Investments in and Advances to Joint Ventures - Service Fees and Income Earned by Company's Unconsolidated Joint Ventures (Detail) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Equity Method Investments And Joint Ventures [Abstract]
Management and other fees	$ 28.6	$ 26.0	$ 24.9
Interest income	33.4	26.0	11.0
Development fees and leasing commissions	$ 7.5	$ 6.8	$ 6.4

Revenue, comprised of base and incentive revenue derived from the management of joint ventures, managing third-party properties, or another entity's operations.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1(d))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration