Debt - Long-Term Debt Maturities (Parenthetical) (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013
Maturities Of Long Term Debt [Line Items]
Debt maturities	$ 78.0
Consolidated Entities [Member]
Maturities Of Long Term Debt [Line Items]
Consolidated investee credit facility included in debt	13.7
Debt maturities	30.0
Consolidated Entities [Member] \| Secured Mortgage Debt [Member]
Maturities Of Long Term Debt [Line Items]
Debt maturities	$ 30.1

Amount of current borrowing capacity under the credit facility considering any current restrictions on the amount that could be borrowed (for example, borrowings may be limited by the amount of current assets), but without considering any amounts currently outstanding under the facility.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

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