(Loss) Earnings Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Numerator:
Net income (loss) attributable to Charah Solutions, Inc.	$ (18,026)	$ 3,220	$ (20,845)	$ 4,025
Denominator (in thousands):
Weighted-average shares outstanding used in (loss) earnings per common share, basic (in shares)	29,558,752	24,477,829	29,374,295	24,096,186
Dilutive share-based awards (in shares)	0	870,000	0	846,000
Total weighted average shares outstanding, including dilutive shares (in shares)	29,558,752	25,347,887	29,374,295	24,942,199
Basic (loss) earnings per common share (in dollars per share)	$ (0.61)	$ 0.13	$ (0.71)	$ 0.17
Diluted (loss) earnings per common share (in dollars per share)	$ (0.61)	$ 0.13	$ (0.71)	$ 0.16
Antidilutive securities excluded from computation of earnings per share (in shares)	1,388,000		1,191,000