Average Market Price of Common Stock and the Incremental Shares that were Dilutive or Potentially Dilutive (Detail) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Average market price of Real Industry common stock	$ 7.02	$ 9.22	$ 9.58
Potentially dilutive common stock equivalents:
Total potentially dilutive common stock equivalents	3,147,787	2,763,306	2,682,205
Unvested Restricted Common Stock
Potentially dilutive common stock equivalents:
Total potentially dilutive common stock equivalents	597,246	259,323	114,505
Outstanding Common Stock Options
Potentially dilutive common stock equivalents:
Total potentially dilutive common stock equivalents	748,150	775,650	1,067,700
Unvested Restricted Stock Units
Potentially dilutive common stock equivalents:
Total potentially dilutive common stock equivalents	354,058	260,000	0
Warrants
Potentially dilutive common stock equivalents:
Total potentially dilutive common stock equivalents	1,448,333	1,468,333	1,500,000