Condensed Consolidating Financial Information - Condensed Consolidating Balance Sheets (Detail) (USD $) In Millions, unless otherwise specified	Feb. 28, 2014	Nov. 30, 2013	Feb. 28, 2013	Nov. 30, 2012
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	$ 144.1	$ 197.6	$ 140.7	$ 162.1
Accounts receivable	199.2	214.1
Inventories	139.2	105.9
Recoverable from the U.S. government, Northrop, and other third parties for environmental remediation costs	28.4	26.4
Other receivables, prepaid expenses and other	22.5	22.4
Income taxes	5.8	12.6
Deferred income taxes	18.6	17.0
Total Current Assets	557.8	596.0
Property, plant and equipment, net	372.7	374.7
Recoverable from the U.S. government and other third parties for environmental remediation costs	86.5	88.7
Deferred income taxes	175.9	175.7
Goodwill	159.4	159.6
Intercompany receivable
Investments in subsidiaries
Other noncurrent assets and intangibles, net	362.3	360.6
Total Assets	1,714.6	1,755.3
Short-term borrowings and current portion of long-term debt	3.0	2.9
Accounts payable	98.0	122.5
Reserves for environmental remediation costs	38.0	36.6
Income taxes
Other current liabilities, advance payments on contracts, and postretirement medical and life insurance benefits	314.5	317.7
Total Current Liabilities	453.5	479.7
Long-term debt	691.1	696.3
Reserves for environmental remediation costs	132.4	134.7
Pension benefits	257.2	261.7
Intercompany payable
Other noncurrent liabilities	132.6	133.1
Total Liabilities	1,666.8	1,705.5
Commitments and contingencies (Note 8)
Redeemable common stock	0.1	0.2
Total shareholders' equity	47.7	49.6
Total Liabilities, Redeemable Common Stock and Shareholders' Equity	1,714.6	1,755.3
Parent [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	143.8	192.7	146.1	172.4
Accounts receivable
Inventories
Recoverable from the U.S. government, Northrop, and other third parties for environmental remediation costs	0.1	0.4
Other receivables, prepaid expenses and other	3.4	2.6
Income taxes	17.0	30.1
Deferred income taxes	11.2	10.9
Total Current Assets	175.5	236.7
Property, plant and equipment, net	4.7	4.7
Recoverable from the U.S. government and other third parties for environmental remediation costs	0.7	0.4
Deferred income taxes	48.3	48.8
Goodwill
Intercompany receivable	152.8	71.5
Investments in subsidiaries	551.2	534.5
Other noncurrent assets and intangibles, net	26.6	27.7
Total Assets	959.8	924.3
Short-term borrowings and current portion of long-term debt	2.7	2.7
Accounts payable	2.2	2.2
Reserves for environmental remediation costs	2.1	3.8
Income taxes
Other current liabilities, advance payments on contracts, and postretirement medical and life insurance benefits	131.0	85.2
Total Current Liabilities	138.0	93.9
Long-term debt	690.6	695.7
Reserves for environmental remediation costs	4.5	4.3
Pension benefits	22.4	23.6
Intercompany payable
Other noncurrent liabilities	56.5	57.0
Total Liabilities	912.0	874.5
Commitments and contingencies (Note 8)
Redeemable common stock	0.1	0.2
Total shareholders' equity	47.7	49.6
Total Liabilities, Redeemable Common Stock and Shareholders' Equity	959.8	924.3
Guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents		4.9
Accounts receivable	195.9	211.4
Inventories	133.8	100.5
Recoverable from the U.S. government, Northrop, and other third parties for environmental remediation costs	28.3	26.0
Other receivables, prepaid expenses and other	18.1	18.8
Income taxes
Deferred income taxes	6.3	4.9
Total Current Assets	382.4	366.5
Property, plant and equipment, net	362.2	364.4
Recoverable from the U.S. government and other third parties for environmental remediation costs	85.8	88.3
Deferred income taxes	108.2	107.2
Goodwill	159.4	159.6
Intercompany receivable
Investments in subsidiaries
Other noncurrent assets and intangibles, net	290.6	289.0
Total Assets	1,388.6	1,375.0
Short-term borrowings and current portion of long-term debt	0.3	0.2
Accounts payable	94.9	119.1
Reserves for environmental remediation costs	35.9	32.8
Income taxes	11.2	16.9
Other current liabilities, advance payments on contracts, and postretirement medical and life insurance benefits	180.7	229.7
Total Current Liabilities	323.0	398.7
Long-term debt	0.5	0.6
Reserves for environmental remediation costs	127.9	130.4
Pension benefits	234.8	238.1
Intercompany payable	184.0	103.7
Other noncurrent liabilities	64.3	64.6
Total Liabilities	934.5	936.1
Commitments and contingencies (Note 8)
Redeemable common stock
Total shareholders' equity	454.1	438.9
Total Liabilities, Redeemable Common Stock and Shareholders' Equity	1,388.6	1,375.0
Non-guarantor Subsidiaries [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	0.3
Accounts receivable	3.3	2.7
Inventories	5.4	5.4
Recoverable from the U.S. government, Northrop, and other third parties for environmental remediation costs
Other receivables, prepaid expenses and other	1.0	1.0
Income taxes
Deferred income taxes	1.1	1.2
Total Current Assets	11.1	10.3
Property, plant and equipment, net	5.8	5.6
Recoverable from the U.S. government and other third parties for environmental remediation costs
Deferred income taxes	19.4	19.7
Goodwill
Intercompany receivable	31.2	32.2
Investments in subsidiaries
Other noncurrent assets and intangibles, net	45.1	43.9
Total Assets	112.6	111.7
Short-term borrowings and current portion of long-term debt
Accounts payable	0.9	1.2
Reserves for environmental remediation costs
Income taxes		0.6
Other current liabilities, advance payments on contracts, and postretirement medical and life insurance benefits	2.8	2.8
Total Current Liabilities	3.7	4.6
Long-term debt
Reserves for environmental remediation costs
Pension benefits
Intercompany payable
Other noncurrent liabilities	11.8	11.5
Total Liabilities	15.5	16.1
Commitments and contingencies (Note 8)
Redeemable common stock
Total shareholders' equity	97.1	95.6
Total Liabilities, Redeemable Common Stock and Shareholders' Equity	112.6	111.7
Eliminations [Member]
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents			(5.4)	(10.3)
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	(11.2)	(17.5)
Deferred income taxes
Total Current Assets	(11.2)	(17.5)
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	(184.0)	(103.7)
Investments in subsidiaries	(551.2)	(534.5)
Other noncurrent assets and intangibles, net
Total Assets	(746.4)	(655.7)
Short-term borrowings and current portion of long-term debt
Accounts payable
Reserves for environmental remediation costs
Income taxes	(11.2)	(17.5)
Other current liabilities, advance payments on contracts, and postretirement medical and life insurance benefits
Total Current Liabilities	(11.2)	(17.5)
Long-term debt
Reserves for environmental remediation costs
Pension benefits
Intercompany payable	(184.0)	(103.7)
Other noncurrent liabilities
Total Liabilities	(195.2)	(121.2)
Commitments and contingencies (Note 8)
Redeemable common stock
Total shareholders' equity	(551.2)	(534.5)
Total Liabilities, Redeemable Common Stock and Shareholders' Equity	$ (746.4)	$ (655.7)