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Acquisitions Martin Currie (Pension Details) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Mar. 31, 2017
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax	$ 121		$ 240
Martin Currie [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	5.40%	5.40%
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)	$ 51	$ 10	26	$ 38
Defined Benefit Plan, Fair Value of Plan Assets	64,071		64,071		$ 59,623
Defined Benefit Plan, Benefit Obligation	101,999		101,999		97,137
Defined Benefit Plan, Funded (Unfunded) Status of Plan	(37,928)		(37,928)		(37,514)
Defined Benefit Plan, Accumulated Other Comprehensive Income (Loss), Gain (Loss), before Tax	(17,619)		(17,619)		$ (16,681)
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 1,919
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	2.70%	2.70%
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	$ 0		$ 0
Fair Value, Inputs, Level 2 [Member] \| Bonds [Member] \| Martin Currie [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Actual Plan Asset Allocations	34.00%		34.00%		35.00%
Defined Benefit Plan, Target Allocation Percentage	0.4
Fair Value, Inputs, Level 1 [Member] \| Cash [Member] \| Martin Currie [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Actual Plan Asset Allocations	1.00%		1.00%
Fair Value, Inputs, Level 1 [Member] \| Equity [Member] \| Martin Currie [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%		65.00%
Defined Benefit Plan, Target Allocation Percentage	0.6