Information by Segment and Geographic Area (Details 5) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Information about Product and Services
Revenues from Unaffiliated Customers	$ 3,302,740	$ 3,038,678	$ 2,990,577
Corporate
Information about Product and Services
Revenues from Unaffiliated Customers		180	240
Outsourced, on-site services to steel mills and other metals producers
Information about Product and Services
Revenues from Unaffiliated Customers	1,367,919	1,245,045	1,084,826
Engineered scaffolding, concrete forming and shoring, and other access-related services, rentals and sales
Information about Product and Services
Revenues from Unaffiliated Customers	1,108,293	1,031,807	1,159,200
Railway track maintenance services and equipment
Information about Product and Services
Revenues from Unaffiliated Customers	300,029	313,262	306,016
Resource recovery technologies for the re-use of industrial waste stream by-products
Information about Product and Services
Revenues from Unaffiliated Customers	150,983	148,749	104,028
Air-cooled heat exchangers
Information about Product and Services
Revenues from Unaffiliated Customers	142,960	112,170	129,365
Industrial grating products
Information about Product and Services
Revenues from Unaffiliated Customers	113,388	76,975	92,903
Industrial abrasives and roofing granules
Information about Product and Services
Revenues from Unaffiliated Customers	69,399	67,737	68,244
Heat transfer products
Information about Product and Services
Revenues from Unaffiliated Customers	$ 49,769	$ 42,753	$ 45,755