Restatement - Summary of the Impact to Pretax Income (Loss) from Continuing Operations by Reporting Period (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		9 Months Ended	12 Months Ended
	Dec. 31, 2015	Mar. 31, 2016	Feb. 28, 2015	Aug. 31, 2015	Nov. 30, 2014	Nov. 30, 2013
Error Corrections and Prior Period Adjustments Restatement [Line Items]
(Loss) income from continuing operations before income taxes	$ 9.0	$ 8.7	$ (9.3)
Contract Accounting [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
(Loss) income from continuing operations before income taxes				$ 0.0	$ 1.9	$ (2.0)
Other Individually Immaterial Items [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
(Loss) income from continuing operations before income taxes				(1.2)	(1.5)	0.3
Rocketdyne Business [Member] | Purchase Accounting [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
(Loss) income from continuing operations before income taxes				(0.5)	3.1	(7.8)
Rocketdyne Business [Member] | Contract Accounting [Member]
Error Corrections and Prior Period Adjustments Restatement [Line Items]
(Loss) income from continuing operations before income taxes				$ 1.3	$ 2.9	$ 0.0