CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (DEFICIT) - USD ($) $ in Millions	Common Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest	Total
Beginning balance at Dec. 31, 2014			$ 482.0	$ (396.3)		$ (0.1)	$ 85.6
Beginning Balance, Shares at Dec. 31, 2014	17,099,882
Net loss attributable to Real Industry, Inc.				(6.9)			(6.9)
Earnings from continuing operations attributable to noncontrolling interest						0.1	0.1
Common stock issued, net			63.3				63.3
Common stock issued, Shares	11,304,673
Common stock acquired		$ (0.1)	0.1	(0.1)			(0.1)
Common stock acquired, Shares	(9,698)	9,698
Issuance of restricted common stock, net of forfeitures, Shares	240,990
Common stock options exercised			1.2				1.2
Common stock options exercised, Shares	229,892
Exercise of Warrants			0.2				0.2
Exercise of Warrants, Shares	26,027
Noncontrolling interest acquired in business combination						0.8	0.8
Share-based compensation expense			1.5				1.5
Dividends and accretion on Redeemable Preferred Stock			(2.3)				(2.3)
Change in accumulated other comprehensive income (loss)					$ (1.0)		(1.0)
Ending balance at Dec. 31, 2015		$ (0.1)	546.0	(403.3)	(1.0)	0.8	142.4
Ending Balance, Shares at Dec. 31, 2015	28,891,766	9,698
Net loss attributable to Real Industry, Inc.				(102.9)			(102.9)
Earnings from continuing operations attributable to noncontrolling interest						0.3	0.3
Issuance of restricted common stock, net of forfeitures		$ 0.2	(0.2)
Issuance of restricted common stock, net of forfeitures, Shares	460,064	(17,862)
Common stock options exercised			0.1				0.1
Common stock options exercised, Shares	27,500	(4,284)
Exercise of Warrants		$ (0.1)	0.2				0.1
Exercise of Warrants, Shares	7,552	12,448
Share-based compensation expense			3.6				3.6
Dividends and accretion on Redeemable Preferred Stock			(3.0)				(3.0)
Change in accumulated other comprehensive income (loss)					(6.1)		(6.1)
Ending balance at Dec. 31, 2016			546.7	(506.2)	(7.1)	1.1	34.5
Ending Balance, Shares at Dec. 31, 2016	29,386,882
Net loss attributable to Real Industry, Inc.				(121.7)			(121.7)
Earnings from continuing operations attributable to noncontrolling interest						0.9	0.9
Common stock acquired, Shares	(5,909)	5,909
Conversion of restricted stock, shares	36,649	(5,909)
Issuance of restricted common stock, net of forfeitures, Shares	303,562
Common stock options exercised, Shares	750
Share-based compensation expense			2.1				2.1
Dividends and accretion on Redeemable Preferred Stock			(6.0)				(6.0)
Distribution to noncontrolling interest						(2.3)	(2.3)
Consolidation of noncontrolling interest			(0.5)			0.5
Change in accumulated other comprehensive income (loss)					11.6		11.6
Ending balance at Dec. 31, 2017			$ 542.3	$ (627.9)	$ 4.5	$ 0.2	$ (80.9)
Ending Balance, Shares at Dec. 31, 2017	29,721,934