Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2019 USD ($) Property ApartmentUnit $ / shares	Dec. 31, 2018 USD ($) $ / shares	Dec. 31, 2017 USD ($) $ / shares	Jan. 01, 2019 USD ($)
Value of furniture and fixtures minimum range	$ 10,000
Value of furniture and fixtures maximum range	$ 35,000
Lease intangibles, average term	6 months
Capitalized costs development and renovation	$ 14,200,000	$ 13,200,000	$ 14,700,000
Lessee, finance lease, description	The Company is a lessor for its residential and retail leases and is a lessee for its corporate headquarters and regional offices and ground leases for land underlying current operating properties or projects under development.  If applicable, lease agreements must be evaluated to determine the accounting treatment as a finance or operating lease in accordance with the new leasing standard.  A lease is classified as a finance lease if it meets any of the following criteria:  (a) Ownership of the underlying asset is transferred to the lessee by the end of the lease term; (b) the lessee has and is reasonably certain to exercise an option to purchase the underlying asset; (c) the lease term is for the major part of the remaining economic life of the underlying asset; (d) the present value of future minimum lease payments is equal to substantially all of the fair value of the underlying asset; and (e) the underlying asset is expected to have no alternative use to the lessor at the end of the lease term due to its specialized nature.
Lessee, finance lease residual value guarantee, description	the present value of future minimum lease payments is equal to substantially all of the fair value of the underlying asset
Common Stock, Par or Stated Value Per Share | $ / shares	$ 0.01	$ 0.01	$ 0.01
Land and depreciable property net	$ 13,700,000,000	$ 14,000,000,000.0
Right-of-use assets	512,774,000			$ 434,201,000
Lease liabilities	$ 331,334,000			$ 278,287,000
Properties | Property	309
Noncontrolling Interests – Partially Owned Properties	$ 1,183,000	$ (2,293,000)
Apartment units | ApartmentUnit	79,962
Partially Owned Properties – Consolidated
Properties | Property	17
Noncontrolling Interests – Partially Owned Properties	$ 1,200,000
Apartment units | ApartmentUnit	3,535
Limited Life Partnership Properties [Member]
Properties | Property	4
Noncontrolling Interests – Partially Owned Properties	$ 10,200,000
Noncontrolling interests settlement value	$ 78,900,000
Minimum [Member] | Retail Commercial Leases [Member]
Retail leases term	5 years
Maximum [Member] | Retail Commercial Leases [Member]
Retail leases term	10 years
Furniture and Fixtures [Member] | Minimum [Member]
Property, plant and equipment, estimated useful lives	5 years
Furniture and Fixtures [Member] | Maximum [Member]
Property, plant and equipment, estimated useful lives	10 years
Building [Member]
Property, plant and equipment, estimated useful lives	30 years
Replacements [Member] | Minimum [Member]
Property, plant and equipment, estimated useful lives	5 years
Replacements [Member] | Maximum [Member]
Property, plant and equipment, estimated useful lives	10 years
Renovations and Improvements Minimum [Member] | Minimum [Member]
Property, plant and equipment, estimated useful lives	5 years
Renovations and Improvements Minimum [Member] | Maximum [Member]
Property, plant and equipment, estimated useful lives	15 years