Debt Financing Footnote XBRL details (Details) - USD ($)	Mar. 31, 2016	Dec. 31, 2015
Debt financing	$ 430,307,422	$ 451,496,716
M33 TEBS Financing [Member]
Restricted Cash and Cash Equivalents	4,900,000	4,800,000
M31 TEBS Financing [Member]
Restricted Cash and Cash Equivalents	146,000	163,000
M24 TEBS Financing [Member]
Restricted Cash and Cash Equivalents	35,100	365,000
Interest Rate Swaps [Member]
Cash Collateral for Borrowed Securities	$ 2,200,000	$ 1,500,000

The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restrictions may include legally restricted deposits held as compensating balances against borrowing arrangements, contracts entered into with others, or entity statements of intention with regard to particular deposits; however, time deposits and short-term certificates of deposit are not generally included in legally restricted deposits. Excludes compensating balance arrangements that are not agreements which legally restrict the use of cash amounts shown on the balance sheet. This element is for unclassified presentations; for classified presentations there is a separate and distinct element.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.1)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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