Income Taxes (Tables)

9 Months Ended

Sep. 30, 2017

Income Tax Disclosure [Abstract]

Computation of Effective Income Tax Rate and Changes in Components of Income Tax

	Three Months Ended September 30,								Nine Months Ended September 30,
	2017			2016			% Change		2017			2016			% Change
	(in thousands)								(in thousands)
Net income attributable to AB Unitholders	$	140,954		$	158,035		(10.8	)%	$	415,994		$	448,820		(7.3	)%
Multiplied by: weighted average equity ownership interest	34.8		%	35.4		%			35.3		%	35.8		%
Equity in net income attributable to AB Unitholders	$	49,055		$	55,925		(12.3	)	$	146,668		$	160,759		(8.8	)
AB qualifying revenues	$	581,410		$	531,856		9.3		$	1,714,065		$	1,565,294		9.5
Multiplied by: weighted average equity ownership interest for calculating tax	28.3		%	29.8		%			29.2		%	30.1		%
Multiplied by: federal tax	3.5		%	3.5		%			3.5		%	3.5		%
Federal income taxes	5,767			5,549					17,517			16,494
State income taxes	110			118					322			343
Total income taxes	$	5,877		$	5,667		3.7		$	17,839		$	16,837		6.0
Effective tax rate	12.0		%	10.1		%			12.2		%	10.5		%