Acquisitions Martin Currie Acquisition (Details) - Entity [Domain] £ in Thousands, $ in Thousands	3 Months Ended
	Jun. 30, 2015 USD ($)	Dec. 31, 2014 GBP (£)	Dec. 31, 2014 USD ($)	Jun. 30, 2015 GBP (£)	Jun. 30, 2015 USD ($)	Oct. 01, 2014 USD ($)
Martin Currie [Member]
Business Acquisition [Line Items]
Payments to Acquire Businesses, Gross		£ 125,000	$ 202,577
Business Combination, Contingent Consideration Arrangements, Range of Outcomes, Value, High				£ 325,000	$ 511,445
Business Combination, Contingent Consideration, Liability					73,930	$ 75,211
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability	$ 3,816
Other Current Liabilities [Member]
Business Acquisition [Line Items]
Business Combination, Contingent Consideration, Liability					$ 11,082