Amount of transactions with related party during the financial reporting period.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 850

-SubTopic 10

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 850

-SubTopic 10

-Section 50

-Paragraph 3

-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 850

-SubTopic 10

-Section 50

-Paragraph 4

-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39622-107864

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 57

-Paragraph 2

-Subparagraph c

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

Name:	us-gaap_RelatedPartyTransactionAmountsOfTransaction
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Related Party Transactions - Additional Information (Detail) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012 USD ($)	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)	Mar. 31, 2012 USD ($)	Dec. 31, 2012 Affiliated Entity [Member] USD ($)	Dec. 31, 2012 Affiliated Entity [Member] EUR (€)	Dec. 31, 2012 Partnership [Member] USD ($)	Dec. 31, 2012 Partnership [Member] EUR (€)
Related Party Transaction [Line Items]
Maximum percentage of interest on amounts due from affiliates	4.34%
Investment distributed by partners as part of reorganization				$ 127.7
Investments in related European real estate funds					68.9	52.2	54.1	41.0
Payment of aircraft related expenses	$ 8.2	$ 5.7	$ 5.9