Interest Rate Derivatives - Summary of Partnership's Interest Rate Derivatives, Except for Interest Rate Swaps (Details) - USD ($)		1 Months Ended		12 Months Ended
		Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2017		Dec. 31, 2016
Derivative [Line Items]
Derivative, Fair Value - Asset (Liability)				$ 597,221		$ 383,604
Barclays Bank PLC 4 [Member]
Derivative [Line Items]
Derivative, Purchase Date		2017-09		2017-09
Derivative, Notional Amount				$ 59,935,000
Derivative, Maturity Date				2020-09
Derivative, Effective Capped Rate	[1]			4.00%
Derivative, Index				SIFMA
Derivative, Variable Debt Financing Facility Hedged		M24 TEBS		M24 TEBS	[1]
Derivative, Fair Value - Asset (Liability)				$ 923
Barclays Bank PLC 1 [Member]
Derivative [Line Items]
Derivative, Purchase Date				2014-07		2010-09
Derivative, Notional Amount				$ 30,652,294		$ 29,855,000
Derivative, Maturity Date				2019-08		2017-09
Derivative, Effective Capped Rate	[1]			3.00%		3.00%
Derivative, Index				SIFMA		SIFMA
Derivative, Variable Debt Financing Facility Hedged	[1]			M31 TEBS		M24 TEBS
Derivative, Fair Value - Asset (Liability)				$ 169		$ 2
Royal Bank of Canada-1 [Member]
Derivative [Line Items]
Derivative, Purchase Date				2014-07		2010-09
Derivative, Notional Amount				$ 30,652,294		$ 29,855,000
Derivative, Maturity Date				2019-08		2017-09
Derivative, Effective Capped Rate	[1]			3.00%		3.00%
Derivative, Index				SIFMA		SIFMA
Derivative, Variable Debt Financing Facility Hedged	[1]			M31 TEBS		M24 TEBS
Derivative, Fair Value - Asset (Liability)				$ 169		$ 2
SMBC Capital Markets, Inc-1 [Member]
Derivative [Line Items]
Derivative, Purchase Date				2014-07		2014-02
Derivative, Notional Amount				$ 30,652,294		$ 41,250,000
Derivative, Maturity Date				2019-08		2017-03
Derivative, Effective Capped Rate	[1]			3.00%		1.00%
Derivative, Index				SIFMA		SIFMA
Derivative, Variable Debt Financing Facility Hedged	[1]			M31 TEBS		PHC TOB Trusts
Derivative, Fair Value - Asset (Liability)				$ 169		$ 2
Barclays Bank PLC 3 [Member]
Derivative [Line Items]
Derivative, Purchase Date			2017-06	2017-06
Derivative, Notional Amount				$ 83,000,217
Derivative, Maturity Date				2020-08
Derivative, Effective Capped Rate			1.50%	1.50%	[1]
Derivative, Index				SIFMA
Derivative, Variable Debt Financing Facility Hedged			M33 TEBS	M33 TEBS	[1]
Derivative, Fair Value - Asset (Liability)				$ 425,978
Wells Fargo Bank [Member]
Derivative [Line Items]
Derivative, Purchase Date				2015-07		2015-07
Derivative, Notional Amount				$ 27,666,739		$ 27,940,701
Derivative, Maturity Date				2020-08		2020-08
Derivative, Effective Capped Rate	[1]			3.00%		3.00%
Derivative, Index				SIFMA		SIFMA
Derivative, Variable Debt Financing Facility Hedged	[1]			M33 TEBS		M33 TEBS
Derivative, Fair Value - Asset (Liability)				$ 3,213		$ 93,045
Royal Bank of Canada-2 [Member]
Derivative [Line Items]
Derivative, Purchase Date				2015-07		2014-07
Derivative, Notional Amount				$ 27,666,739		$ 31,028,195
Derivative, Maturity Date				2020-08		2019-08
Derivative, Effective Capped Rate	[1]			3.00%		3.00%
Derivative, Index				SIFMA		SIFMA
Derivative, Variable Debt Financing Facility Hedged	[1]			M33 TEBS		M31 TEBS
Derivative, Fair Value - Asset (Liability)				$ 3,213		$ 34,614
SMBC Capital Markets, Inc-2 [Member]
Derivative [Line Items]
Derivative, Purchase Date				2015-07		2014-07
Derivative, Notional Amount				$ 27,666,739		$ 31,028,195
Derivative, Maturity Date				2020-08		2019-08
Derivative, Effective Capped Rate	[1]			3.00%		3.00%
Derivative, Index				SIFMA		SIFMA
Derivative, Variable Debt Financing Facility Hedged	[1]			M33 TEBS		M31 TEBS
Derivative, Fair Value - Asset (Liability)				$ 3,213		$ 34,614
Barclays Bank PLC 2 [Member]
Derivative [Line Items]
Derivative, Purchase Date			2017-06	2017-06		2014-07
Derivative, Notional Amount				$ 91,956,883		$ 31,028,195
Derivative, Maturity Date				2019-08		2019-08
Derivative, Effective Capped Rate			1.50%	1.50%	[1]	3.00%	[1]
Derivative, Index				SIFMA		SIFMA
Derivative, Variable Debt Financing Facility Hedged			M31 TEBS	M31 TEBS	[1]	M31 TEBS	[1]
Derivative, Fair Value - Asset (Liability)				$ 160,174		$ 34,614
Bank of New York Mellon [Member]
Derivative [Line Items]
Derivative, Purchase Date						2010-09
Derivative, Notional Amount						$ 29,855,000
Derivative, Maturity Date						2017-09
Derivative, Effective Capped Rate	[1]					3.00%
Derivative, Index						SIFMA
Derivative, Variable Debt Financing Facility Hedged	[1]					M24 TEBS
Derivative, Fair Value - Asset (Liability)						$ 2
Deutsche Bank [Member]
Derivative [Line Items]
Derivative, Purchase Date						2013-08
Derivative, Notional Amount						$ 89,565,000
Derivative, Maturity Date						2017-09
Derivative, Effective Capped Rate	[1]					1.50%
Derivative, Index						SIFMA
Derivative, Variable Debt Financing Facility Hedged	[1]					M24 TEBS
Derivative, Fair Value - Asset (Liability)						$ 619
Royal Bank of Canada-3 [Member]
Derivative [Line Items]
Derivative, Purchase Date						2015-07
Derivative, Notional Amount						$ 27,940,701
Derivative, Maturity Date						2020-08
Derivative, Effective Capped Rate	[1]					3.00%
Derivative, Index						SIFMA
Derivative, Variable Debt Financing Facility Hedged	[1]					M33 TEBS
Derivative, Fair Value - Asset (Liability)						$ 93,045
SMBC Capital Markets, Inc-3 [Member]
Derivative [Line Items]
Derivative, Purchase Date						2015-07
Derivative, Notional Amount						$ 27,940,701
Derivative, Maturity Date						2020-08
Derivative, Effective Capped Rate	[1]					3.00%
Derivative, Index						SIFMA
Derivative, Variable Debt Financing Facility Hedged	[1]					M33 TEBS
Derivative, Fair Value - Asset (Liability)						$ 93,045

[1] For additional details, see Note 25 to the Partnership's condensed consolidated financial statements.