Basis Of Presentation (Narrative) (Details) (USD $)	1 Months Ended	12 Months Ended
	Nov. 30, 2011	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2008
Basis Of Presentation [Line Items]
Date of emergence from bankruptcy proceedings		Nov. 21, 2005
Fresh-start accounting adoption, date		Oct. 01, 2005
Cumulative effect of changes in estimates of long term construction contracts on operating income		$ 48,000,000	$ 59,000,000	$ 41,000,000
Cumulative effect of changes in estimates of long term construction contracts on diluted Earnings Per Share		$ 0.90	$ 1.15	$ 0.62
Cash and cash equivalents, at carrying value		197,114,000	165,801,000	168,205,000	117,548,000
Deferred compensation arrangements, employees, vest over and expire period		vest over four years and expire after seven years
Measurement of initial deferred compensation		$ 9.44
Number of voting common stock authorized to repurchase	800,000
Treasury stock purchased		136,494
Total cost of treasury stock		8,400,000
Treasury stock average price per share		$ 61.54
Research and development costs		34,200,000	19,900,000	23,000,000
Deferred compensation charged (credited) to expense, net of estimated forfeitures				6,600,000
Deferred compensation liability, current		6,400,000
Other Assets [Member]
Basis Of Presentation [Line Items]
Restricted cash		$ 23,800,000
Maximum [Member]
Basis Of Presentation [Line Items]
Cash and cash equivalent maturity term, in days		90
Billed receivable past due term for consideration, in days		60
Minimum [Member]
Basis Of Presentation [Line Items]
Billed receivable past due term for consideration, in days		30