Debt	9 Months Ended
Sep. 30, 2018
Debt Disclosure [Abstract]
Debt	Debt As of September 30, 2018 and December 31, 2017, AB had $399.9 million and $491.8 million, respectively, in commercial paper outstanding with weighted average interest rates of approximately 2.2% and 1.6%, respectively. Debt included in the statement of financial condition is presented net of issuance costs of $1.7 million and $1.1 million as of September 30, 2018 and December 31, 2017, respectively. The commercial paper is short term in nature, and as such, recorded value is estimated to approximate fair value (and considered a Level 2 security in the fair value hierarchy). Average daily borrowings of commercial paper during the first nine months of 2018 and the full year 2017 were $372.2 million and $482.2 million, respectively, with weighted average interest rates of approximately 1.9% and 1.2%, respectively. On September 27, 2018, AB amended and restated the existing $1.0 billion committed, unsecured senior revolving credit facility (the “Credit Facility”) with a group of commercial banks and other lenders, reducing the principal amount to $800.0 million and extending the maturity to September 27, 2023. The Credit Facility provides for possible increases in the principal amount by up to an aggregate incremental amount of $200.0 million; any such increase is subject to the consent of the affected lenders. The Credit Facility is available for AB and Sanford C. Bernstein & Co., LLC ("SCB LLC") business purposes, including the support of AB’s commercial paper program. Both AB and SCB LLC can draw directly under the Credit Facility and management may draw on the Credit Facility from time to time. AB has agreed to guarantee the obligations of SCB LLC under the Credit Facility. AB has a $200.0 million, unsecured 364-day senior revolving credit facility (the "Revolver") with a leading international bank and the other lending institutions that may be party thereto, which matures on November 28, 2018. The Revolver is available for AB's and SCB LLC's business purposes, including the provision of additional liquidity to meet funding requirements primarily related to SCB LLC's operations. Both AB and SCB LLC can draw directly under the Revolver and management expects to draw on the Revolver from time to time. AB has agreed to guarantee the obligations of SCB LLC under the Revolver. The Revolver contains affirmative, negative and financial covenants that are identical to those of AB's $800.0 million committed, unsecured senior revolving credit facility. As of September 30, 2018, we had no amounts outstanding under the Revolver. As of December 31, 2017, we had $75.0 million outstanding under the Revolver with an interest rate of 2.4%. Average daily borrowing under the Revolver during the first nine months of 2018 and full year 2017 were $16.7 million and $21.4 million, respectively, with weighted average interest rates of approximately 2.7% and 2.0%, respectively.

Debt

As of September 30, 2018 and December 31, 2017, AB had $399.9 million and $491.8 million, respectively, in commercial paper outstanding with weighted average interest rates of approximately 2.2% and 1.6%, respectively. Debt included in the statement of financial condition is presented net of issuance costs of $1.7 million and $1.1 million as of September 30, 2018 and December 31, 2017, respectively. The commercial paper is short term in nature, and as such, recorded value is estimated to approximate fair value (and considered a Level 2 security in the fair value hierarchy). Average daily borrowings of commercial paper during the first nine months of 2018 and the full year 2017 were $372.2 million and $482.2 million, respectively, with weighted average interest rates of approximately 1.9% and 1.2%, respectively.

On September 27, 2018, AB amended and restated the existing $1.0 billion committed, unsecured senior revolving credit facility (the “Credit Facility”) with a group of commercial banks and other lenders, reducing the principal amount to $800.0 million and extending the maturity to September 27, 2023. The Credit Facility provides for possible increases in the principal amount by up to an aggregate incremental amount of $200.0 million; any such increase is subject to the consent of the affected lenders. The Credit Facility is available for AB and Sanford C. Bernstein & Co., LLC ("SCB LLC") business purposes, including the support of AB’s commercial paper program. Both AB and SCB LLC can draw directly under the Credit Facility and management may draw on the Credit Facility from time to time. AB has agreed to guarantee the obligations of SCB LLC under the Credit Facility.

AB has a $200.0 million, unsecured 364-day senior revolving credit facility (the "Revolver") with a leading international bank and the other lending institutions that may be party thereto, which matures on November 28, 2018. The Revolver is available for AB's and SCB LLC's business purposes, including the provision of additional liquidity to meet funding requirements primarily related to SCB LLC's operations. Both AB and SCB LLC can draw directly under the Revolver and management expects to draw on the Revolver from time to time. AB has agreed to guarantee the obligations of SCB LLC under the Revolver. The Revolver contains affirmative, negative and financial covenants that are identical to those of AB's $800.0 million committed, unsecured senior revolving credit facility. As of September 30, 2018, we had no amounts outstanding under the Revolver. As of December 31, 2017, we had $75.0 million outstanding under the Revolver with an interest rate of 2.4%. Average daily borrowing under the Revolver during the first nine months of 2018 and full year 2017 were $16.7 million and $21.4 million, respectively, with weighted average interest rates of approximately 2.7% and 2.0%, respectively.