Reclassifications out of Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amount reclassified from AOCL to Interest expense, net of capitalized interest	$ (540.1)	$ (496.5)	$ (1,114.8)	$ (1,058.5)
Amount reclassified from AOCL to Write-downs, reserves, and project opening costs, net of recoveries	(23.4)	(7.9)	(44.1)	(24.1)
Amount reclassified from AOCL to Loss/(income) from discontinued operations	(0.3)	(84.4)	(44.2)	(70.2)
Related tax impact	115.7	105.9	406.0	264.2
Reclassification, net of income taxes	(209.2)	(241.8)	(426.2)	(522.9)
Defined Benefit Plan Adjustments [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amount reclassified from AOCL to Interest expense, net of capitalized interest	0.2		0.4
Amount reclassified from AOCL to Write-downs, reserves, and project opening costs, net of recoveries	0		0
Amount reclassified from AOCL to Loss/(income) from discontinued operations	0		0
Related tax impact	0		(0.1)
Reclassification, net of income taxes	0.2		0.3
Foreign Currency Translation Adjustments [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amount reclassified from AOCL to Interest expense, net of capitalized interest	0		0
Amount reclassified from AOCL to Write-downs, reserves, and project opening costs, net of recoveries	0		(4.1)
Amount reclassified from AOCL to Loss/(income) from discontinued operations	0		(2.2)
Related tax impact	0		0
Reclassification, net of income taxes	0		(6.3)
Losses on Derivative Instruments [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amount reclassified from AOCL to Interest expense, net of capitalized interest	0	7.2	3.9	14.3
Amount reclassified from AOCL to Write-downs, reserves, and project opening costs, net of recoveries	0		0
Amount reclassified from AOCL to Loss/(income) from discontinued operations	0		0
Related tax impact	0	(2.6)	(1.4)	(5.2)
Reclassification, net of income taxes	$ 0	$ 4.6	$ 2.5	$ 9.1