Commitments and Contingencies - Summary of Northrop Agreement Activity (Details) - Northrop [Member] - USD ($) $ in Millions	May. 31, 2015	Nov. 30, 2014
Contingencies And Commitments [Line Items]
Total reimbursable costs under the Northrop Agreement	$ 189.7
Amount reimbursed to the Company through May 31, 2015	(110.2)
Potential future cost reimbursements available	79.5
Less: Long-term receivable from Northrop included in the unaudited condensed consolidated balance sheet as of May 31, 2015	(69.7)	$ (74.8)
Less: Short-term receivable from Northrop included in the unaudited condensed consolidated balance sheet as of May 31, 2015	(6.0)	$ (6.0)
Less: Amounts recoverable from Northrop included in recoverable from the U.S. government and other third parties for environmental remediation costs in the unaudited condensed consolidated balance sheet as of May 31, 2015	(3.8)
Potential future recoverable amounts available under the Northrop Agreement	$ 0.0