Consolidated Statement of Changes in Equity (Parenthetical) (USD $) In Millions, unless otherwise specified	6 Months Ended
Jun. 30, 2013
Net income (loss) attributable to redeemable noncontrolling interests	$ (1.4)
Payment to redeem noncontrolling member's interest	8.8
Strategic Venture, Commercial Operating Properties
Land assets contributed by a noncontrolling partner	$ 9.4

This element represents the fair value of the noncontrolling interest in the acquiree at the acquisition date.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 805

-SubTopic 20

-Section 50

-Paragraph 1

-Subparagraph (e)(1)

-URI http://asc.fasb.org/extlink&oid=6910749&loc=d3e4845-128472

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 141R

-Paragraph 68

-Subparagraph p(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant