Earnings Per Share - Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Net income attributable to Chart Industries, Inc.
Income from continuing operations	$ 37.5	$ 15.6	$ 13.8	$ 2.0	$ 16.5	$ 13.7	$ 6.3	$ (5.1)	$ 68.9	$ 31.4	$ 32.5
Income from discontinued operations									239.2	15.0	55.5
Net income attributable to Chart Industries, Inc.	$ 257.8	$ 21.7	$ 20.2	$ 8.4	$ 12.4	$ 18.7	$ 14.4	$ 0.9	$ 308.1	$ 46.4	$ 88.0
Earnings per common share – basic:
Income from continuing operations (usd per share)	$ 1.06	$ 0.44	$ 0.39	$ 0.06	$ 0.46	$ 0.38	$ 0.19	$ (0.16)	$ 1.95	$ 0.93	$ 1.05
Income from discontinued operations (usd per share)	6.23	0.18	0.18	0.17	(0.11)	0.14	0.25	0.19	6.76	0.44	1.78
Net income attributable to Chart Industries, Inc. (usd per share)	7.29	0.62	0.57	0.23	0.35	0.52	0.44	0.03	8.71	1.37	2.83
Earnings per common share – diluted:
Income from continuing operations (usd per share)	0.97	0.43	0.39	0.06	0.46	0.37	0.18	(0.15)	1.89	0.89	1.01
Income from discontinued operations (usd per share)	5.72	0.17	0.18	0.17	(0.12)	0.14	0.23	0.18	6.56	0.43	1.72
Net income attributable to Chart Industries, Inc. (usd per share)	$ 6.69	$ 0.60	$ 0.57	$ 0.23	$ 0.34	$ 0.51	$ 0.41	$ 0.03	$ 8.45	$ 1.32	$ 2.73
Weighted average number of common shares outstanding — basic (shares)									35,380	33,910	31,050
Incremental shares issuable upon assumed conversion and exercise of share-based awards (shares)									260	420	770
Incremental shares issuable due to dilutive effect of the Convertible Notes (shares)									530	820	380
Incremental shares issuable due to dilutive effect of warrants (shares)									280	20	0
Weighted average number of common shares outstanding — diluted (shares)									36,450	35,170	32,200