Acquisitions QS Investors Acquisition - Purchase Price Allocation (Details) - QS Investors [Domain] - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2014	Sep. 30, 2015	Mar. 31, 2015	May. 30, 2014
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross	$ 11,000
Business Combination, Contingent Consideration, Liability		$ 13,645	$ 13,553	$ 13,370
Business Combination, Consideration Transferred	$ 24,370
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents				441
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Marketable Securities				3,281
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables				2,699
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles				7,060
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment				599
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities, Other				(6,620)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net				7,460
Goodwill				$ 16,910