CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Revenues	$ 1,346.4	$ 1,249.7	$ 1,145.6
Cost of sales	1,287.3	1,183.0	1,070.7
Gross profit	59.1	66.7	74.9
Selling, general and administrative expenses	52.3	61.0	56.0
Losses on derivative financial instruments, net	2.1	0.2	4.2
Amortization of identifiable intangible assets	2.4	2.4	2.0
Goodwill impairment	33.6	61.8	0.0
Identifiable intangible asset impairment	10.1	0.1	0.0
Property, plant and equipment impairment	40.5
Other operating expense, net	2.6	5.9	2.5
Operating profit (loss)	(84.5)	(64.7)	10.2
Nonoperating expense (income):
Interest expense, net	41.7	37.3	34.9
Change in fair value of common stock warrant liability	(4.4)	(2.4)	1.5
Acquisition-related costs and expenses		1.0	14.8
Loss (earnings) from equity method investment	(2.9)	1.1
Foreign exchange losses (gains) on intercompany loans	(2.4)	2.4	1.3
Reorganization items, net	11.7
Other, net	0.4	(0.3)	(1.5)
Total nonoperating expense, net	44.1	39.1	51.0
Loss from continuing operations before income taxes	(128.6)	(103.8)	(40.8)
Income tax benefit	(7.8)	(0.6)	(9.1)
Loss from continuing operations	(120.8)	(103.2)	(31.7)
Earnings (loss) from discontinued operations, net of income taxes		0.6	24.9
Net loss	(120.8)	(102.6)	(6.8)
Earnings from continuing operations attributable to noncontrolling interest	0.9	0.3	0.1
Net loss attributable to Real Industry, Inc.	(121.7)	(102.9)	(6.9)
LOSS PER SHARE:
Net loss attributable to Real Industry, Inc.	(121.7)	(102.9)	(6.9)
Dividends on Redeemable Preferred Stock, in-kind		(2.0)	(1.5)
Dividends on Redeemable Preferred Stock, in cash or accrued	(2.4)
Accretion of fair value adjustment to Redeemable Preferred Stock	(3.6)	(1.0)	(0.8)
Net loss available to common stockholders	$ (127.7)	$ (105.9)	$ (9.2)
Basic and diluted loss per share:
Continuing operations	$ (4.41)	$ (3.68)	$ (0.35)
Basic and diluted loss per share	$ (4.41)	$ (3.68)	$ (0.35)