Related Party Transactions (Detail)	3 Months Ended
Mar. 31, 2012
Number Of Minority Owned Investment Management Company Affiliates	3

Number of separate investments in which the Company sought to develop relationships with specialty investment management organizations, generally acquiring an equity interest in the business. The Company also invests in certain of the funds and limited partnerships and other legal entities managed by these affiliates and through these funds and partnerships pay management and performance fees to the Company's Investment Manager Affiliates.

No definition available.

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Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration