Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
OTHER NON-OPERATING INCOME (EXPENSE)
Net Income (Loss) Attributable to Noncontrolling Interest	$ 12,617	$ 11,888
Consolidated Legg Mason, Inc.
OPERATING REVENUES
Distribution and service fees	78,906	91,382
Other	1,125	1,008
Revenues	793,842	700,165
OPERATING EXPENSES
Compensation and benefits	413,307	358,625
Distribution and servicing	122,349	124,663
Communications and technology	50,303	52,732
Occupancy	24,408	33,142
Amortization of intangible assets	6,339	5,703
Impairment of Intangible Assets	34,000	0
Impairment of Intangible Assets, Indefinite-lived (Excluding Goodwill)	34,000	0
Contingent consideration fair value adjustments	(16,550)	(18,000)
Other	52,481	69,745
Total Operating Expenses	686,637	626,610
OPERATING INCOME	107,205	73,555
OTHER NON-OPERATING INCOME (EXPENSE)
Interest income	1,468	1,848
Interest expense	(29,266)	(24,565)
Other income (expense), net	11,388	6,585
Total Other Non-Operating Income (Expense)	(15,413)	(12,904)
INCOME BEFORE INCOME TAX PROVISION	91,792	60,651
Income tax provision	28,255	15,311
NET INCOME	63,537	45,340
Net Income (Loss) Attributable to Noncontrolling Interest	12,617	11,888
NET INCOME ATTRIBUTABLE TO LEGG MASON, INC.	$ 50,920	$ 33,452
NET INCOME PER SHARE ATTRIBUTABLE TO LEGG MASON, INC. COMMON SHAREHOLDERS
Basic (in dollars per share)	$ 0.52	$ 0.31
Diluted (in dollars per share)	0.52	0.31
Common Stock, Dividends, Per Share, Declared	$ 0.28	$ 0.22
Consolidated Entity Excluding Consolidated Investment Vehicles Before Eliminations [Member]
OTHER NON-OPERATING INCOME (EXPENSE)
NET INCOME ATTRIBUTABLE TO LEGG MASON, INC.	$ 50,920	$ 33,452
Consolidated Investment Vehicles [Member]
OTHER NON-OPERATING INCOME (EXPENSE)
Other income (expense), net	997	3,228
Separate Accounts [Member] | Consolidated Legg Mason, Inc.
OPERATING REVENUES
Investment Advisory Fees	250,046	226,853
Mutual Funds [Member] | Consolidated Legg Mason, Inc.
OPERATING REVENUES
Investment Advisory Fees	382,228	363,463
Performance Fees [Member] | Consolidated Legg Mason, Inc.
OPERATING REVENUES
Investment Advisory Fees	$ 81,537	$ 17,459