(Loss) Earnings Per Common Share (Reconciliation of Numerator and Denominator for Calculating Earnings Per Share from Net Income) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Numerator—Basic
Net (loss) income	$ (9,878)	$ 11,865
Less: income attributable to participating shares		399
Less: income attributable to non-controlling interest	2,088	887
Net (loss) income attributable to NCS Multistage Holdings, Inc.—Basic	(11,966)	10,579
Numerator—Diluted
Net (loss) income	(9,878)	11,865
Less: income attributable to non-controlling interest	2,088	887
Net (loss) income attributable to NCS Multistage Holdings, Inc.—Diluted	$ (11,966)	$ 10,978
Denominator
Basic weighted average number of shares (in shares)	45,974,000	44,252,000
Exchangeable shares for common stock (in shares)		1,543,000
Dilutive effect of stock options, RSUs, PSUs and ESPP		1,319,000
Diluted weighted average number of shares (in shares)	45,974,000	47,114,000
(Loss) earnings per common share
Basic (in dollars per share)	$ (0.26)	$ 0.24
Diluted (in dollars per share)	$ (0.26)	$ 0.23
Potentially dilutive securities excluded as anti-dilutive	4,391,000