Transactions with Del Taco - Additional Information (Detail)	9 Months Ended
Sep. 30, 2013 Acquisition
Related Party Transactions [Abstract]
Number of other partnerships formed for acquisition	3

Number of other partnerships formed for acquisition.

No definition available.

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Namespace Prefix:	dtipiv_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration