Consolidated Statements of Operations - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Income Statement [Abstract]
Net revenue	$ 36.5	$ 44.1
Cost of goods sold	19.8	24.7
Gross profit	16.7	19.4
Operating expenses:
Selling, general and administrative	29.0	34.9
Research and development	8.1	11.9
GBAM Fund expenses	0.5	0.0
Impaired Charges:
Goodwill	3.8	0.0
Intangible assets	2.7	0.0
Restructuring and other	1.9	7.6
Total operating expenses	46.0	54.4
Operating loss from continuing operations	(29.3)	(35.0)
Other income (expense):
Interest income	0.0	0.2
Net gains from GBAM Fund activities	1.2	0.0
Other income (expense), net	(0.6)	(4.9)
Total other income (expense)	0.6	(4.7)
Loss from continuing operations before income taxes	(28.7)	(39.7)
Income tax benefit (provision)	5.8	(0.1)
Loss from continuing operations	(22.9)	(39.8)
Discontinued operations:
Income (loss) from discontinued operations, net of income taxes	4.3	(13.4)
Gain on sale of discontinued businesses, net of income taxes	0.0	3.8
Reclassification of cumulative translation adjustment	0.0	(75.8)
Income (loss) from discontinued operations, net of income taxes	4.3	(85.4)
Net loss including noncontrolling interest	(18.6)	(125.2)
Less: Net loss attributable to noncontrolling interest	(10.2)	0.0
Net loss attributable to GlassBridge Enterprises, Inc.	$ (8.4)	$ (125.2)
Income (loss) per common share attributable to GlassBridge common shareholders — basic and diluted:
Continuing operations (in dollars per share)	$ (2.70)	$ (10.76)
Discontinued operations (in dollars per share)	0.91	(23.08)
Net loss (in dollars per share)	$ (1.79)	$ (33.84)
Weighted average common shares outstanding:
Basic and diluted (in shares)	4.7	3.7