Stock-Based Compensation Management Equity Plans (Details 10) - Management Equity Plan [Member] - USD ($) $ in Thousands		3 Months Ended			6 Months Ended
		Sep. 30, 2016	Jun. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Mar. 31, 2016
Clarion Partners [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Profits interests equity plan participation percentage		15.00%
Deferred Compensation Arrangement with Individual, Compensation Expense			$ 15,200		$ 15,200
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage		20.00%
Deferred Compensation Arrangement with Individual, Fair Value of Shares Issued		$ 18,700
Royce [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Profits interests equity plan participation percentage					16.90%
Stockholders' Equity Attributable to Noncontrolling Interest	[1]	23,186			$ 23,186		$ 22,202
Permal [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Profits interests equity plan participation percentage					15.00%
Aggregate Cost of Awards		$ 9,000			$ 9,000
Deferred Compensation Arrangement with Individual, Compensation Expense				$ 454	3,481	$ 908
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Share-based Liabilities Paid					$ 7,150
ClearBridge Investments [Member]
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Profits interests equity plan participation percentage		15.00%			15.00%
Aggregate Cost of Awards		$ 16,000			$ 16,000
Deferred Compensation Arrangement with Individual, Compensation Expense		$ 817		$ 848	1,635	$ 1,695
Deferred Compensation Arrangement with Individual, Fair Value of Shares Issued					$ 22,160

[1] (2) Related to Royce management equity plan.