Segment Reporting (Revenues and Operating Earnings (Losses) by Reportable Segment) (Details) $ in Millions	3 Months Ended		9 Months Ended
	Oct. 31, 2016 USD ($)	Oct. 31, 2015 USD ($)	Oct. 31, 2016 USD ($) segment	Oct. 31, 2015 USD ($)
Reportable Segments [Abstract]
Number of reportable segments | segment			2
Revenues
Revenues	$ 389.0	$ 365.0	$ 1,148.6	$ 1,209.2
Operating earnings (loss)
Operating earnings	38.6	(619.3)	102.7	(539.0)
Interest expense	18.8	19.0	56.8	58.2
Earnings (loss) before income taxes	19.8	(638.3)	45.9	(597.2)
Aerospace Solutions Group
Revenues
Revenues	348.8	306.7	1,039.0	1,006.4
Operating earnings (loss)
Operating earnings	56.5	47.8	174.9	167.7
Energy Services Group
Revenues
Revenues	40.2	58.3	109.6	202.8
Operating earnings (loss)
Operating earnings	$ (17.9)	$ (667.1)	$ (72.2)	$ (706.7)