Loss Per Share - Calculation of EPS (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Numerator:
Net loss attributable to Charah Solutions, Inc.	$ (3,536)	$ (18,026)	$ (17,786)	$ (20,845)
Deemed and imputed dividends on Series A Preferred Stock	(167)	0	(167)	0
Series A Preferred Stock dividends	(858)	0	(969)	0
Net loss attributable to common stockholders	$ (4,561)	$ (18,026)	$ (18,922)	$ (20,845)
Denominator:
Weighted-average shares outstanding (in shares)	29,927	29,559	29,785	29,374
Dilutive share-based awards (in shares)	0	0	0	0
Total weighted average shares outstanding, including dilutive shares (in shares)	29,927	29,559	29,785	29,374
Basic loss per share (in dollars per share)	$ (0.15)	$ (0.61)	$ (0.64)	$ (0.71)
Diluted loss per share (in dollars per share)	$ (0.15)	$ (0.61)	$ (0.64)	$ (0.71)