Condensed Consolidating Financial Information - Condensed Consolidating Balance Sheets (Detail) (USD $) In Millions, unless otherwise specified	Nov. 30, 2013	Nov. 30, 2012	Nov. 30, 2011	Nov. 30, 2010
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	$ 197.6	$ 162.1	$ 188.0	$ 181.5
Accounts receivable	214.1	111.5
Inventories	105.9	46.9
Recoverable from the U.S. government, Northrop, and other third parties for environmental remediation costs	26.4	28.3
Other receivables, prepaid expenses and other	22.4	16.8
Income taxes	12.6	2.5
Deferred income taxes	17.0
Total current assets	596.0	368.1
Property, plant and equipment, net	374.7	143.9
Recoverable from the U.S. government and other third parties for environmental remediation costs	88.7	107.9
Deferred income taxes	175.7
Goodwill	159.6	94.9	94.9
Intercompany receivable
Investments in subsidiaries
Other noncurrent assets and intangibles, net	360.6	204.5
Total Assets	1,755.3	919.3
Short-term borrowings and current portion of long-term debt	2.9	2.7
Accounts payable	122.5	56.1
Reserves for environmental remediation costs	36.6	39.5
Income taxes payable
Other current liabilities, advance payments on contracts, and postretirement medical and life insurance benefits	317.7	220.3
Total Current Liabilities	479.7	318.6
Long-term debt	696.3	246.0
Reserves for environmental remediation costs	134.7	150.0
Pension benefits	261.7	454.5
Intercompany payable
Other noncurrent liabilities	133.1	139.0
Total Liabilities	1,705.5	1,308.1
Commitments and contingencies (Note 8)
Redeemable common stock (Note 9)	0.2	3.9
Total shareholders' (deficit) equity	49.6	(392.7)	(211.6)	(200.2)
Total Liabilities, Redeemable Common Stock and Shareholders' Equity (Deficit)	1,755.3	919.3
Parent [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	192.7	172.4	204.7	197.3
Accounts receivable
Inventories
Recoverable from the U.S. government, Northrop, and other third parties for environmental remediation costs	0.4	0.1
Other receivables, prepaid expenses and other	2.6	7.0
Income taxes	30.1	28.8
Deferred income taxes	10.9
Total current assets	236.7	208.3
Property, plant and equipment, net	4.7	4.7
Recoverable from the U.S. government and other third parties for environmental remediation costs	0.4	0.7
Deferred income taxes	48.8
Goodwill
Intercompany receivable	71.5
Investments in subsidiaries	534.5	143.1
Other noncurrent assets and intangibles, net	27.7	17.6
Total Assets	924.3	374.4
Short-term borrowings and current portion of long-term debt	2.7	2.4
Accounts payable	2.2	3.1
Reserves for environmental remediation costs	3.8	3.5
Income taxes payable
Other current liabilities, advance payments on contracts, and postretirement medical and life insurance benefits	85.2	28.1
Total Current Liabilities	93.9	37.1
Long-term debt	695.7	245.3
Reserves for environmental remediation costs	4.3	3.6
Pension benefits	23.6	70.8
Intercompany payable		339.0
Other noncurrent liabilities	57.0	67.4
Total Liabilities	874.5	763.2
Commitments and contingencies (Note 8)
Redeemable common stock (Note 9)	0.2	3.9
Total shareholders' (deficit) equity	49.6	(392.7)
Total Liabilities, Redeemable Common Stock and Shareholders' Equity (Deficit)	924.3	374.4
Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	4.9
Accounts receivable	211.4	109.7
Inventories	100.5	40.5
Recoverable from the U.S. government, Northrop, and other third parties for environmental remediation costs	26.0	28.2
Other receivables, prepaid expenses and other	18.8	9.1
Income taxes
Deferred income taxes	4.9
Total current assets	366.5	187.5
Property, plant and equipment, net	364.4	133.8
Recoverable from the U.S. government and other third parties for environmental remediation costs	88.3	107.2
Deferred income taxes	107.2
Goodwill	159.6	94.9
Intercompany receivable		308.5
Investments in subsidiaries
Other noncurrent assets and intangibles, net	289.0	146.3
Total Assets	1,375.0	978.2
Short-term borrowings and current portion of long-term debt	0.2	0.3
Accounts payable	119.1	61.8
Reserves for environmental remediation costs	32.8	36.0
Income taxes payable	16.9	25.4
Other current liabilities, advance payments on contracts, and postretirement medical and life insurance benefits	229.7	190.6
Total Current Liabilities	398.7	314.1
Long-term debt	0.6	0.7
Reserves for environmental remediation costs	130.4	146.4
Pension benefits	238.1	383.7
Intercompany payable	103.7
Other noncurrent liabilities	64.6	70.4
Total Liabilities	936.1	915.3
Commitments and contingencies (Note 8)
Redeemable common stock (Note 9)
Total shareholders' (deficit) equity	438.9	62.9
Total Liabilities, Redeemable Common Stock and Shareholders' Equity (Deficit)	1,375.0	978.2
Non-guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents
Accounts receivable	2.7	1.8
Inventories	5.4	6.4
Recoverable from the U.S. government, Northrop, and other third parties for environmental remediation costs
Other receivables, prepaid expenses and other	1.0	0.7
Income taxes
Deferred income taxes	1.2
Total current assets	10.3	8.9
Property, plant and equipment, net	5.6	5.4
Recoverable from the U.S. government and other third parties for environmental remediation costs
Deferred income taxes	19.7
Goodwill
Intercompany receivable	32.2	30.5
Investments in subsidiaries
Other noncurrent assets and intangibles, net	43.9	40.6
Total Assets	111.7	85.4
Short-term borrowings and current portion of long-term debt
Accounts payable	1.2	1.5
Reserves for environmental remediation costs
Income taxes payable	0.6	0.9
Other current liabilities, advance payments on contracts, and postretirement medical and life insurance benefits	2.8	1.6
Total Current Liabilities	4.6	4.0
Long-term debt
Reserves for environmental remediation costs
Pension benefits
Intercompany payable
Other noncurrent liabilities	11.5	1.2
Total Liabilities	16.1	5.2
Commitments and contingencies (Note 8)
Redeemable common stock (Note 9)
Total shareholders' (deficit) equity	95.6	80.2
Total Liabilities, Redeemable Common Stock and Shareholders' Equity (Deficit)	111.7	85.4
Eliminations [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		(10.3)	(16.7)	(15.8)
Accounts receivable
Inventories
Recoverable from the U.S. government, Northrop, and other third parties for environmental remediation costs
Other receivables, prepaid expenses and other
Income taxes	(17.5)	(26.3)
Deferred income taxes
Total current assets	(17.5)	(36.6)
Property, plant and equipment, net
Recoverable from the U.S. government and other third parties for environmental remediation costs
Deferred income taxes
Goodwill
Intercompany receivable	(103.7)	(339.0)
Investments in subsidiaries	(534.5)	(143.1)
Other noncurrent assets and intangibles, net
Total Assets	(655.7)	(518.7)
Short-term borrowings and current portion of long-term debt
Accounts payable		(10.3)
Reserves for environmental remediation costs
Income taxes payable	(17.5)	(26.3)
Other current liabilities, advance payments on contracts, and postretirement medical and life insurance benefits
Total Current Liabilities	(17.5)	(36.6)
Long-term debt
Reserves for environmental remediation costs
Pension benefits
Intercompany payable	(103.7)	(339.0)
Other noncurrent liabilities
Total Liabilities	(121.2)	(375.6)
Commitments and contingencies (Note 8)
Redeemable common stock (Note 9)
Total shareholders' (deficit) equity	(534.5)	(143.1)
Total Liabilities, Redeemable Common Stock and Shareholders' Equity (Deficit)	$ (655.7)	$ (518.7)