Commitments And Contingencies (Other Contingencies) (Detail)		3 Months Ended			12 Months Ended
	Aug. 08, 2014 USD ($)	Sep. 30, 2014 USD ($)	Dec. 31, 2011 USD ($)	Dec. 31, 2008 USD ($)	Dec. 31, 2014	Dec. 31, 2013 USD ($) Homeowner	Dec. 31, 2011 Homeowner Home	Jun. 30, 2015 USD ($)	Dec. 31, 2012 acre	Apr. 15, 2011 Homeowner	Dec. 31, 2007 USD ($)	Jul. 31, 2006
Loss Contingencies [Line Items]
Airplane operating lease period, years
Fair Value Of Residual Value Guarantee		$ 7,800,000
Fair Value Of Residual Value Guarantee, Fair Value of Operating Lease Asset Threshold		9,500,000
Environmental Claims For A Site In Goodyear Arizona
Loss Contingencies [Line Items]
Estimated liability				$ 65,200,000				$ 72,000,000			$ 41,500,000
Amount of additional remediation activities		49,000,000	$ 30,300,000	$ 24,300,000
Accrued environmental loss contingencies current								15,500,000
Loss contingency reimbursement rate												21.00%
Other receivables								$ 15,500,000
Environmental Claims For Crab Orchard National Wildlife Refuge Superfund Site
Loss Contingencies [Line Items]
Approximate size of referenced site, acres | acre									55,000
amount paid into escrow						$ 166,667
Environmental Claims For Site In Roseland New Jersey
Loss Contingencies [Line Items]
Amount of additional remediation activities		$ 6,800,000
Approximate number of homes tested for contaminants | Home							40
Number of Homes Where Contaminants Were Found | Home							3
Homeowners Filing Suits Against Company | Homeowner						139				3
Homes Suing Company Where Vapor Mitigation Equipment Was Installed | Homeowner						3
Loss Contingency, Damages Paid, Value	$ 6,500,000
Number Of Tenants Who Filed Separate Lawsuit | Homeowner										1
Number of members in the purported class | Homeowner							138