Business Combinations Textual (Details) $ / shares in Units, ft² in Thousands		6 Months Ended
	Dec. 01, 2016 USD ($) ft² Communities properties $ / shares shares	Jun. 30, 2017 USD ($) shares	Dec. 31, 2016 shares
Business Acquisition [Line Items]
Embedded Derivative, Fair Value of Embedded Derivative Asset	$ 10,800,000	$ 14,100,000
Business Combinations, Other Consideration	2,000,000
Preferred Stock, Shares Outstanding | shares		867,846
Business Combination, Separately Recognized Transactions [Domain]
Business Acquisition [Line Items]
Business Combination, Merger and Integration Related Expenses		$ 10,400,000
Unsecured Debt [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred, Other	300,000,000
Redeemable Preferred Stock [Member]
Business Acquisition [Line Items]
Mandatorily Redeemable Preferred Stock, Fair Value Disclosure	77.00
Embedded Derivative, Fair Value of Embedded Derivative Asset	$ 14.24
Preferred Stock, Shares Outstanding | shares	868,000
Line of Credit [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred, Other	$ 162,000,000
Parent Company [Member]
Business Acquisition [Line Items]
Preferred Stock, Shares Outstanding | shares		867,846	867,846
Parent Company [Member] | Post [Member] [Domain]
Business Acquisition [Line Items]
Number of Apartment Communities Acquired in Real Estate Property | Communities	61
Number Of Units Acquired In Real Estate Property | Communities	24,138
Number of Commercial Properties Acquired in Real Estate Property | properties	4
Business Acquisition, Cost of Entity Acquired, Purchase Price	$ 4,000,000,000
Share Price | $ / shares	$ 91.41
Stock Issued During Period, Shares, Acquisitions | shares	38,000,000
Equity Method Investments [Member] | Post [Member] [Domain]
Business Acquisition [Line Items]
Number Of Units Acquired In Real Estate Property | Communities	269
Development Portfolio [Member] | Post [Member] [Domain]
Business Acquisition [Line Items]
Number Of Units Acquired In Real Estate Property | Communities	2,262
Commercial [Member] | Parent Company [Member] | Post [Member] [Domain]
Business Acquisition [Line Items]
Square Footage of Real Estate Property | ft²	269
Noncontrolling Interest [Member]
Business Acquisition [Line Items]
Stock Issued During Period, Shares, Acquisitions | shares	80,000