Contingencies (Details) (USD $) In Thousands, unless otherwise specified	1 Months Ended	3 Months Ended			9 Months Ended
	Jan. 31, 2012	Jan. 01, 2012 Y	Oct. 02, 2011	Jul. 03, 2011	Jan. 01, 2012 Y	Mar. 31, 2011
Contingencies
Changes related to preexisting warranties	$ 7,805	$ 7,614	$ (1,706)	$ (352)
Increase in litigation reserve under the tentative agreement	25,500
Unbilled receivables for contract claims		117,949			117,949
Environmental liabilities discount rate, net of estimated inflation (as a percent)		0.75%			0.75%	2.50%
Environmental receivable discount rate, net of estimated inflation (as a percent)		0.75%			0.75%	2.50%
Treasury constant maturities rate used to estimate discount rate (in years)		20			20
Estimated inflationary factor (as a percent)		1.90%			1.90%
Environmental remediation
Amounts (payable) receivable		(61,565)			(61,565)	(59,869)
Unamortized discount		2,854			2,854	7,983
Present value amounts (payable) receivable		(58,711)			(58,711)	(51,886)
Amounts (payable) receivable		35,609			35,609	34,337
Unamortized discount		(1,465)			(1,465)	(3,862)
Present value amounts (payable) receivable		34,144			34,144	30,475
Discounted liability		58,711			58,711	51,886
Discounted liability recorded in other current liabilities		5,104			5,104	4,160
Discounted liability recorded in other long-term liabilities		53,607			53,607	47,726
Discounted receivable		34,144			34,144	30,475
Discounted receivable recorded in other current assets		4,679			4,679
Discounted receivable recorded in other non-current assets		29,465			29,465
Discounted range of reasonably possible costs of environmental remediation, low estimate					58,710
Discounted range of reasonably possible costs of environmental remediation, high estimate					$ 91,277