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Significant Accounting Policies (Details) | 1 Months Ended | 3 Months Ended | 12 Months Ended
--- | --- | --- | ---
Oct. 20, 2015 | Dec. 31, 2015 USD ($) | Sep. 30, 2015 USD ($) | Jun. 30, 2015 USD ($) | Mar. 31, 2015 USD ($) | Dec. 31, 2014 USD ($) $ / shares | Sep. 30, 2014 USD ($) $ / shares | Jun. 30, 2014 USD ($) $ / shares | Mar. 31, 2014 USD ($) $ / shares | Dec. 31, 2015 USD ($) shares | Dec. 31, 2014 USD ($) shares | Dec. 31, 2013 USD ($) shares
Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Deferred Finance Costs, Net |  |  |  |  |  |  | $ 0 |  |  |  |  | $ 0 |
Document Period End Date |  |  |  |  |  |  |  |  |  |  | Dec. 31, 2015 |  |
Significant Accounting Policies (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Development costs excluding direct costs and capitalized interest |  |  |  |  |  |  |  |  |  |  | $ 6,300,000 | 9,000,000 | $ 11,100,000
Interest capitalized during period |  |  |  |  |  |  |  |  |  |  | 16,100,000 | 20,200,000 | 29,400,000
Notes receivable |  |  | $ 16,694,000 |  |  |  | 14,369,000 |  |  |  | 16,694,000 | 14,369,000 |
Number of extension options on loan |  | 2 |  |  |  |  |  |  |  |  |  |  |
Extension period of option on loan |  | 6 months |  |  |  |  |  |  |  |  |  |  |
Note maturity public capital threshold |  |  |  |  |  |  |  |  |  |  | 5,000,000 |  |
Note receivable interest income |  |  |  |  |  |  |  |  |  |  | 1,500,000 | 3,400,000 | 4,100,000
Deferred tax asset |  |  | 11,762,000 |  |  |  | 6,976,000 |  |  |  | 11,762,000 | 6,976,000 | 32,273,000
Net of a valuation allowance |  |  | 81,000 |  |  |  | 0 |  |  |  | 81,000 | 0 | 1,310,000
Valuation Allowance, Deferred Tax Asset, Change in Amount |  |  |  |  |  |  |  |  |  |  | 100,000 |  |
Numerator for earnings per share — basic and diluted: |  |  |  |  |  |  |  |  |  |  |  |  |
Net (loss)/income attributable to common stockholders |  |  | 161,270,000 | $ 12,361,000 | $ 85,924,000 | $ 72,891,000 | $ 64,486,000 | $ 39,618,000 | $ 29,076,000 | $ 17,430,000 | $ 336,661,000 | $ 150,610,000 | $ 41,088,000
Weighted average common shares outstanding | shares |  |  |  |  |  |  |  |  |  |  | 259,873,000 | 252,707,000 | 250,684,000
Net income/(loss) attributable to common stockholders — basic and diluted (in dollars per share) | $ / shares | [1] |  |  |  |  |  | $ 0.25 | $ 0.16 | $ 0.12 | $ 0.07 |  |  |
Advertising expense |  |  |  |  |  |  |  |  |  |  | $ 6,400,000 | $ 6,000,000 | $ 5,700,000
Income Tax Expense (Benefit) |  |  |  |  |  |  |  |  |  |  | (3,886,000) | 25,994,000 | (8,281,000)
Income Tax Examination, Penalties and Interest Accrued |  |  | 0 |  |  |  |  |  |  |  | $ 0 |  |
Minimum Percentage of Carrying Value Of Real Estate Portfolio Held By Company |  |  |  |  |  |  |  |  |  |  | 0.1 |  |
Interest Income, Related Party |  |  |  |  |  |  |  |  |  |  | $ 0.0 | 0.0 | 800,000
(Issuance)/repayment of notes receivable |  |  |  |  |  |  |  |  |  |  | (2,325,000) | 68,664,000 | $ (19,027,000)
Other Assets |  |  | 137,302,000 |  |  |  | $ 110,082,000 |  |  |  | 137,302,000 | 110,082,000 |
Secured debt, net |  |  | 1,376,945,000 |  |  |  | 1,354,321,000 |  |  |  | 1,376,945,000 | 1,354,321,000 |
Unsecured debt, net |  |  | $ 2,193,850,000 |  |  |  | 2,210,978,000 |  |  |  | $ 2,193,850,000 | 2,210,978,000 |
Note due February 2017 |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Notes receivable |  |  |  |  |  |  | 11,869,000 |  |  |  |  | 11,869,000 |
Note Receivable Interest Rate |  |  | 10.00% |  |  |  |  |  |  |  | 10.00% |  |
Aggregate Commitment on Note Receivable |  |  | $ 12,994,000 |  |  |  |  |  |  |  | $ 12,994,000 |  |
Increase (Decrease) in Notes Receivables |  |  |  |  |  |  |  |  |  |  | 1,100,000 |  |
Note maturity public capital threshold |  |  |  |  |  |  |  |  |  |  | 5,000,000 |  |
Other |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Notes receivable |  |  | $ 2,500,000 |  |  |  | 2,500,000 |  |  |  | $ 2,500,000 | 2,500,000 |
Note Receivable Interest Rate |  |  | 8.00% |  |  |  |  |  |  |  | 8.00% |  |
Note due October 2020 [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Notes receivable |  |  | $ 1,200,000 |  |  |  | 0 |  |  |  | $ 1,200,000 | $ 0 |
Note Receivable Interest Rate |  |  | 8.00% |  |  |  |  |  |  |  | 8.00% |  |
Aggregate Commitment on Note Receivable |  |  | $ 2,000,000 |  |  |  |  |  |  |  | $ 2,000,000 |  |
Note maturity public capital threshold |  |  |  |  |  |  |  |  |  |  | $ 10,000,000 |  |
OP Units |  |  |  |  |  |  |  |  |  |  |  |  |
Numerator for earnings per share — basic and diluted: |  |  |  |  |  |  |  |  |  |  |  |  |
Antidilutive securities | shares |  |  |  |  |  |  |  |  |  |  | 12,947,000 | 9,247,000 | 9,337,000
Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |
Numerator for earnings per share — basic and diluted: |  |  |  |  |  |  |  |  |  |  |  |  |
Antidilutive securities | shares |  |  |  |  |  |  |  |  |  |  | 3,032,000 | 3,036,000 | 3,036,000
Stock options and unvested restricted stock |  |  |  |  |  |  |  |  |  |  |  |  |
Numerator for earnings per share — basic and diluted: |  |  |  |  |  |  |  |  |  |  |  |  |
Antidilutive securities | shares |  |  |  |  |  |  |  |  |  |  | 2,051,000 | 1,917,000 | 1,584,000
Minimum | Buildings |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful lives |  |  |  |  |  |  |  |  |  |  | 35 years |  |
Minimum | Building improvements |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful lives |  |  |  |  |  |  |  |  |  |  | 10 years |  |
Minimum | Furniture, fixtures, equipment, and other assets |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful lives |  |  |  |  |  |  |  |  |  |  | 3 years |  |
Maximum | Buildings |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful lives |  |  |  |  |  |  |  |  |  |  | 55 years |  |
Maximum | Building improvements |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful lives |  |  |  |  |  |  |  |  |  |  | 35 years |  |
Maximum | Furniture, fixtures, equipment, and other assets |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful lives |  |  |  |  |  |  |  |  |  |  | 10 years |  |
RedeemableNoncontrollingInterest [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Other Comprehensive (Income) Loss, Net of Tax, Portion Attributable to Noncontrolling Interest |  |  |  |  |  |  |  |  |  |  | $ (308,000) | $ (133,000) | $ 250,000
Continuing Operations [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Numerator for earnings per share — basic and diluted: |  |  |  |  |  |  |  |  |  |  |  |  |
Income Tax Expense (Benefit) |  |  |  |  |  |  |  |  |  |  | (3,886,000) | (15,098,000) | (7,299,000)
Discontinued Operations [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Numerator for earnings per share — basic and diluted: |  |  |  |  |  |  |  |  |  |  |  |  |
Income Tax Expense (Benefit) |  |  |  |  |  |  |  |  |  |  | 0 | 5,000 | (982,000)
United Dominion Reality L P [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Deferred Finance Costs, Net |  |  | 2,199,000 |  |  |  | 4,500,000 |  |  |  | $ 2,199,000 | 4,500,000 |
Document Period End Date |  |  |  |  |  |  |  |  |  |  | Dec. 31, 2015 |  |
Deferred Tax Liabilities, Net |  |  | 0 |  |  |  |  |  |  |  | $ 0 |  |
Significant Accounting Policies (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Development costs excluding direct costs and capitalized interest |  |  |  |  |  |  |  |  |  |  | 700,000 | 2,000,000 | 2,500,000
Interest capitalized during period |  |  |  |  |  |  |  |  |  |  | 200,000 | 2,900,000 | 5,900,000
Numerator for earnings per share — basic and diluted: |  |  |  |  |  |  |  |  |  |  |  |  |
Advertising expense |  |  |  |  |  |  |  |  |  |  | $ 2,400,000 | 2,500,000 | $ 2,500,000
Minimum Percentage of Carrying Value Of Real Estate Portfolio Held By Company |  |  |  |  |  |  |  |  |  |  | 0.10 |  |
Other Assets |  |  | 24,528,000 |  |  |  | 24,029,000 |  |  |  | $ 24,528,000 | 24,029,000 |
Secured debt, net |  |  | 475,964,000 |  |  |  | 927,484,000 |  |  |  | $ 475,964,000 | 927,484,000 |
United Dominion Reality L P [Member] | Minimum | Buildings |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful lives |  |  |  |  |  |  |  |  |  |  | 35 years |  |
United Dominion Reality L P [Member] | Minimum | Building improvements |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful lives |  |  |  |  |  |  |  |  |  |  | 10 years |  |
United Dominion Reality L P [Member] | Minimum | Furniture, fixtures, equipment, and other assets |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful lives |  |  |  |  |  |  |  |  |  |  | 3 years |  |
United Dominion Reality L P [Member] | Maximum | Buildings |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful lives |  |  |  |  |  |  |  |  |  |  | 55 years |  |
United Dominion Reality L P [Member] | Maximum | Building improvements |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful lives |  |  |  |  |  |  |  |  |  |  | 35 years |  |
United Dominion Reality L P [Member] | Maximum | Furniture, fixtures, equipment, and other assets |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Estimated useful lives |  |  |  |  |  |  |  |  |  |  | 10 years |  |
Preferred Stock |  |  |  |  |  |  |  |  |  |  |  |  |
Numerator for earnings per share — basic and diluted: |  |  |  |  |  |  |  |  |  |  |  |  |
Preferred stock, shares redeemed | shares |  |  |  |  |  |  |  |  |  |  | 0 |  |
Reported Value Measurement [Member] | Fair Value, Measurements, Recurring [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Significant Accounting Policies (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |  |
Notes receivable |  |  | 16,694,000 |  |  |  | 14,369,000 |  |  |  | $ 16,694,000 | 14,369,000 |
Secured Debt [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Deferred Finance Costs, Net |  |  | 5,549,000 |  |  |  |  |  |  |  | 5,549,000 |  |
Unsecured Debt [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Deferred Finance Costs, Net |  |  | (12,400,000) |  |  |  |  |  |  |  | (12,400,000) |  |
Reclassification of Deferred Financing Costs [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Deferred Finance Costs, Net |  |  |  |  |  |  | 22,686,000 |  |  |  |  | 22,686,000 |
Other Assets [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Deferred Finance Costs, Net |  |  | (7,900,000) |  |  |  | (4,880,000) |  |  |  | (7,900,000) | (4,880,000) |
Scenario, Previously Reported [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Deferred Finance Costs, Net |  |  |  |  |  |  | (22,686,000) |  |  |  |  | (22,686,000) |
Numerator for earnings per share — basic and diluted: |  |  |  |  |  |  |  |  |  |  |  |  |
Other Assets |  |  |  |  |  |  | 105,202,000 |  |  |  |  | 105,202,000 |
Secured debt, net |  |  |  |  |  |  | 1,361,529,000 |  |  |  |  | 1,361,529,000 |
Unsecured debt, net |  |  |  |  |  |  | 2,221,576,000 |  |  |  |  | 2,221,576,000 |
Scenario, Previously Reported [Member] | United Dominion Reality L P [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Numerator for earnings per share — basic and diluted: |  |  |  |  |  |  |  |  |  |  |  |  |
Secured debt, net |  |  |  |  |  |  | 931,959,000 |  |  |  |  | 931,959,000 |
Secured Debt [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Deferred Finance Costs, Net |  |  |  |  |  |  | 7,208,000 |  |  |  |  | 7,208,000 |
Unsecured Debt [Member] |  |  |  |  |  |  |  |  |  |  |  |  |
Accounting Policies [Line Items] |  |  |  |  |  |  |  |  |  |  |  |  |
Deferred Finance Costs, Net |  |  | $ 12,373,000 |  |  |  | $ 10,598,000 |  |  |  | $ 12,373,000 | $ 10,598,000 |
[1] | .

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