Leases ASC 842 (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($)	Sep. 30, 2019 USD ($) propertyUnit
Lessor Disclosure [Abstract]
Rental and other revenues related to operating lease payments	$ 184,200	$ 534,200
Variable lease income	17,300	49,200
Operating leases, scheduled future minimum payments receivable [Abstract]
October 1 to December 31, 2019	156,920	156,920
2020	619,066	619,066
2021	577,843	577,843
2022	544,683	544,683
2023	483,709	483,709
2024	422,362	422,362
Thereafter	1,820,576	1,820,576
Operating leases, total future minimum payments receivable due	$ 4,625,159	$ 4,625,159
Lessee Disclosure [Abstract]
Number of properties subject to ground leases | propertyUnit		20
Weighted average remaining term of ground leases (in years)	52 years	52 years
Operating lease liability upon initial adoption	$ 35,300	$ 35,300
Right of use asset upon initial adoption	$ 29,700	$ 29,700
Operating lease discount rate (in hundredths)	4.50%	4.50%
Operating ground lease expense	$ 600	$ 1,800
Operating ground lease payments	500	1,700
Operating ground lease liabilities, scheduled future minimum payments [Abstract]
October 1 to December 31, 2019	517	517
2020	2,086	2,086
2021	2,127	2,127
2022	2,169	2,169
2023	2,167	2,167
2024	2,123	2,123
Thereafter	83,697	83,697
Operating ground lease liability, total future minimum payments	94,886	94,886
Operating lease liability discount	(59,869)	(59,869)
Operating lease liability	$ 35,017	$ 35,017
Minimum [Member]
Lessor Disclosure [Abstract]
Operating leases, term of leases	3 years	3 years
Maximum [Member]
Lessor Disclosure [Abstract]
Operating leases, term of leases	10 years	10 years