Investments in Unconsolidated Companies (Narrative) (Details)	Dec. 31, 2013 entities
Equity Method Investments and Joint Ventures [Abstract]
Number of unconsolidated joint ventures in which equity interests held	19

Number of Unconsolidated Joint Ventures in which Equity Interests Held

No definition available.

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Namespace Prefix:	dre_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant