived Intangible Assets (Excluding Goodwill)	$ 368