Commitments and Contingencies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended				6 Months Ended	9 Months Ended							3 Months Ended								0 Months Ended	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Jun. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2013 SunEdison [Member]	Mar. 31, 2013 SunEdison [Member] Maximum [Member]	Sep. 30, 2013 Contract Termination [Member]	Sep. 30, 2013 Purchase Obligation Termination [Member]	Mar. 31, 2013 Purchase Obligation Termination [Member]	Sep. 30, 2013 2011 Global Plan [Member]	Dec. 31, 2012 2011 Global Plan [Member]	Sep. 30, 2013 2011 Global Plan [Member] Contract Termination [Member]	Dec. 31, 2012 2011 Global Plan [Member] Contract Termination [Member]	Sep. 30, 2013 SMP JV [Member]	Mar. 31, 2013 SMP JV [Member]	Sep. 04, 2012 Purchase Obligation Termination [Member]	Sep. 30, 2013 Purchase Obligation Termination [Member]	Dec. 31, 2012 Purchase Obligation Termination [Member]
Loss Contingencies [Line Items]
Net loss attributable to SunEdison stockholders	$ (108.0)	$ 37.0	$ 77.2	$ 98.6	$ 175.8	$ (300.3)	$ (138.8)
Equity Method Investment, Ownership Percentage	8.20%					8.20%													50.00%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners	91.80%					91.80%														50.00%
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	40.6					40.6													96.9
Equity Method Investments																			175.0
Litigation Settlement, Gross																					70.0
Payments for Legal Settlements													20.0	10.0								15.0	25.0
Customer and other deposits	165.4					165.4			184.5											60.2
Equity Method Investment, Aggregate Cost																				0
Restructuring Reserve												40.1			96.8	204.5	40.1	134.5
Restructuring Reserve, Current												9.7
Restructuring Reserve, Noncurrent												30.4
Loss Contingency, Range of Possible Loss, Maximum													166.0
Business Acquisition, Contingent Consideration, at Fair Value	26.8					26.8				50.4
Contingent consideration related to acquisitions	26.8					26.8		26.8	23.1
Business Acquisition, Contingent Consideration, at Fair Value, Noncurrent								23.6
Business Acquisition, Contingent Consideration, Potential Cash Payment											$ 84.3