Summary of Significant Accounting Policies (Basic and Diluted Income) (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net Income (Loss) Available to Common Stockholders, Basic	$ 86,802	$ 226,566	$ 71,053	$ 44,551	$ 63,896	$ 53,025	$ 193,845	$ 72,963	$ 428,972	$ 383,729	$ 1,634,431
Participating Securities, Distributed and Undistributed Earnings (Loss), Basic									(1,487)	(1,675)	(3,981)
Net Income Loss Attributable To Common Stockholders Basic									427,485	382,054	1,630,450
Participating Securities, Distributed and Undistributed Earnings (Loss), Diluted									1,487	1,675	3,981
Noncontrolling Interest in Net Income (Loss) Operating Partnerships, Redeemable									3,678	3,528	15,176
Net Income (Loss) Available to Common Stockholders, Diluted									$ 432,650	$ 387,257	$ 1,649,607
Weighted Average Number of Shares Outstanding, Basic	367,603	362,416	359,681	359,139	358,561	357,898	357,054	356,740	362,234	357,569	355,762
Weighted Average Limited Partnership Units Outstanding, Basic									3,118	3,290	3,303
Weighted Average Number Diluted Shares Outstanding Adjustment									1,987	2,438	2,946
Weighted Average Number of Shares Outstanding, Diluted	372,464	367,271	362,926	362,362	362,536	361,410	362,741	360,400	367,339	363,297	362,011
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	$ 87,509	$ 228,534	$ 71,674	$ 44,933	$ 64,422	$ 53,520	$ 195,669	$ 73,646	$ 432,650	$ 387,257	$ 1,649,607
Participating Securities, Distributed and Undistributed Earnings (Loss), Basic									(1,487)	(1,675)	(3,981)
Net Income Loss Attributable To Common Unitholders Basic									431,163	385,582	1,645,626
Participating Securities, Distributed and Undistributed Earnings (Loss), Diluted									1,487	1,675	3,981
Diluted Net Income Loss Attributable To Common Unitholders									$ 432,650	$ 387,257	$ 1,649,607
Weighted Average Number of Shares Outstanding, Basic	370,725	365,558	362,826	362,204	361,672	361,200	360,447	360,095	365,352	360,859	359,065
Weighted Average Number Diluted Shares Outstanding Adjustment									1,987	2,438	2,946
Weighted Average Number of Shares Outstanding, Diluted	372,464	367,271	362,926	362,362	362,536	361,410	362,741	360,400	367,339	363,297	362,011