Cash Equivalents and Investments (Details Textual) (USD $)	9 Months Ended
Sep. 30, 2012
Cash Equivalents and Investments (Additional Textual) [Abstract]
Significant realized gains or losses on available-for-sale securities	0
Available-for-sale securities held	0
Maximum [Member]
Cash Equivalents and Investments (Textual) [Abstract]
Maturity Period Available-for-sale securities	2 years
Minimum [Member]
Cash Equivalents and Investments (Textual) [Abstract]
Unrealized loss position	12 months

The net amount of gross unrealized gains (losses) for securities, at a point in time, which are categorized neither as held-to-maturity nor trading securities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=6872113&loc=d3e27357-111563

Name:	us-gaap_AvailableForSaleSecuritiesGrossUnrealizedGainLoss
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant