Real Estate (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		9 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Sep. 30, 2019	Dec. 31, 2019
Real Estate Owned, Disclosure of Detailed Components [Abstract]
Land	$ 1,758,946		$ 1,758,946			$ 1,767,029
Building and tenant improvements	7,823,236		7,823,236			7,741,607
Lease intangibles	595,771		595,771			614,964
Real estate, gross	10,177,953		10,177,953			10,123,600
Accumulated depreciation and amortization	(2,581,127)		(2,581,127)			(2,481,250)
Total	7,596,826		7,596,826			7,642,350
Accrued capital expenditures and tenant improvements			28,900		$ 46,900
Accumulated amortization	525,800		525,800			533,100
Intangible liabilities relating to below-market leases	362,300		362,300			372,100
Accumulated amortization on below-market leases	266,700		266,700			267,100
Below-market lease intangible amortization	4,000	$ 4,700	8,200	$ 9,600
Amortization of intangible assets	4,900	$ 6,300	10,400	$ 12,800
Leases, acquired-in-place
Real Estate Owned, Disclosure of Detailed Components [Abstract]
In-place lease value	537,200		537,200			554,900
In-place lease amortization expense
2020 (remaining six months)	8,291		8,291
2021	13,202		13,202
2022	9,197		9,197
2023	6,675		6,675
2024	5,008		5,008
Above market leases
Real Estate Owned, Disclosure of Detailed Components [Abstract]
Above market leases	58,600		58,600			$ 60,100
Below-market lease accretion (income), net of above-market lease amortization expense
Below-market lease accretion (income), net of above-market lease amortization expense
2020 (remaining six months)	(6,506)		(6,506)
2021	(11,520)		(11,520)
2022	(9,541)		(9,541)
2023	(8,188)		(8,188)
2024	$ (7,651)		$ (7,651)