UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement Of Income And Comprehensive Income [Abstract]
Net earnings (loss)	$ (10.8)	$ 1.3	$ (22.0)	$ (3.0)
Other comprehensive income (loss):
Currency translation adjustments	0.5	(1.7)	1.8	(2.6)
Amortization of net actuarial gains, net of tax		0.0	(0.1)	0.0
Comprehensive loss	(10.3)	(0.4)	(20.3)	(5.6)
Comprehensive income attributable to noncontrolling interest	0.1	0.1	0.5	0.3
Comprehensive loss attributable to Real Industry, Inc.	$ (10.4)	$ (0.5)	$ (20.8)	$ (5.9)