Acquisitions Martin Currie (Pension Details) (Details) - USD ($) $ in Thousands	3 Months Ended			9 Months Ended			12 Months Ended
	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Mar. 31, 2016
Martin Currie [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Funded Status of Plan	$ (41,568)				$ (41,568)		$ (32,757)
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets					5.40%		5.20%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate					2.80%		3.60%
Defined Benefit Plan, Benefit Obligation	(98,896)				$ (98,896)		$ (90,010)
Defined Benefit Plan, Fair Value of Plan Assets	57,328				57,328		57,253
Defined Benefit Plan, Contributions by Employer		$ 2,152
Defined Benefit Plan, Net Periodic Benefit Cost	28		$ 23		66	$ 70
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), before Tax	$ (21,120)				$ (21,120)		$ (6,821)
Fair Value, Inputs, Level 2 [Member] | Bonds [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Actual Plan Asset Allocations	35.00%				35.00%		40.00%
Defined Benefit Plan, Target Plan Asset Allocations					40.00%
Fair Value, Inputs, Level 1 [Member] | Equity [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Actual Plan Asset Allocations	65.00%				65.00%		60.00%
Defined Benefit Plan, Target Plan Asset Allocations					60.00%
Scenario, Forecast [Member] | Martin Currie [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year				$ 0