Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net income	$ 432,644	$ 387,268	$ 1,654,341
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation of buildings and tenant improvements	272,422	256,250	242,606
Amortization of deferred leasing and other costs	54,801	55,967	56,866
Amortization of deferred financing costs	6,536	5,867	5,402
Straight-line rental income and expense, net	(21,197)	(24,605)	(16,051)
Impairment charges	0	0	4,481
Loss on debt extinguishment	6,320	388	26,104
Gain on involuntary conversion	2,259	0	0
Gains on land and property sales	(242,543)	(219,114)	(1,480,691)
Third-party construction contracts, net	9,254	(15,400)	1,000
Other accrued revenues and expenses, net	8,476	47,711	3,104
Equity in earnings in excess of operating distributions received from unconsolidated joint ventures	(18,556)	(9,925)	(46,958)
Net cash provided by operating activities	505,898	484,407	450,204
Cash flows from investing activities:
Development of real estate investments	(446,801)	(577,383)	(549,563)
Acquisition of buildings and related intangible assets	(210,224)	(348,107)	(982,598)
Acquisition of land and other real estate assets	(388,202)	(244,262)	(243,846)
Second generation tenant improvements, leasing costs and building improvements	(47,549)	(53,474)	(52,554)
Other deferred leasing costs	(38,509)	(39,380)	(30,208)
Other assets	(10,777)	(14,535)	(6,960)
Proceeds from the repayments of notes receivable from property sales	162,550	154,107	3,650
Proceeds from land and property sales, net	432,662	511,391	2,523,358
Capital distributions from unconsolidated joint ventures	26,272	23,133	124,956
Capital contributions and advances to unconsolidated joint ventures	(34,496)	(5,920)	(10,323)
Net cash (used for) provided by investing activities	(555,074)	(594,430)	775,912
Cash flows from financing activities:
Proceeds from issuance of common shares, net	272,761	34,913	13,383
Proceeds from unsecured debt	582,284	450,000	300,000
Payments on unsecured debt	(255,812)	(7,190)	(692,137)
Payments on secured indebtedness including principal amortization	(45,515)	(232,234)	(72,648)
(Repayments) borrowings on line of credit, net	(30,000)	30,000	(48,000)
Distributions to common shareholders - regular	(318,702)	(291,502)	(273,999)
Distributions to common shareholders - special	0	0	(302,833)
Contributions from (distributions to) noncontrolling interests, net	(2,648)	(2,456)	(11,882)
Tax payments on stock-based compensation awards	(6,825)	(8,459)	(14,946)
Change in book overdrafts	138	(22,088)	22,924
Cash settlement of interest rate swaps	(35,569)	0	0
Other financing activities	(10,183)	0	0
Deferred financing costs	(4,839)	(9,071)	(8,931)
Redemption of Limited Partner Units	0	0	(457)
Net cash provided by (used for) financing activities	145,090	(58,087)	(1,089,526)
Net increase (decrease) in cash, cash equivalents and restricted cash	95,914	(168,110)	136,590
Cash, cash equivalents and restricted cash at beginning of year	(25,517)	(193,627)	(57,037)
Cash, cash equivalents and restricted cash at end of year	121,431	25,517	193,627
Non-cash investing and financing activities:
Liabilities and right-of-use assets - operating leases	40,467	0	0
Carrying amount of pre-existing ownership interest in acquired property	0	5,034	0
Non-cash property contribution from noncontrolling interests	0	3,200	0
Notes receivable from buyers in property sales	0	0	404,846
Conversion of Limited Partner Units to common shares	1,624	(269)	1,847
Duke Realty Limited Partnership [Member]
Cash flows from operating activities:
Net income	432,644	387,268	1,654,341
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation of buildings and tenant improvements	272,422	256,250	242,606
Amortization of deferred leasing and other costs	54,801	55,967	56,866
Amortization of deferred financing costs	6,536	5,867	5,402
Straight-line rental income and expense, net	(21,197)	(24,605)	(16,051)
Impairment charges	0	0	4,481
Loss on debt extinguishment	6,320	388	26,104
Gain on involuntary conversion	2,259	0	0
Gains on land and property sales	(242,543)	(219,114)	(1,480,691)
Third-party construction contracts, net	9,254	(15,400)	1,000
Other accrued revenues and expenses, net	8,476	47,711	3,104
Equity in earnings in excess of operating distributions received from unconsolidated joint ventures	(18,556)	(9,925)	(46,958)
Net cash provided by operating activities	505,898	484,407	450,204
Cash flows from investing activities:
Development of real estate investments	(446,801)	(577,383)	(549,563)
Acquisition of buildings and related intangible assets	(210,224)	(348,107)	(982,598)
Acquisition of land and other real estate assets	(388,202)	(244,262)	(243,846)
Second generation tenant improvements, leasing costs and building improvements	(47,549)	(53,474)	(52,554)
Other deferred leasing costs	(38,509)	(39,380)	(30,208)
Other assets	(10,777)	(14,535)	(6,960)
Proceeds from the repayments of notes receivable from property sales	162,550	154,107	3,650
Proceeds from land and property sales, net	432,662	511,391	2,523,358
Capital distributions from unconsolidated joint ventures	26,272	23,133	124,956
Capital contributions and advances to unconsolidated joint ventures	(34,496)	(5,920)	(10,323)
Net cash (used for) provided by investing activities	(555,074)	(594,430)	775,912
Cash flows from financing activities:
Contributions from the General Partner	272,761	34,913	13,383
Proceeds from unsecured debt	582,284	450,000	300,000
Payments on unsecured debt	(255,812)	(7,190)	(692,137)
Payments on secured indebtedness including principal amortization	(45,515)	(232,234)	(72,648)
(Repayments) borrowings on line of credit, net	(30,000)	30,000	(48,000)
Distributions to common shareholders - regular	(321,469)	(294,233)	(276,539)
Distributions to common shareholders - special	0	0	(305,628)
Contributions from (distributions to) noncontrolling interests, net	119	275	(6,547)
Tax payments on stock-based compensation awards	(6,825)	(8,459)	(14,946)
Change in book overdrafts	138	(22,088)	22,924
Cash settlement of interest rate swaps	(35,569)	0	0
Other financing activities	(10,183)	0	0
Deferred financing costs	(4,839)	(9,071)	(8,931)
Redemption of Limited Partner Units	0	0	(457)
Net cash provided by (used for) financing activities	145,090	(58,087)	(1,089,526)
Net increase (decrease) in cash, cash equivalents and restricted cash	95,914	(168,110)	136,590
Cash, cash equivalents and restricted cash at beginning of year	(25,517)	(193,627)	(57,037)
Cash, cash equivalents and restricted cash at end of year	121,431	25,517	193,627
Non-cash investing and financing activities:
Liabilities and right-of-use assets - operating leases	40,467	0	0
Carrying amount of pre-existing ownership interest in acquired property	0	5,034	0
Non-cash property contribution from noncontrolling interests	0	3,200	0
Notes receivable from buyers in property sales	0	0	404,846
Conversion of Limited Partner Units to common shares	$ 1,624	$ (269)	$ 1,847