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Reportable Segments (Details) $ in Thousands | 3 Months Ended | 12 Months Ended |
--- | --- | --- | ---
Dec. 31, 2015 USD ($) | Sep. 30, 2015 USD ($) | Jun. 30, 2015 USD ($) | Mar. 31, 2015 USD ($) | Dec. 31, 2014 USD ($) | Sep. 30, 2014 USD ($) | Jun. 30, 2014 USD ($) | Mar. 31, 2014 USD ($) | Dec. 31, 2015 USD ($) Segments | Dec. 31, 2014 USD ($) | Dec. 31, 2013 USD ($) | Dec. 31, 2012 USD ($)
Reportable Segment (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Number of reportable segments | Segments |  |  |  |  |  |  |  |  | 2 |  |  |
Condition for Community considered to have stabilized occupancy |  |  |  |  |  |  |  |  | 0.9 |  |  |
Number of tenants or related group of tenants that contributed 10% or more of company total revenue |  |  |  |  |  |  |  |  | 0 | 0 | 0 |
Reportable apartment home segment rental income |  |  |  |  |  |  |  |  | $ 894,638 | $ 818,046 | $ 758,926 |
Reportable apartment home segment NOI |  |  |  |  |  |  |  |  | 613,869 | 556,321 | 514,041 |
Joint Venture Managment and Other Fees |  |  |  |  |  |  |  |  | 22,710 | 13,044 | 12,442 |
Reconciling items: |  |  |  |  |  |  |  |  |  |  |  |
Property management |  |  |  |  |  |  |  |  | (23,978) | (22,142) | (20,780) |
Other operating expenses |  |  |  |  |  |  |  |  | (9,708) | (8,271) | (7,136) |
Depreciation and amortization |  |  |  |  |  |  |  |  | (374,598) | (358,154) | (341,490) |
General and administrative |  |  |  |  |  |  |  |  | (59,690) | (47,800) | (42,238) |
Casualty-related (recoveries)/charges, net |  |  |  |  |  |  |  |  | (2,335) | (541) | 12,253 |
Other depreciation and amortization |  |  |  |  |  |  |  |  | (6,679) | (5,775) | (6,741) |
Income/(loss) from unconsolidated entities |  |  |  |  |  |  |  |  | 62,329 | (7,006) | (415) |
Interest Expense |  |  |  |  |  |  |  |  | (121,875) | (130,454) | (126,083) |
Interest and Other Income Including Discontinued Operations |  |  |  |  |  |  |  |  | 1,551 | 11,837 | 4,681 |
Tax benefit/(expense) of taxable REIT subsidiary, net |  |  |  |  |  |  |  |  | 3,886 | 15,136 | 7,299 |
Gain Loss on the Sale of Real Estate, Including Discontinued Operations |  |  |  |  |  |  |  |  | 251,677 | 143,647 | 40,449 |
Redeemable non-controlling interests in OP |  |  |  |  |  |  |  |  | (16,773) | (5,511) | (1,530) |
Noncontrolling Interest in Net Income (Loss) Other Noncontrolling Interests, Nonredeemable |  |  |  |  |  |  |  |  | (3) | 3 | 60 |
Net income/(loss) attributable to Entity |  |  |  |  |  |  |  |  | 340,383 | 154,334 | 44,812 |
Reportable apartment home segment assets: |  |  |  |  |  |  |  |  |  |  |  |
Total segment assets | $ 9,190,276 |  |  |  | $ 8,383,259 |  |  |  | 9,190,276 | 8,383,259 |  |
Accumulated depreciation | (2,646,874) |  |  |  | (2,434,772) |  |  |  | (2,646,874) | (2,434,772) |  |
Total real estate owned, net of accumulated depreciation | 6,543,402 |  |  |  | 5,948,487 |  |  |  | 6,543,402 | 5,948,487 |  |
Reconciling items: |  |  |  |  |  |  |  |  |  |  |  |
Cash and cash equivalents | 6,742 |  |  |  | 15,224 |  |  |  | 6,742 | 15,224 | 30,249 | $ 12,115
Restricted Cash | 20,798 |  |  |  | 22,340 |  |  |  | 20,798 | 22,340 |  |
Deferred financing costs, net |  |  |  |  | 0 |  |  |  |  | 0 |  |
Notes receivable | 16,694 |  |  |  | 14,369 |  |  |  | 16,694 | 14,369 |  |
Investment in and advances to unconsolidated joint ventures, net | 938,906 |  |  |  | 718,226 |  |  |  | 938,906 | 718,226 |  |
Other assets | 137,302 |  |  |  | 110,082 |  |  |  | 137,302 | 110,082 |  |
Total assets | 7,663,844 |  |  |  | 6,828,728 |  |  |  | 7,663,844 | 6,828,728 |  |
Reportable Segments Additional (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Capital expenditures related to segments |  |  |  |  |  |  |  |  | 203,183 | 326,461 | 452,057 |
Same Communities |  |  |  |  |  |  |  |  |  |  |  |
Reportable Segments Additional (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Capital expenditures related to segments |  |  |  |  |  |  |  |  | 72,300 | 52,500 | 43,000 |
Same Communities Western Region |  |  |  |  |  |  |  |  |  |  |  |
Reportable Segment (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Reportable apartment home segment rental income |  |  |  |  |  |  |  |  | 255,346 | 236,175 | 214,324 |
Reportable apartment home segment NOI |  |  |  |  |  |  |  |  | 190,682 | 171,973 | 152,108 |
Reportable apartment home segment assets: |  |  |  |  |  |  |  |  |  |  |  |
Total segment assets | 2,371,615 |  |  |  | 2,336,271 |  |  |  | 2,371,615 | 2,336,271 |  |
Same Communities Mid-Atlantic Region |  |  |  |  |  |  |  |  |  |  |  |
Reportable Segment (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Reportable apartment home segment rental income |  |  |  |  |  |  |  |  | 157,158 | 154,491 | 150,489 |
Reportable apartment home segment NOI |  |  |  |  |  |  |  |  | 108,324 | 107,592 | 105,300 |
Reportable apartment home segment assets: |  |  |  |  |  |  |  |  |  |  |  |
Total segment assets | 1,423,888 |  |  |  | 1,440,561 |  |  |  | 1,423,888 | 1,440,561 |  |
Same Communities Southeastern Region |  |  |  |  |  |  |  |  |  |  |  |
Reportable Segment (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Reportable apartment home segment rental income |  |  |  |  |  |  |  |  | 103,920 | 98,061 | 93,479 |
Reportable apartment home segment NOI |  |  |  |  |  |  |  |  | 69,820 | 65,053 | 61,087 |
Reportable apartment home segment assets: |  |  |  |  |  |  |  |  |  |  |  |
Total segment assets | 730,060 |  |  |  | 727,933 |  |  |  | 730,060 | 727,933 |  |
Same Communities Southwestern Region |  |  |  |  |  |  |  |  |  |  |  |
Reportable Segment (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Reportable apartment home segment rental income |  |  |  |  |  |  |  |  | 57,670 | 54,810 | 52,302 |
Reportable apartment home segment NOI |  |  |  |  |  |  |  |  | 35,767 | 33,725 | 31,925 |
Reportable apartment home segment assets: |  |  |  |  |  |  |  |  |  |  |  |
Total segment assets | 450,305 |  |  |  | 440,587 |  |  |  | 450,305 | 440,587 |  |
Same Communities Northeast Region [Member] |  |  |  |  |  |  |  |  |  |  |  |
Reportable Segment (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Reportable apartment home segment rental income |  |  |  |  |  |  |  |  | 86,048 | 81,500 | 77,299 |
Reportable apartment home segment NOI |  |  |  |  |  |  |  |  | 64,539 | 61,315 | 57,350 |
Reportable apartment home segment assets: |  |  |  |  |  |  |  |  |  |  |  |
Total segment assets | 1,109,354 |  |  |  | 1,076,656 |  |  |  | 1,109,354 | 1,076,656 |  |
Non-Mature communities/Other |  |  |  |  |  |  |  |  |  |  |  |
Reportable Segment (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Reportable apartment home segment rental income |  |  |  |  |  |  |  |  | 211,786 | 180,112 | 167,743 |
Reportable apartment home segment NOI |  |  |  |  |  |  |  |  | 144,737 | 116,663 | 106,271 |
Reportable apartment home segment assets: |  |  |  |  |  |  |  |  |  |  |  |
Total segment assets | 3,105,054 |  |  |  | 2,361,251 |  |  |  | 3,105,054 | 2,361,251 |  |
Reportable Segments Additional (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Capital expenditures related to segments |  |  |  |  |  |  |  |  | 12,900 | 10,900 | 12,800 |
Total Communities [Member] |  |  |  |  |  |  |  |  |  |  |  |
Reportable Segment (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Reportable apartment home segment rental income |  |  |  |  |  |  |  |  | $ 871,928 | 805,149 | $ 755,636 |
United Dominion Reality L.P. |  |  |  |  |  |  |  |  |  |  |  |
Reportable Segment (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Related party management fee percentage |  |  |  |  |  |  |  |  | 2.75% |  |  |
Number of reportable segments | Segments |  |  |  |  |  |  |  |  | 2 |  |  |
Number of tenants or related group of tenants that contributed 10% or more of company total revenue |  |  |  |  |  |  |  |  | 0 |  | 0 |
Reportable apartment home segment rental income |  |  |  |  |  |  |  |  | $ 440,408 | 422,634 | $ 410,842 |
Reportable apartment home segment NOI |  |  |  |  |  |  |  |  | 317,597 | 300,313 | 287,535 |
Reconciling items: |  |  |  |  |  |  |  |  |  |  |  |
Property management |  |  |  |  |  |  |  |  | (12,111) | (11,622) | (11,298) |
Other operating expenses |  |  |  |  |  |  |  |  | (5,923) | (5,172) | (5,728) |
Depreciation and amortization |  |  |  |  |  |  |  |  | (169,784) | (179,176) | (181,302) |
General and administrative |  |  |  |  |  |  |  |  | (27,016) | (28,541) | (24,808) |
Casualty-related (recoveries)/charges, net |  |  |  |  |  |  |  |  | (843) | (541) | 8,083 |
Income/(loss) from unconsolidated entities |  |  |  |  |  |  |  |  | (4,659) | 0 | 0 |
Interest Expense |  |  |  |  |  |  |  |  | (40,321) | (41,717) | (36,058) |
Noncontrolling Interest in Net Income (Loss) Other Noncontrolling Interests, Nonredeemable |  |  |  |  |  |  |  |  | (1,762) | (952) | (4,566) |
Net (loss)/gain on sale of depreciable property |  |  |  |  |  |  |  |  | 158,123 | 63,635 | 41,518 |
Net income/(loss) attributable to Entity | 114,955 | $ 14,617 | $ 47,383 | $ 36,346 | 32,631 | $ 8,637 | $ 24,426 | $ 30,533 | 213,301 | 96,227 | 73,376 |
Reportable apartment home segment assets: |  |  |  |  |  |  |  |  |  |  |  |
Total segment assets | 3,630,905 |  |  |  | 4,238,770 |  |  |  | 3,630,905 | 4,238,770 |  |
Total real estate owned, net of accumulated depreciation | 2,349,647 |  |  |  | 2,835,467 |  |  |  | 2,349,647 | 2,835,467 |  |
Reconciling items: |  |  |  |  |  |  |  |  |  |  |  |
Cash and cash equivalents | 3,103 |  |  |  | 502 |  |  |  | 3,103 | 502 | 1,897 | $ 2,804
Deferred financing costs, net | (2,199) |  |  |  | (4,500) |  |  |  | (2,199) | (4,500) |  |
Investment in and advances to unconsolidated joint ventures, net | 166,186 |  |  |  | 0 |  |  |  | 166,186 | 0 |  |
Other assets | 24,528 |  |  |  | 24,029 |  |  |  | 24,528 | 24,029 |  |
Total assets | 2,554,808 |  |  |  | 2,873,809 |  |  |  | 2,554,808 | 2,873,809 |  |
Reportable Segments Additional (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Capital expenditures related to segments |  |  |  |  |  |  |  |  | 61,196 | 91,682 | 151,002 |
United Dominion Reality L.P. | Same Communities Western Region |  |  |  |  |  |  |  |  |  |  |  |
Reportable Segment (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Reportable apartment home segment rental income |  |  |  |  |  |  |  |  | 174,414 | 160,185 | 150,137 |
Reportable apartment home segment NOI |  |  |  |  |  |  |  |  | 130,509 | 117,130 | 107,866 |
Reportable apartment home segment assets: |  |  |  |  |  |  |  |  |  |  |  |
Total segment assets | 1,461,078 |  |  |  | 1,433,827 |  |  |  | 1,461,078 | 1,433,827 |  |
United Dominion Reality L.P. | Same Communities Mid-Atlantic Region |  |  |  |  |  |  |  |  |  |  |  |
Reportable Segment (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Reportable apartment home segment rental income |  |  |  |  |  |  |  |  | 60,602 | 65,565 | 64,923 |
Reportable apartment home segment NOI |  |  |  |  |  |  |  |  | 40,301 | 44,366 | 44,442 |
Reportable apartment home segment assets: |  |  |  |  |  |  |  |  |  |  |  |
Total segment assets | 410,710 |  |  |  | 686,708 |  |  |  | 410,710 | 686,708 |  |
United Dominion Reality L.P. | Same Communities Southeastern Region |  |  |  |  |  |  |  |  |  |  |  |
Reportable Segment (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Reportable apartment home segment rental income |  |  |  |  |  |  |  |  | 44,981 | 42,568 | 40,730 |
Reportable apartment home segment NOI |  |  |  |  |  |  |  |  | 30,106 | 28,111 | 26,590 |
Reportable apartment home segment assets: |  |  |  |  |  |  |  |  |  |  |  |
Total segment assets | 321,787 |  |  |  | 316,788 |  |  |  | 321,787 | 316,788 |  |
United Dominion Reality L.P. | Same Communities Southwestern Region |  |  |  |  |  |  |  |  |  |  |  |
Reportable Segment (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Reportable apartment home segment rental income |  |  |  |  |  |  |  |  | 20,963 | 26,580 | 25,614 |
Reportable apartment home segment NOI |  |  |  |  |  |  |  |  | 13,176 | 16,821 | 16,057 |
Reportable apartment home segment assets: |  |  |  |  |  |  |  |  |  |  |  |
Total segment assets | 0 |  |  |  | 228,997 |  |  |  | 0 | 228,997 |  |
United Dominion Reality L.P. | Same Communities Northeast Region [Member] |  |  |  |  |  |  |  |  |  |  |  |
Reportable Segment (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Reportable apartment home segment rental income |  |  |  |  |  |  |  |  | 59,444 | 58,788 | 55,850 |
Reportable apartment home segment NOI |  |  |  |  |  |  |  |  | 45,917 | 45,347 | 42,146 |
Reportable apartment home segment assets: |  |  |  |  |  |  |  |  |  |  |  |
Total segment assets | 669,082 |  |  |  | 777,375 |  |  |  | 669,082 | 777,375 |  |
United Dominion Reality L.P. | Non-Mature communities/Other |  |  |  |  |  |  |  |  |  |  |  |
Reportable Segment (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Reportable apartment home segment rental income |  |  |  |  |  |  |  |  | 80,004 | 68,948 | 73,588 |
Reportable apartment home segment NOI |  |  |  |  |  |  |  |  | 57,588 | 48,538 | $ 50,434 |
Reportable apartment home segment assets: |  |  |  |  |  |  |  |  |  |  |  |
Total segment assets | $ 768,248 |  |  |  | $ 795,075 |  |  |  | 768,248 | 795,075 |  |
Reportable Segments Additional (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Capital expenditures related to segments |  |  |  |  |  |  |  |  | $ 5,000 | $ 3,200 |  |
United Dominion Reality L.P. | Minimum |  |  |  |  |  |  |  |  |  |  |  |
Reportable Segment (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Percent occupancy to be considered a community |  |  |  |  |  |  |  |  | 90.00% |  |  |
Community Threshold, Period Above Occupancy Threshold |  |  |  |  |  |  |  |  | 3 months |  |  |
United Dominion Reality L.P. | Taxable REIT Subsidiaries |  |  |  |  |  |  |  |  |  |  |  |
Reportable Segment (Textual) [Abstract] |  |  |  |  |  |  |  |  |  |  |  |
Related party management fee percentage |  |  |  |  |  |  |  |  | 2.75% |  |  |

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- Definition Community Threshold, Percent Occupancy Threshold + References No definition available. + Details
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- Definition Condition for Community considered to have stabilized occupancy. + References No definition available. + Details
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- Definition Rental income less total rental expenses, which includes real estate taxes and insurance, personnel, utilities, repair and maintenance, and administrative and marketing expenses for reportable segments. + References No definition available. + Details
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