Income (loss) Per Common Share - Computation of Weighted Average Basic and Diluted Income Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Earnings Per Share [Abstract]
Numerator: Loss from continuing operations	$ (1,800)	$ (1,100)	$ (15,000)	$ (200)
Numerator: Less: loss attributable to noncontrolling interest	(300)		(700)
Numerator: Net loss from continuing operations attributable to GlassBridge Enterprises, Inc.	(1,500)		14,300
Numerator: Income from discontinued operations, net of income taxes		500		11,000
Net income (loss) attributable to GlassBridge Enterprises, Inc.	$ (1,500)	$ (600)	$ (14,300)	$ 9,000
Denominator: Weighted average number of common shares outstanding during the period - basic and diluted	25,200	25,700	25,200	25,700
Income (loss) per common share attributable to GlassBridge Enterprises, Inc. common shareholders - basic and diluted: Continuing operations	$ (59.37)	$ (42.80)	$ (567.06)	$ (77.82)
Income (loss) per common share attributable to GlassBridge Enterprises, Inc. common shareholders - basic and diluted: Discontinued operations		19.46		428.02
Net income (loss)	$ (59.37)	$ (23.34)	$ (567.06)	$ 350.20
Anti-dilutive shares excluded from calculation	0	0	0	0