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

Employee Benefits - (Details) - USD ($) $ in Thousands	12 Months Ended
Employee Benefits - (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Annual vesting percentage	100.00%
Employer matching contribution, percent	50.00%
Maximum annual contribution per employee, percent	6.00%
Employer discretionary contribution, amount	$ 1,634	$ 1,684	$ 1,456
Incentive compensation paid	2,324	2,133	7,491
Thermon Europe B.V. [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Postretirement healthcare obligation, net	1,611	1,590
Postretirement Health Care Costs
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Postemployment benefits expense	$ 289	$ 295	$ 313