Share-Based Compensation Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
Number of shares authorized under Stock Incentive Plan	27,100,000
Number of shares available for grant under Stock Incentive Plan	1,700,000
Share-based compensation expense	$ 22,508		$ 22,445	$ 22,685
Tax benefit from share-based compensation	8,400		$ 8,400	$ 8,500
Nonvested awards, total compensation cost not yet recognized	$ 74,000
Nonvested awards, total compensation cost not yet recognized, period for recognition	6 years
Restricted stock granted in period	946,570	[1]	943,160	863,137
Restricted stock granted in period, weighted average grant date fair value	$ 27.20	[1]	$ 26.56	$ 31.07
Restricted stock, vested in period, total fair value	$ 23,900		$ 23,900	$ 28,800
Minimum [Member]
Share-based compensation arrangement by share-based payment award, award vesting period	5 years
Maximum [Member]
Share-based compensation arrangement by share-based payment award, award vesting period	10 years
Class B common stock bonus [Member]
Award requisite service period	3 years
Restricted stock granted in period	513,570
Class B common stock key employees [Member]
Award requisite service period	10 years
Restricted stock granted in period	433,000

[1] During 2017, Federated awarded 513,570 shares of restricted Federated Class B common stock in connection with a bonus program in which certain key employees received a portion of their bonus in the form of restricted stock under the Plan. This restricted stock, which was granted on the bonus payment date and issued out of treasury, generally vests over a three-year period. Also during 2017, Federated awarded 433,000 shares of restricted Federated Class B common stock to certain key employees. These restricted stock awards generally vest over a ten-year period.