Commitments and Contingencies Other Commitments - QS Investors (Details) - QS Investors [Domain] - USD ($) $ in Thousands	Sep. 30, 2015	Mar. 31, 2015	May. 30, 2014
Other Commitments [Line Items]
Business Combination, Contingent Consideration, Liability	$ 13,645	$ 13,553	$ 13,370
Contingent payment due on second anniversary of acquisition
Other Commitments [Line Items]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	10,000
Contingent Payment due on fourth anniversary of acquisition
Other Commitments [Line Items]
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High	20,000
Other Current Liabilities [Member]
Other Commitments [Line Items]
Business Combination, Contingent Consideration, Liability	$ 2,684