Derivative Instruments and Fair Value Measurements (Details 1) (USD $)	Jun. 30, 2012	Dec. 31, 2011
Derivatives designated for cash flow hedging relationships
Cash Flow Hedge Derivative Instrument Liabilities at Fair Value	$ (6,223,622)	$ (9,486,116)
Designated As Hedging Instrument [Member]
Derivatives designated for cash flow hedging relationships
Cash Flow Hedge Derivative Instrument Liabilities at Fair Value	$ (6,223,622)	$ (9,486,116)

Fair value of all liability derivatives designated as cash flow hedging instruments.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4B

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624163-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 107

-Paragraph 10

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Name:	us-gaap_CashFlowHedgeDerivativeInstrumentLiabilitiesAtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant