Equity Investments in Unconsolidated Subsidiaries - Activity Relating to Our Equity Investments in Unconsolidated Subsidiaries (Detail) (USD $) In Thousands, unless otherwise specified			6 Months Ended
Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2013 CTOPI Carried Interest [Member]
Investments in Equity Accounted Investees [Line Items]
Beginning Balance	$ 23,240	$ 13,306	$ 13,306
Incentive income allocation			9,934
Ending Balance	$ 23,240	$ 13,306	$ 23,240

Total investments in (A) an entity in which the entity has significant influence, but does not have control, (B) subsidiaries that are not required to be consolidated and are accounted for using the equity and or cost method, and (C) an entity in which the reporting entity shares control of the entity with another party or group. Includes long-term advances receivable from a party that is affiliated with the reporting entity by means of direct or indirect ownership.

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 210.5-02.12)

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

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