Fair Value of Financial Instruments (Details Textual) (USD $)	6 Months Ended
Jun. 30, 2012	Jun. 30, 2011
Fair Value of Financial Instruments (Textual) [Abstract]
Net decrease in the estimated fair value of derivative liabilities	$ 1,469,000	$ 647,000

The increase (decrease) during the period in the carrying value of derivative instruments reported as liabilities that are due to be disposed of within one year (or the normal operating cycle, if longer).

No definition available.

Name:	us-gaap_IncreaseDecreaseInDerivativeLiabilities
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration