Litigation and Uncertainties (Narrative) (Details) (USD $)		3 Months Ended		9 Months Ended		12 Months Ended				36 Months Ended
	Sep. 30, 2011 United Kingdom [Member] claims	Sep. 30, 2011 United States [Member] claims	Sep. 30, 2010 United States [Member] claims	Sep. 30, 2011 United States [Member] claims	Sep. 30, 2010 United States [Member] claims	Dec. 31, 2010 United States [Member] claims	Jun. 30, 2011 United States [Member] claims	Jun. 30, 2010 United States [Member] claims	Dec. 31, 2009 United States [Member] claims	Dec. 26, 2008 Power Plant Dispute Ireland [Member]	Sep. 30, 2011 Power Plant Arbitration North America [Member]	Sep. 30, 2011 Environmental Matters [Member]
Asbestos related open claims number	296	124,540	124,360	124,540	124,360	124,420	123,990	122,490	125,100
Asbestos litigation, defense and case resolution payments		$ 12,100,000	$ 15,300,000	$ 48,700,000	$ 49,300,000
Provision for revaluation		1,987,000	5,319,000	5,987,000	13,908,000
Total cumulative indemnity costs paid through the balance sheet date		758,600,000		758,600,000
Total cumulative defense costs paid through the balance sheet date		360,100,000		360,100,000
Portion of total defense and indemnity costs that represent defense costs		32.00%		32.00%
Historic average combined indemnity and defense cost per resolved claim		3,100		3,100
Expected cash outflows as a result of asbestos liability indemnity and defense payment in excess of issuance settlement proceeds				(6,100,000)
Average per claim indemnity increase rate						25.00%
Estimated impact on the asbestos related liability from an increase of 25% in the average per claim indemnity settlement amount						52,300,000
Percentage of the asbestos related liability reserve that would result in an additional expense to be recognized in the statement of operations for a 25% increase in the average asbestos-related claim indemnity settlement amount and assuming no change in the assumptions currently used to estimate the asbestos-related insurance asset						80.00%
Number of asbestos claims brought against United Kingdom	989
Asbestos related liability upon pleural plaque ruling	52,900,000
Aggregate charges recorded related to claims										61,700,000
Retention monies held by client											17,800,000
Letter of credit held by client											82,000,000
Excess owed under purchase order as a result of alleged failures											47,500,000
Aggregate potential liability, maximum												500,000
Estimates of the cost of installing additional control equipment												$ 30,000,000