UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Statement Of Income And Comprehensive Income [Abstract]
Net loss	$ (6.2)	$ (1.2)	$ (17.5)	$ (11.2)
Other comprehensive income (loss):
Currency translation adjustments	5.0	(1.4)	5.7	1.3
Amortization of net actuarial gains				(0.1)
Comprehensive loss	(1.2)	(2.6)	(11.8)	(10.0)
Comprehensive income attributable to noncontrolling interest	0.3	0.3	0.4	0.4
Comprehensive loss attributable to Real Industry, Inc.	$ (1.5)	$ (2.9)	$ (12.2)	$ (10.4)