Commitments And Contingencies (Asbestos Liability) (Detail) (USD $)	9 Months Ended			3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Sep. 30, 2012 Asbestos Commitments and Contingencies LegalMatter	Sep. 30, 2011 Asbestos Commitments and Contingencies	Sep. 30, 2012 Asbestos Commitments and Contingencies LegalMatter	Sep. 30, 2011 Asbestos Commitments and Contingencies	Dec. 31, 2011 Asbestos Commitments and Contingencies	Dec. 31, 2010 Asbestos Commitments and Contingencies	Dec. 31, 2009 Asbestos Commitments and Contingencies	Jun. 30, 2012 Asbestos Commitments and Contingencies	Jun. 30, 2011 Asbestos Commitments and Contingencies	Jul. 14, 2008 Joseph Norris Asbestos Commitments and Contingencies Year	Jun. 30, 2009 Earl Haupt Asbestos Commitments and Contingencies	Mar. 14, 2008 James Baccus Asbestos Commitments and Contingencies	May 16, 2008 Chief Brewer Asbestos Commitments and Contingencies	Feb. 23, 2011 James Nelson Asbestos Commitments and Contingencies	Mar. 23, 2010 James Nelson Asbestos Commitments and Contingencies	Feb. 23, 2011 Larry Bell Asbestos Commitments and Contingencies	Mar. 23, 2010 Larry Bell Asbestos Commitments and Contingencies	Aug. 21, 2012 Ronald Dummitt Asbestos Commitments and Contingencies	Aug. 17, 2011 Ronald Dummitt Asbestos Commitments and Contingencies	Mar. 09, 2012 Frank Paasch Asbestos Commitments and Contingencies	Feb. 02, 2009 Dennis Woodard Asbestos Commitments and Contingencies	Aug. 29, 2012 William Paulus Asbestos Commitments and Contingencies	Sep. 30, 2012 New York Asbestos Commitments and Contingencies	Sep. 30, 2012 Mississippi Asbestos Commitments and Contingencies	Sep. 30, 2012 Texas Asbestos Commitments and Contingencies	Sep. 30, 2012 Ohio Asbestos Commitments and Contingencies
Loss Contingencies [Line Items]
Plaintiff's Request																					$ 4,900,000				$ 800,000
Court written decision																					8,000,000
Pending claims				56,773	58,572	56,773	58,572	58,658	64,839		57,559	56,403														19,300	5,500	9,900	5,400
Number of judgments paid				2		2
Number of years after judgment paid, years													2
Jury verdict payment including accrued judgment interest													2,540,000
Jury verdict payment														20,000
Compensatory damages															2,450,000
Additional damages															11,900,000
Court judgment																680,000			200,000					1,650,000
Jury verdict percentage of responsibility.																						99.00%		0.50%
Jury verdict																		14,500,000		3,500,000		32,000,000	123,000	16,930,000	6,900,000
Share Of Responsibility Of Verdict																		9.09%		5.00%			12.50%		10.00%
Court judgment against all parties held responsible																	4,000,000
Additional interest on the compensation awarded																	10,000
Gross settlement and defense costs						73,500,000	82,900,000
Payments for asbestos-related fees and costs, net of insurance recoveries	(60,051,000)	(59,233,000)		20,800,000	23,600,000	60,100,000	59,200,000	79,300,000
Cumulative claims resolved				89,000		89,000
Settlement cost				360,000,000		360,000,000
Average settlement cost per resolved claim								4,123	7,036	4,781
Cumulative average settlement cost per resolved claim				4,000		4,000
Number of years included in methodology base reference period				2		2
Additional quarters included in methodology base reference period				3		3
Estimated payments to current and future claimants				30,000,000,000		30,000,000,000
Additional liability								285,000,000
Percentage of mesothelioma claims of total pending asbestos claims								8.00%
Percentage of mesothelioma claims of aggregate settlement and defense costs								90.00%
Liability for claims				824,000,000		824,000,000		894,000,000
Percentage Of Asbestos Liability Attributable To Settlement And Denfese Costs For Future Claims								80.00%
Current portion of total estimated liability	100,943,000		100,943,000	101,000,000		101,000,000
Number of coverage in place agreements with excess insurer groups				11		11
Number of buyout agreements with excess insurer groups				6		6
Aggregate value of policy buyout agreements				79,500,000		79,500,000
Forecasted percentage of liability that would be reimbursed by insurers								25.00%
Insurance reimbursement asset				$ 216,000,000		$ 216,000,000		$ 225,000,000