Subsequent Events (Details) $ in Thousands	1 Months Ended		12 Months Ended
	Jan. 31, 2017 USD ($) community unit	Mar. 31, 2015 USD ($)	Dec. 31, 2016 USD ($) unit	Dec. 31, 2015 USD ($) unit	Dec. 31, 2014 USD ($) unit
Subsequent Event [Line Items]
Number of units sold | unit			323	848	594
Sale of apartment community		$ 13,000	$ 80,800	$ 308,800	$ 120,400
Payments to acquire equity method investments		$ 1,300	183,989	$ 127,879	$ 246,006
Encumbrance			$ 2,191,481
Number of units acquired | unit			753
Membership Interest In Palm Valley [Member]
Subsequent Event [Line Items]
Encumbrance			$ 220,000
Subsequent Event [Member] | Jefferson at Hollywood [Member]
Subsequent Event [Line Items]
Number of units sold | unit	270
Sale of apartment community	$ 132,500
Subsequent Event [Member] | Membership Interest In Palm Valley [Member]
Subsequent Event [Line Items]
Equity method investment, ownership percentage	50.00%
Payments to acquire equity method investments	$ 183,000
Number of units acquired | unit	1,098
Number of communities acquired | community	4