Unconsolidated Entities - Summary of Operating Information and Financial Position of Unconsolidated Co-investment Ventures (Parenthetical) (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Equity Method Investments And Joint Ventures [Abstract]
Deferred gain recognized from contribution of property to a venture	$ 635.9	$ 667.3
Additional costs associated with investment in a venture	94.4	94.2
Receivables from unconsolidated co-investment ventures	$ 166.7	$ 103.8

This element represents the aggregate cost of investments accounted for under the equity method of accounting.

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-Name Accounting Standards Codification
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No definition available.

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- Definition

The difference between the carrying value and the sale price of real estate or properties that were intended to be sold or held for capital appreciation or rental income. This element refers to the gain (loss) included in earnings and not to the cash proceeds of the sale. This element is a noncash adjustment to net income when calculating net cash generated by operating activities using the indirect method.

+ References

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- Definition

Receivables to be collected from (obligations owed to) related parties, net as of the balance sheet date where one party can exercise control or significant influence over another party; including affiliates, owners or officers and their immediate families, pension trusts, and so forth.

+ References

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