Debt and Preferred Equity Investments (Details 4) (USD $) In Millions, unless otherwise specified	9 Months Ended
Sep. 30, 2014 segment	Dec. 31, 2013
Investments, Debt and Equity Securities [Abstract]
Number of portfolio segments of financial receivables (segment)	1
Additional amount of financing receivables included in other assets	$ 132.6	$ 172.8
Financing Receivable, Recorded Investment, 90 Days Past Due and Still Accruing	$ 0

Recorded investment in financing receivables that are 90 days or more past due and still accruing.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 7

-Subparagraph (d)

-URI http://asc.fasb.org/extlink&oid=28368275&loc=d3e5111-111524

Name:	us-gaap_FinancingReceivableRecordedInvestment90DaysPastDueAndStillAccruing
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant