Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Statement [Abstract]
Net revenue, primarily related party	$ 500	$ 100
Operating expenses:
Selling, general and administrative	8,900	3,400
Impairment of goodwill	42,300
Restructuring and other		100
Total operating expenses	51,200	3,500
Operating loss from continuing operations	(50,700)	(3,400)
Other income (expense):
Interest expense	(2,600)	(300)
Realized loss on investments	(1,900)
Defined benefit plan adjustment	(8,500)
Unrealized gain on Arrive investment		12,100
Unrealized gain on SportBLX		3,000
Other income (expense), net	100
Total other income (expense)	(12,900)	14,800
Income (loss) from continuing operations before income taxes	(63,600)	11,400
Income tax benefit
Income (loss) from continuing operations	(63,600)	11,400
Discontinued operations:
Income from discontinued operations, net of income taxes		1,300
Gain on sale of discontinued businesses, net of income taxes		10,400
Income from discontinued operations, net of income taxes		11,700
Net Income	(63,600)	23,100
Less: Net loss attributable to noncontrolling interest	(1,300)	2,900
Net Income attributable to GlassBridge Enterprises, Inc.	$ (62,300)	$ 20,200
Earnings (loss) per common share attributable to GlassBridge common shareholders - basic and diluted:
Continuing operations	$ (2,472.77)	$ 330.15
Discontinued operations		461.45
Net Earnings	$ (2,472.77)	$ 791.60
Weighted average common shares outstanding:
Basic and diluted (in thousands)	25,200	25,500