Summary of Significant Accounting Policies (Basic and Diluted Income) (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net Income (Loss) Available to Common Stockholders, Basic	$ 188,419	$ 165,269	$ 1,210,543	$ 70,200	$ 47,755	$ 112,014	$ 109,067	$ 43,307	$ 1,634,431	$ 312,143	$ 615,310
Participating Securities, Distributed and Undistributed Earnings (Loss), Basic									(3,981)	(2,356)	(3,081)
Net Income Loss Attributable To Common Stockholders Basic									1,630,450	309,787	612,229
Participating Securities, Distributed and Undistributed Earnings (Loss), Diluted									3,981	2,356	3,081
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Redeemable									15,176	3,089	6,404
Net Income (Loss) Available to Common Stockholders, Diluted									$ 1,649,607	$ 315,232	$ 621,714
Weighted Average Number of Shares Outstanding, Basic	356,204	355,905	355,647	355,282	354,711	351,856	347,464	345,665	355,762	349,942	345,057
Weighted Average Limited Partnership Units Outstanding, Basic									3,303	3,481	3,582
Weighted Average Number Diluted Shares Outstanding Adjustment									2,946	3,653	3,558
Weighted Average Number of Shares Outstanding, Diluted	360,244	362,102	361,981	360,700	359,024	358,981	354,433	349,674	362,011	357,076	352,197
Duke Realty Limited Partnership [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net Income (Loss) Available to Common Stockholders, Basic	$ 190,168	$ 166,804	$ 1,221,783	$ 70,852	$ 48,174	$ 113,145	$ 110,168	$ 43,745	$ 1,649,607	$ 315,232	$ 621,714
Participating Securities, Distributed and Undistributed Earnings (Loss), Basic									(3,981)	(2,356)	(3,081)
Net Income Loss Attributable To Common Unitholders Basic									1,645,626	312,876	618,633
Participating Securities, Distributed and Undistributed Earnings (Loss), Diluted									3,981	2,356	3,081
Diluted Net Income Loss Attributable To Common Unitholders									$ 1,649,607	$ 315,232	$ 621,714
Weighted Average Number of Shares Outstanding, Basic	359,491	359,206	358,952	358,598	358,135	355,351	350,968	349,163	359,065	353,423	348,639
Weighted Average Number Diluted Shares Outstanding Adjustment									2,946	3,653	3,558
Weighted Average Number of Shares Outstanding, Diluted	360,244	362,102	361,981	360,700	359,024	358,981	354,433	349,674	362,011	357,076	352,197