Accounts Receivable And Contracts In Progress (Components Of Contracts In Progress) (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Costs and earnings in excess of billings on contracts in progress	$ 49,508	$ 21,142
Costs and earnings in excess of billings for completed contracts	1,381	7,459
Total contract revenues in excess of billings	50,889	28,601
Current portion of contract revenues in excess of billings	50,889	26,412
Portion included in other noncurrent assets		2,189
Total billings in excess of contract revenues	(19,999)	(13,627)
Costs And Earnings In Excess Of Billings [Member]
Costs and earnings for contracts in progress	366,985	173,187
Amounts billed	(317,477)	(152,045)
Billings In Excess Of Costs And Earnings [Member]
Costs and earnings for contracts in progress	363,048	414,170
Amounts billed	$ (383,047)	$ (427,797)