Significant Transactions (Details Textual) $ in Thousands		1 Months Ended	3 Months Ended		6 Months Ended
	Apr. 20, 2020 USD ($)	Jul. 31, 2020 USD ($)	Jun. 30, 2020 USD ($) Property apartment_home Community	Jun. 30, 2019 USD ($) Property apartment_home	Jun. 30, 2020 USD ($) Property apartment_home Community	Jun. 30, 2019 USD ($) Property apartment_home
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Gain on dispositions of real estate			$ 47,238	$ 64,310	$ 47,204	$ 355,783
Subsequent Event [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Non-refundable deposit		$ 5,000
Sales price for a property to be sold		$ 126,000
Wholly And Partially Owned Consolidated Properties [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Number of apartment communities | Property			121		121
Disposal Group, Disposed of by Sale, Not Discontinued Operations [Member] | Wholly And Partially Owned Consolidated Properties [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Number of apartment communities sold | Property			1	1	1	8
Number of apartment homes sold | apartment_home			219	399	219	2,605
Gain on dispositions of real estate			$ 47,200	$ 64,300	$ 47,200	$ 355,800
Disposal Group, Held-for-sale, Not Discontinued Operations
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Number of apartment communities | Community			0		0
Term Loan [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Secured term loan	$ 350,000
Term loan maturity date	Apr. 20, 2021
Term loan option to extend	1 year
Variable interest rate description	currently bears interest at a 30-day LIBOR plus 1.85%, with a 50-basis point LIBOR floor.
Term Loan [Member] | 30-Day LIBOR [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Spread on variable interest rate	1.85%
Term Loan [Member] | LIBOR Floor [Member]
Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]
Spread on variable interest rate	0.50%