Significant Transactions - Summarized Information Regarding Acquisition (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019 USD ($) apartment_home	Dec. 31, 2018 USD ($)
Business Acquisition [Line Items]
Noncontrolling interests in consolidated real estate partnerships	$ 1,500	$ (2,967)
Acquisition costs allocated to land	1,887,424	1,756,525
Acquisition costs allocated to building and improvements	6,848,162	$ 6,552,065
1001 Brickell Bay Drive [Member]
Business Acquisition [Line Items]
Purchase price	156,750
Capitalized transaction costs	2,339
Noncontrolling interests in consolidated real estate partnerships	8,250
Total consideration	167,339
Acquisition costs allocated to land	145,648
Acquisition costs allocated to building and improvements	153,241
Acquisition costs allocated to intangible assets	16,500
Acquisition costs allocated to intangible liabilities	(6,519)
Deferred tax liability assumed	(141,531)
Philadelphia Acquisition
Business Acquisition [Line Items]
Purchase price	65,833
Capitalized transaction costs	892
Total consideration	66,725
Acquisition costs allocated to land	4,929
Acquisition costs allocated to building and improvements	$ 61,271
Number of apartment homes | apartment_home	110
Acquisition costs allocated to furniture and fixtures	$ 525