Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Net revenue
Operating expenses:
Selling, general and administrative	1,400	2,100
Total operating expenses	1,400	(2,100)
Operating (loss) from operations	(1,400)	(2,100)
Other income (expense):
Interest expense	(900)	(500)
Realized loss on investments		(2,200)
Defined benefit plan adjustment		(8,500)
Other income, net		100
Total other expense	(900)	(11,100)
Loss from operations before income taxes	(2,300)	(13,200)
Loss from operations	(2,300)	(13,200)
Net loss	(2,300)	(13,200)
Less: Net loss attributable to noncontrolling interest	(100)	(400)
Net loss attributable to GlassBridge Enterprises, Inc.	$ (2,200)	$ (12,800)
Loss per common share attributable to GlassBridge Enterprises, Inc. common shareholders - basic and diluted:
Net loss	$ (87.30)	$ (507.69)
Weighted average common shares outstanding:
Basic and diluted	25,200	25,200