Fair Value Measurements (Fair Value Option) (Details) (Eris [Member]) In Millions, except Share data, unless otherwise specified	0 Months Ended
	Sep. 07, 2011 USD ($)	Sep. 07, 2011 TWD	Dec. 31, 2011
Fair Value Option Quantitative Disclosures [Line Items]
Number Of Common Stock Shares Purchased			12,413,604
Price Paid Per Common Stock Share		39
Amount Paid For Common Stock Shares	$ 14	390
Percentage Of Ownership	30.00%	30.00%
Sale of Stock, Number of Shares Issued in Transaction	10,000,000	10,000,000