Unusual Items - Narrative (Details) - USD ($) $ in Millions	3 Months Ended							6 Months Ended		9 Months Ended		12 Months Ended
	Aug. 31, 2015	May. 31, 2015	Feb. 28, 2015	Nov. 30, 2014	Aug. 31, 2014	May. 31, 2014	Feb. 28, 2014	May. 31, 2015	May. 31, 2014	Aug. 31, 2015	Aug. 31, 2014	Nov. 30, 2015	Nov. 30, 2014	Nov. 30, 2013
Unusual or Infrequent Item [Line Items]
Loss on legal settlement	$ 50.0									$ 50.0		$ 50.0	$ 0.0	$ 0.0
Loss associated with write-off of deferred financing fees	$ 1.1	$ 0.5	$ 0.2	$ 0.0	$ 9.8	$ 45.9	$ 4.9	$ 0.7	$ 50.8	$ 1.8	$ 60.6	1.9	60.6	5.0
Loss on bank amendment			$ 0.0				$ 0.0		$ 0.2		$ 0.2	0.0	0.2	0.0
Realized losses (gains) and interest												(0.1)	0.9	(1.0)
Charge related to legal settlement														0.5
Rocketdyne Business [Member]
Unusual or Infrequent Item [Line Items]
Expenses incurred related to Rocketdyne Business acquisition														20.0
Internal labor costs														$ 1.4
Senior Credit Facility [Member]
Unusual or Infrequent Item [Line Items]
Loss on bank amendment													$ 0.2
Delayed Draw Term Loan [Member]
Unusual or Infrequent Item [Line Items]
Principal amount of loan retired												76.0
Loss associated with write-off of deferred financing fees												$ 1.9