Commitments and Contingencies - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($) community property Lease	Mar. 31, 2019 USD ($)	Dec. 31, 2019 USD ($)
Lessee, Lease, Description [Line Items]
Number Of Office Leases | Lease	16
Operating lease assets	$ 140,499		$ 103,063
Operating lease obligation	164,829		120,261
Operating Leases, Rent Expense	3,917	$ 3,537
Financing lease asset	21,845		21,898
Financing lease obligation	$ 20,197		$ 20,207
Properties on Land Subject to Land Leases
Lessee, Lease, Description [Line Items]
Number of operating apartment communities owned | community	11
Number of operating apartment communities under construction | community	1
Number of commercial properties owned | property	2
Assets Held under Operating Leases [Member]
Lessee, Lease, Description [Line Items]
Number of operating apartment communities owned | community	10
Assets Held under Finance Leases [Member]
Lessee, Lease, Description [Line Items]
Number of operating apartment communities owned | community	1
Number of Finance Leases for Parking Garages Adjacent to Communities | Lease	2
Number of Finance Leases for Parking Garage Adjacent to Operating Community | Lease	1
Number of Finance Leases for Parking Garage Adjacent to Development Community | Lease	1