Fair Value Measurements (Details Textual) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Mar. 31, 2012
Fair Value Measurements (Textual) [Abstract]
Assets measured	$ 1,668,260	$ 1,655,229
Liquidating distributions payable	16,555	31,720
Level 3 [Member]
Fair Value Measurements (Textual) [Abstract]
Assets measured
Liquidating distributions payable

This element represents the aggregate of the assets reported on the balance sheet at period end measured at fair value by the entity. This element is intended to be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

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