Variable Interest Entities (Balances Related to Joint Ventures) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015
Variable Interest Entity, Not Primary Beneficiary, Disclosures [Abstract]
Maximum Guarantee Exposure for Joint Venture Loans	$ 71.7

Maximum Guarantee Exposure for Joint Venture Loans

No definition available.

Name:	dre_MaximumGuaranteeExposureForJointVentureLoans
Namespace Prefix:	dre_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant