Valuation and Qualifying Account - Allowance for Doubtful Accounts (Details) - Allowance for Doubtful Accounts [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Movement in Valuation Allowances and Reserves
Balance at Beginning of Period	$ 552	$ 725	$ 763
Credited to Costs and Expenses	0	100	0
Deductions	39	273	38
Balance at End of Period	513	552	725
AllianceBernstein L.P. [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Allowance for Doubtful Accounts Receivable, Write-offs	$ 39	$ 273	28
Movement in Valuation Allowances and Reserves
Net reduction to the allowance balance			$ 10