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GOODWILL (Narrative) (Details) £ in Millions |  |  |  | 12 Months Ended |
--- | --- | --- | --- | --- | ---
Jun. 12, 2019 USD ($) | Nov. 08, 2018 USD ($) | Oct. 12, 2018 GBP (£) | Oct. 12, 2018 USD ($) | Dec. 31, 2019 USD ($) | Dec. 31, 2018 USD ($) | Dec. 31, 2017 USD ($) | Feb. 21, 2018 USD ($)
Goodwill [Line Items] |  |  |  |  |  |  |  |
Goodwill |  |  |  |  | $ 1,882,020,000 | $ 1,611,535,000 | $ 1,283,457,000 |
Acquisitions of realla |  |  |  |  | 267,804,000 | 329,938,000 |  |
Goodwill, expected tax deductible amount |  |  |  |  | 166,000,000 |  |  |
Goodwill, impairment |  |  |  |  | 0 | $ 0 | $ 0 |
Off Campus Partners |  |  |  |  |  |  |  |
Goodwill [Line Items] |  |  |  |  |  |  |  |
Acquisitions of realla | $ 8,000,000 |  |  |  |  |  |  |
Cozy Services Ltd |  |  |  |  |  |  |  |
Goodwill [Line Items] |  |  |  |  |  |  |  |
Acquisitions of realla |  | $ 52,000,000 |  |  |  |  |  |
Acquisition of cozy |  | $ 53,000,000 |  |  |  |  |  |
Initial amount of cozy goodwill recognized |  |  |  |  | $ (1,000,000) |  |  |
Realla Ltd |  |  |  |  |  |  |  |
Goodwill [Line Items] |  |  |  |  |  |  |  |
Acquisitions of realla |  |  | £ 8 | $ 10,000,000 |  |  |  |
ForRent, Division Of DE Holdings, Inc. |  |  |  |  |  |  |  |
Goodwill [Line Items] |  |  |  |  |  |  |  |
Goodwill |  |  |  |  |  |  |  | $ 266,595,000
Goodwill, expected tax deductible amount |  |  |  |  |  |  |  | $ 8,000,000

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