Cash, Cash Equivalents and Marketable Securities (Details Textuals) (USD $)	9 Months Ended
	Sep. 30, 2011 Year Month Investment
Cash, Cash Equivalents and Marketable Securities (Textuals) [Abstract]
Cash, cash equivalents, and short-term investments held by our foreign subsidiaries	$ 1,210,000,000
Number of investments in unrealized loss position	180
Period for unrealized loss position	less than 12 months
Gross Unrealized Losses	$ 4,000,000