The amount of ownership interest of different classes of partners in limited partnership.

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Article 3

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.3-04)

-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 272

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70478-108055

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 272

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055

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

Income Taxes - Reconciliation of Partnership Equity Per Financial Statements to Partners' Equity for Tax Purposes (Detail) (USD $)	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Partners' equity per financial statements	$ 2,042,619us-gaap_PartnersCapital	$ 2,073,492us-gaap_PartnersCapital	$ 2,092,095us-gaap_PartnersCapital	$ 2,103,075us-gaap_PartnersCapital
Issue costs of limited partnership units capitalized for tax purposes	637,325
Difference in book vs. tax depreciation	79,717
Other	235us-gaap_OtherPartnersCapital
Partners' equity for tax purposes	$ 2,759,896dtrpi_PartnersEquityNet