Acquisitions Martin Currie Acquisition - Purchase Price Allocation (Details) - Martin Currie [Member] £ in Thousands, $ in Thousands	3 Months Ended
	Dec. 31, 2014 GBP (£)	Dec. 31, 2014 USD ($)	Sep. 30, 2015 USD ($)	Oct. 01, 2014 USD ($)
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	£ 125,000	$ 202,577
Business Combination, Contingent Consideration, Liability			$ 71,499	$ 75,211
Business Combination, Consideration Transferred		$ 277,788
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents				29,389
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles				15,234
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment				784
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities				(4,388)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other				(32,433)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Liabilities Noncurrent				(31,537)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net				119,500
Goodwill				158,288
Other Fund Management Contracts [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets				135,321
Trade Names
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Indefinite-Lived Intangible Assets				$ 7,130