Intangible Assets and Goodwill (Tables)

12 Months Ended

Mar. 31, 2012

Intangible Assets And Goodwill Disclosure [Abstract]

Components of intangible assets

	2012			2011
Amortizable asset management contracts
Cost	$	206,411		$	208,454
Accumulated amortization	(172,974		)	(155,136		)
Net	33,437			53,318
Indefinite–life intangible assets
Fund management contracts	3,753,629			3,753,657
Trade names	69,800			69,800
	3,823,429			3,823,457
Intangible assets, net	$	3,856,866		$	3,876,775

Estimated amortization expense

2013	$	14,018
2014	11,835
2015	2,920
2016	2,663
2017	2,001
Thereafter	—
Total	$	33,437

Changes in carrying value of goodwill

	Gross Book Value			Accumulated Impairment			Net Book Value
Balance as of March 31, 2010	$	2,477,196		$	(1,161,900	)	$	1,315,296
Impact of excess tax basis amortization	(22,735		)	—			(22,735		)
Other, including changes in foreign exchange rates	19,091			—			19,091
Balance as of March 31, 2011	2,473,552			(1,161,900		)	1,311,652
Impact of excess tax basis amortization	(21,694		)	—			(21,694		)
Other, including changes in foreign exchange rates	(14,913		)	—			(14,913		)
Balance as of March 31, 2012	$	2,436,945		$	(1,161,900	)	$	1,275,045