Fair Values of Assets and Liabilities Information Regarding Proprietary Fund Products (Details 2) $ in Thousands	Sep. 30, 2015 USD ($)	Mar. 31, 2015 USD ($)
Fair Value, Option, Quantitative Disclosures [Line Items]
Number of Proprietary Fund Products with Seed Capital Investment in Excess of One Million Dollars	47	52
Minimum value of seed investment included in count of funds with corporate investment	$ 1,000
Percentage of Investments In Proprietary Fund Products In Excess of Threshold	90.00%
Proprietary Funds [Member]
Fair Value, Option, Quantitative Disclosures [Line Items]
Investment in Proprietary Fund Products	$ 326,449	$ 392,039

Minimum value of seed investment included in count of funds with corporate seed capital investment.

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- Definition

Number of proprietary fund products with corporate seed investment in the fund in excess of one million dollars

+ References

No definition available.

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- Definition

Percentage of total seed capital investments represented by the number of investments in individual funds over the defined threshold.

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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- Definition

Fair value portion of investment securities, including, but not limited to, marketable securities, derivative financial instruments, and investments accounted for under the equity method.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Trading Securities

-URI http://asc.fasb.org/extlink&oid=6526789

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 35

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=27723805&loc=d3e24584-111560

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 25

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=51813488&loc=d3e22054-111558

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Available-for-Sale Securities

-URI http://asc.fasb.org/extlink&oid=6505594

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Subparagraph a, f, g

-Article 7

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