Earnings Per Share Attributable to Federated Investors, Inc. Shareholders Computation of Basic and Diluted Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Net income attributable to Federated Investors, Inc.		$ 54,925	$ 44,131	$ 153,077	$ 122,197
Less: Total income available to participating unvested restricted shareholders, basic	[1]	(2,035)	(1,691)	(5,987)	(4,837)
Less: Total income available to participating unvested restricted shareholders, diluted	[1]	(2,035)	(1,691)	(5,987)	(4,837)
Total net income attributable to Federated Common Stock, basic	[2]	52,890	42,440	147,090	117,360
Total net income attributable to Federated Common Stock, diluted	[2]	$ 52,890	$ 42,440	$ 147,090	$ 117,360
Basic weighted-average common shares outstanding		98,805	100,449	99,397	100,606
Dilutive potential shares from stock options		1	2	1	1
Diluted weighted-average common shares outstanding		98,806	100,451	99,398	100,607
Net income attributable to Federated Common Stock - Basic and Diluted	[2]	$ 0.54	$ 0.42	$ 1.48	$ 1.17

[1] Income available to participating unvested restricted shareholders includes dividends paid on unvested restricted shares and their proportionate share of undistributed earnings.

[2] Federated Common Stock excludes unvested restricted shares which are deemed participating securities in accordance with the two-class method of computing earnings per share.