Commitments, Contingent Liabilities and Other Matters (Details 4) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010
Board Of Directors
Executive Agreements
Number of Board approved executive employment agreements	9
Number of officers having outstanding non-interest bearing relocation home loans	3
Repayment tenure of non-interest bearing relocation home loans (in years)	20
Amount of relocation home loans	$ 4.5
Board Of Directors | Maximum
Executive Agreements
Period of rolling term of employment agreements (in years)	2
Board Of Directors | Minimum
Executive Agreements
Period of rolling term of employment agreements (in years)	1
Consortium arrangements | Thermal Equipment and Services reportable segment
Collaborative Arrangements
Entity's share of the aggregate contract value on open consortium arrangements	324.0	381.4
Percentage of entity's share of the aggregate contract value, recognized as revenue	56.00%	45.00%
Aggregate contract value on open consortium arrangements	801.1	948.7
Estimated fair value of potential obligation recorded as a liabilities	$ 1.9	$ 3.2