Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Statement [Abstract]
Net loss	$ (2,300)	$ (13,200)
Net pension adjustments, net of tax:
Reclassification of adjustment for defined benefit plans recorded in net loss		20,600
Total net pension adjustments		20,600
Total other comprehensive income, net of tax		20,600
Comprehensive income (loss)	(2,300)	7,400
Less: Comprehensive loss attributable to noncontrolling interest	(100)
Comprehensive income (loss) attributable to GlassBridge Enterprises, Inc.	$ (2,200)	$ 7,400