Income Taxes (Tables)

6 Months Ended

Jun. 30, 2019

Income Tax Disclosure [Abstract]

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

	Three Months Ended June 30,								Six Months Ended June 30,
	2019			2018			% Change		2019			2018			% Change
	(in thousands)
Net income attributable to AB Unitholders	$	166,252		$	181,665		(8.5	)%	$	315,366		$	365,861		(13.8	)%
Multiplied by: weighted average equity ownership interest	35.5		%	36.0		%			35.4		%	35.8		%
Equity in net income attributable to AB Unitholders	$	59,023		$	65,388		(9.7	)	$	111,661		$	131,086		(14.8	)
AB qualifying revenues	$	643,019		$	643,009		—		$	1,229,569		$	1,345,927		(8.6	)
Multiplied by: weighted average equity ownership interest for calculating tax	29.4		%	30.2		%			29.5		%	30.2		%
Multiplied by: federal tax	3.5		%	3.5		%			3.5		%	3.5		%
Federal income taxes	6,619			6,794					12,700			14,204
State income taxes	130			137					248			265
Total income taxes	$	6,749		$	6,931		(2.6	)	$	12,948		$	14,469		(10.5	)
Effective tax rate	11.4		%	10.6		%			11.6		%	11.0		%