Business Segment Information (Details) (USD $)	3 Months Ended								12 Months Ended
	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2010	Sep. 30, 2010	Jun. 30, 2010	Mar. 31, 2010	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Services [abstract]
Total revenues									$ 2,752,441,000	$ 2,952,105,000	$ 2,911,290,000
Less: Interest expense									2,550,000	3,548,000	4,411,000
Net revenues	624,978,000	641,529,000	727,994,000	755,390,000	777,561,000	757,567,000	688,343,000	725,086,000	2,749,891,000	2,948,557,000	2,906,879,000
Geographic Information [Abstract]
Net revenues	624,978,000	641,529,000	727,994,000	755,390,000	777,561,000	757,567,000	688,343,000	725,086,000	2,749,891,000	2,948,557,000	2,906,879,000
Long-lived assets	3,477,000,000				3,522,000,000				3,477,000,000	3,522,000,000	3,567,000,000
AllianceBernstein Global High Yield Portfolio [Member]
Concentration Risk [Line Items]
Investment advisory and service fees (in hundredths)									10.00%	7.00%
Percentage of net revenues (in hundredths)									11.00%	8.00%
Customer Concentration Risk [Member] | AXA Advisors LLC [Member]
Major Customers [Abstract]
Open-end mutual fund sales (in hundredths)									1.00%	2.00%	2.00%
Percentage of total revenues from major customer (in hundredths)									1.00%	1.00%	1.00%
Customer Concentration Risk [Member] | HSBC [Member]
Major Customers [Abstract]
Open-end mutual fund sales (in hundredths)									14.00%
Customer Concentration Risk [Member] | UBS AG [Member]
Major Customers [Abstract]
Open-end mutual fund sales (in hundredths)									7.00%
Customer Concentration Risk [Member] | Bank of America Merril Lynch[Member]
Major Customers [Abstract]
Open-end mutual fund sales (in hundredths)									5.00%
Customer Concentration Risk [Member] | AXA and subsidiaries [Member]
Major Customers [Abstract]
Percentage of total revenues from general and separate accounts (in hundredths)									4.00%	5.00%	5.00%
United States [Member]
Services [abstract]
Net revenues									1,725,000,000	1,933,000,000	2,038,000,000
Geographic Information [Abstract]
Net revenues									1,725,000,000	1,933,000,000	2,038,000,000
Long-lived assets	3,403,000,000				3,448,000,000				3,403,000,000	3,448,000,000	3,488,000,000
International [Member]
Services [abstract]
Net revenues									1,025,000,000	1,016,000,000	869,000,000
Geographic Information [Abstract]
Net revenues									1,025,000,000	1,016,000,000	869,000,000
Long-lived assets	74,000,000				74,000,000				74,000,000	74,000,000	79,000,000
Institutions [Member]
Services [abstract]
Total revenues									617,000,000	765,000,000	811,000,000
Retail [Member]
Services [abstract]
Total revenues									1,093,000,000	1,069,000,000	888,000,000
Private Client [Member]
Services [abstract]
Total revenues									652,000,000	651,000,000	590,000,000
Bernstein Research Services [Member]
Services [abstract]
Total revenues									437,000,000	431,000,000	435,000,000
Other Services [Member]
Services [abstract]
Total revenues									$ (47,000,000)	$ 37,000,000	$ 187,000,000