Net Income (Loss) Per Common Share Reconciling the Components of Basic and Diluted Net Income (Loss) per Common Share (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income attributable to common shareholders	$ 53,025	$ 165,269	$ 319,833	$ 1,446,012
Less: dividends on participating securities	(394)	(444)	(1,249)	(1,527)
Basic net income attributable to common shareholders	52,631	164,825	318,584	1,444,485
Add back dividends on dilutive participating securities	0	444	1,249	1,527
Noncontrolling interest in earnings of common unitholders	495	1,535	3,002	13,427
Diluted net income attributable to common shareholders	$ 53,126	$ 166,804	$ 322,835	$ 1,459,439
Weighted average number of common shares/units outstanding, Basic	357,898	355,905	357,235	355,614
Weighted average Limited Partner Units outstanding	3,302	3,301	3,350	3,307
Other potential dilutive shares/units	210	2,896	2,160	3,026
Weighted average number of common shares/units and potential dilutive securities	361,410	362,102	362,745	361,947
Duke Realty Limited Partnership [Member]
Earnings Per Share, Basic, by Common Class, Including Two Class Method [Line Items]
Net income attributable to common shareholders	$ 53,520	$ 166,804	$ 322,835	$ 1,459,439
Less: dividends on participating securities	(394)	(444)	(1,249)	(1,527)
Basic net income attributable to common unitholders	53,126	166,360	321,586	1,457,912
Add back dividends on dilutive participating securities	0	444	1,249	1,527
Diluted net income attributable to common unitholders	$ 53,126	$ 166,804	$ 322,835	$ 1,459,439
Weighted average number of common shares/units outstanding, Basic	361,200	359,206	360,585	358,921
Other potential dilutive shares/units	210	2,896	2,160	3,026
Weighted average number of common shares/units and potential dilutive securities	361,410	362,102	362,745	361,947