Joint Ventures (Detail) (USD $)	3 Months Ended		6 Months Ended		54 Months Ended		1 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Dec. 31, 2011	Jul. 31, 2012 Capital Contribution To Joint Venture [Member]
Schedule of Equity Method Investments [Line Items]
Accumulated stock-based compensation contributed to joint venture					$ 12,400,000
Consolidated ownership perentage of outstanding equity	58.00%		58.00%		58.00%
Capital contribution			107,300,000	124,263,000	548,000,000		111,000,000
Consolidated share of losses	63.20%	63.20%	63.20%	63.20%
Loss From VCE	59,500,000	46,600,000	115,000,000	88,400,000	368,300,000
Revenue recognized from sales to VCE	72,400,000	22,200,000	141,000,000	44,500,000
Receivable from joint venture	$ 25,600,000		$ 25,600,000		$ 25,600,000	$ 27,000,000