Equity Method Investment - Summarized Financial Information (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Jun. 30, 2020	Dec. 31, 2019	Jun. 30, 2019	Dec. 31, 2018
Schedule of Equity Method Investments [Line Items]
Receivable due from equity method investment	$ 94		$ 94			$ 96
Current assets	140,228		140,228			98,510
Total assets	371,568		371,568			355,756
Current liabilities	121,313		121,313			114,625
Total liabilities and members’ equity	31,202	$ 70,925	31,202	$ 70,925	$ 35,462	53,273	$ 73,569	$ 93,390
Net income	(3,523)	(2,303)	(20,822)	(21,922)
Charah Solutions’ share of net income	625	667	1,247	1,884
Equity method investments
Schedule of Equity Method Investments [Line Items]
Current assets	2,657		2,657			2,482
Noncurrent assets	310		310			395
Total assets	2,967		2,967			2,877
Current liabilities	377		377			321
Total liabilities and members’ equity	2,967		2,967			2,877
Revenue	2,353	2,647	5,377	7,400
Net income	1,252	$ 1,334	2,495	$ 3,767
Equity of Charah | Equity method investments
Schedule of Equity Method Investments [Line Items]
Total liabilities and members’ equity	5,095		5,095			5,078
Equity of joint venture partner | Equity method investments
Schedule of Equity Method Investments [Line Items]
Total liabilities and members’ equity	$ (2,505)		$ (2,505)			$ (2,522)