Reclassifications out of Accumulated Other Comprehensive Loss (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Amount reclassified from AOCL to Interest expense, net of capitalized interest	$ (563.0)	$ (515.8)	$ (1,677.7)	$ (1,574.3)
Amount reclassified from AOCL to Write-downs, reserves, and project opening costs, net of recoveries	(0.5)	(32.8)	(44.7)	(56.9)
Amount reclassified from AOCL to Loss/(income) from discontinued operations	14.9	0.8	(29.3)	(69.4)
Related tax impact	413.4	225.3	819.3	489.5
Reclassification, net of income taxes	(761.8)	(503.4)	(1,187.8)	(1,026.3)
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		0.6
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	(0.1)		(0.2)
Reclassification, net of income taxes	0.1		0.4
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	6.9	3.9	21.2
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	(2.5)	(1.4)	(7.7)
Reclassification, net of income taxes	$ 0	$ 4.4	$ 2.5	$ 13.5