Summary of Significant Accounting Policies (Details Textual)	6 Months Ended
Jun. 30, 2012
Summary of Significant Accounting Policies (Textual) [Abstract]
Vesting period of Restricted stock units	4 years
Restricted Stock Units (RSUs) [Member] \| Maximum [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Vesting period of Restricted stock units	4 years
Restricted Stock Units (RSUs) [Member] \| Minimum [Member]
Summary of Significant Accounting Policies (Textual) [Abstract]
Vesting period of Restricted stock units	2 years

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration