Alliancebernstein 10-Q 26 Apr 18 2018 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information	3 Months Ended
	Mar. 31, 2018shares
Document and Entity Information [Abstract]
Entity Registrant Name	ALLIANCEBERNSTEIN L.P.
Entity Central Index Key	1,109,448
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding	269,839,937

Condensed Consolidated Statemen

Condensed Consolidated Statements of Financial Condition - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
ASSETS
Cash and cash equivalents	$ 639,834	$ 671,930
Cash and securities segregated, at fair value (cost: $1,024,491 and $816,350)	1,024,529	816,350
Receivables, net:
Brokers and dealers	281,324	199,690
Brokerage clients	1,733,709	1,647,059
AB funds fees	191,510	212,115
Other fees	123,712	124,164
Investments:
Long-term incentive compensation-related	56,400	66,034
Other	348,981	377,555
Cash and cash equivalents	1,220,555	998,448
Other assets	236,727	211,893
Furniture, equipment and leasehold improvements, net	154,493	157,569
Goodwill	3,066,700	3,066,700
Intangible assets, net	98,748	105,784
Deferred sales commissions, net	23,180	30,126
Total assets	10,561,530	9,295,167
Payables:
Brokers and dealers	350,434	237,861
Securities sold not yet purchased	27,533	29,961
Brokerage clients	2,549,567	2,229,371
AB mutual funds	77,962	82,967
Accounts payable and accrued expenses	451,761	515,660
Accrued compensation and benefits	337,128	270,610
Debt	489,830	565,745
Liabilities	5,507,089	4,630,276
Commitments and contingencies (See Note 13)
Redeemable non-controlling interest	996,966	601,587
Capital:
General Partner	41,218	41,221
Limited partners: 269,839,937 and 268,659,333 units issued and outstanding	4,168,548	4,168,841
Receivables from affiliates	(12,489)	(11,494)
AB Holding Units held for long-term incentive compensation plans	(57,366)	(42,688)
Accumulated other comprehensive loss	(84,066)	(94,140)
Partners’ capital attributable to AB Unitholders	4,055,845	4,061,740
Non-redeemable non-controlling interests in consolidated entities	1,630	1,564
Total capital	4,057,475	4,063,304
Total liabilities, redeemable non-controlling interest and capital	10,561,530	9,295,167
Company-sponsored investment funds
Investments:
Cash and cash equivalents	580,721	326,518
Investments	1,956,470	1,246,283
Other assets	44,492	35,397
Payables:
Liabilities	1,222,874	698,101
Redeemable non-controlling interest	991,602	596,223
Capital:
Non-redeemable non-controlling interests in consolidated entities	$ 710	$ 757

Condensed Consolidated Stateme3

Condensed Consolidated Statements of Financial Condition (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Cash and securities segregated, at cost	$ 1,024,491	$ 816,350
Limited partners, units issued	269,839,937	268,659,333
Limited partners, units outstanding	269,839,937	268,659,333

Condensed Consolidated Stateme4

Condensed Consolidated Statements of Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Revenues:
Investment advisory and services fees	$ 573,598	$ 498,290
Bernstein research services	114,400	112,741
Distribution revenues	108,004	96,554
Dividend and interest income	28,215	14,056
Investment gains (losses)	26,082	25,201
Other revenues	27,028	22,365
Total revenues	877,327	769,207
Less: Interest expense	9,540	4,290
Net revenues	867,787	764,917
Expenses:
Employee compensation and benefits	343,825	321,748
Promotion and servicing:
Distribution-related payments	110,154	94,213
Amortization of deferred sales commissions	6,598	9,079
Trade execution, marketing, T&E and other	54,043	50,368
General and administrative:
General and administrative	121,234	114,221
Real estate credits	(264)	(2)
Contingent payment arrangements	53	177
Interest on borrowings	2,612	1,868
Amortization of intangible assets	6,861	6,933
Total expenses	645,116	598,605
Operating income	222,671	166,312
Income taxes	15,825	10,057
Net income	206,846	156,255
Net income of consolidated entities attributable to non-controlling interests	22,650	16,318
Net income attributable to AB Unitholders	$ 184,196	$ 139,937
Net income per AB Unit:
Basic (in dollars per unit)	$ 0.68	$ 0.52
Diluted (in dollars per unit)	$ 0.68	$ 0.51

Condensed Consolidated Stateme5

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Statement of Comprehensive Income [Abstract]
Net income	$ 206,846	$ 156,255
Other comprehensive income (loss):
Foreign currency translation adjustments, before tax	9,921	9,001
Income tax benefit	0	(134)
Foreign currency translation adjustments, net of tax	9,921	8,867
Unrealized (losses) on investments:
Unrealized (losses) arising during period	0	(16)
Less: reclassification adjustment for (losses) included in net income	0	0
Change in unrealized (losses) on investments	0	(16)
Income tax benefit (expense)	0	(2)
Unrealized (losses) on investments, net of tax	0	(18)
Changes in employee benefit related items:
Amortization of prior service cost	6	6
Recognized actuarial gain	282	259
Changes in employee benefit related items	288	265
Income tax (expense)	(118)	(76)
Employee benefit related items, net of tax	170	189
Other comprehensive income	10,091	9,038
Less: Comprehensive income in consolidated entities attributable to non-controlling interests	22,667	16,394
Comprehensive income attributable to AB Unitholders	$ 194,270	$ 148,899

Condensed Consolidated Stateme6

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income	$ 206,846	$ 156,255
Adjustments to reconcile net income to net cash provided by operating activities:
Amortization of deferred sales commissions	6,598	9,079
Non-cash long-term incentive compensation expense	12,484	7,693
Depreciation and other amortization	17,737	16,282
Unrealized (gains) losses on investments	3,239	(16,397)
Other, net	(2,885)	3,528
Changes in assets and liabilities:
(Increase) in segregated cash and securities	(208,179)	(309,729)
(Increase) in receivables	(140,399)	(206,909)
Decrease (increase) in investments	35,028	20,497
Decrease in deferred sales commissions	348	821
(Increase) decrease in other assets	(68,129)	(32,109)
Increase in payables	425,449	502,976
Increase (decrease) in accounts payable and accrued expenses	5,073	(30,810)
Increase in accrued compensation and benefits	66,012	80,054
Net cash provided by operating activities	164,713	156,956
Cash flows from investing activities:
Purchases of furniture, equipment and leasehold improvements	(5,440)	(6,525)
Net cash used in investing activities	(5,440)	(6,525)
Cash flows from financing activities:
(Repayment) issuance of commercial paper, net	(3,069)	93,581
Repayment of bank loans	(75,000)	0
Increase in overdrafts payable	7,410	50,377
Distributions to General Partner and Unitholders	(247,773)	(198,040)
Capital contributions to non-controlling interests in consolidated entities	(5)	(3,137)
Capital contributions to affiliates	(1,677)	(81)
Additional investments by AB Holding with proceeds from exercise of compensatory options to buy AB Holding Units	4,009	4,468
Purchases of AB Holding Units to fund long-term incentive compensation plan awards, net	(2,128)	(30,833)
Other	21	(412)
Net cash provided by (used in) financing activities	54,573	(88,113)
Effect of exchange rate changes on cash and cash equivalents	8,261	8,049
Net increase in cash and cash equivalents	222,107	70,367
Cash and cash equivalents as of beginning of the period	998,448	994,510
Cash and cash equivalents as of end of the period	1,220,555	1,064,877
Company-sponsored investment funds
Adjustments to reconcile net income to net cash provided by operating activities:
Unrealized (gains) losses on investments	(23,393)	(26,834)
Changes in assets and liabilities:
Decrease (increase) in investments	(686,794)	(153,512)
(Increase) decrease in other assets	515,678	136,071
Cash flows from financing activities:
Subscriptions (redemptions) of investments in consolidated company-sponsored investment funds, net	372,785	$ (4,036)
Cash and cash equivalents as of beginning of the period	326,518
Cash and cash equivalents as of end of the period	$ 580,721

Business Description Organizati

Business Description Organization and Basis of Presentation	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business Description Organization and Basis of Presentation	Business Description Organization and Basis of Presentation Business Description We provide research, diversified investment management and related services globally to a broad range of clients. Our principal services include: • Institutional Services – servicing our institutional clients, including private and public pension plans, foundations and endowments, insurance companies, central banks and governments worldwide, and affiliates such as AXA S.A. ("AXA") and its subsidiaries, by means of separately-managed accounts, sub-advisory relationships, structured products, collective investment trusts, mutual funds, hedge funds and other investment vehicles. • Retail Services – servicing our retail clients, primarily by means of retail mutual funds sponsored by AB or an affiliated company, sub-advisory relationships with mutual funds sponsored by third parties, separately-managed account programs sponsored by financial intermediaries worldwide and other investment vehicles. • Private Wealth Management Services – servicing our private clients, including high-net-worth individuals and families, trusts and estates, charitable foundations, partnerships, private and family corporations, and other entities, by means of separately-managed accounts, hedge funds, mutual funds and other investment vehicles. • Bernstein Research Services – servicing institutional investors, such as pension fund, hedge fund and mutual fund managers, seeking high-quality fundamental research, quantitative services and brokerage-related services in equities and listed options. We also provide distribution, shareholder servicing, transfer agency services and administrative services to the mutual funds we sponsor. Our high-quality, in-depth research is the foundation of our business. Our research disciplines include economic, fundamental equity, fixed income and quantitative research. In addition, we have experts focused on multi-asset strategies, wealth management and alternative investments. We provide a broad range of investment services with expertise in: • Actively-managed equity strategies, with global and regional portfolios across capitalization ranges, concentration ranges and investment strategies, including value, growth and core equities; • Actively-managed traditional and unconstrained fixed income strategies, including taxable and tax-exempt strategies; • Passive management, including index and enhanced index strategies; • Alternative investments, including hedge funds, fund of funds and private equity ( e.g. , direct real estate investing and direct lending); and • Multi-asset solutions and services, including dynamic asset allocation, customized target-date funds and target-risk funds. Our services span various investment disciplines, including market capitalization ( e.g. , large-, mid- and small-cap equities), term ( e.g. , long-, intermediate- and short-duration debt securities), and geographic location ( e.g. , U.S., international, global, emerging markets, regional and local), in major markets around the world. Organization As of March 31, 2018 , AXA, a société anonyme organized under the laws of France and the holding company for the AXA Group, a worldwide leader in financial protection, through certain of its subsidiaries (“AXA and its subsidiaries”) owns approximately 3.9% of the issued and outstanding units representing assignments of beneficial ownership of limited partnership interests in AllianceBernstein Holding L.P. (“AB Holding Units”). AllianceBernstein Corporation (an indirect wholly-owned subsidiary of AXA, “General Partner”) is the general partner of both AllianceBernstein Holding L.P. (“AB Holding”) and AB. AllianceBernstein Corporation owns 100,000 general partnership units in AB Holding and a 1% general partnership interest in AB. As of March 31, 2018 , the ownership structure of AB, including limited partnership units outstanding as well as the general partner's 1% interest, is as follows: AXA and its subsidiaries 63.0 % AB Holding 35.8 Unaffiliated holders 1.2 100.0 % Including both the general partnership and limited partnership interests in AB Holding and AB, AXA and its subsidiaries had an approximate 64.4% economic interest in AB as of March 31, 2018 . Basis of Presentation The interim condensed consolidated financial statements have been prepared in accordance with the instructions to Form 10-Q pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). In the opinion of management, all adjustments, consisting only of normal recurring adjustments, necessary for a fair statement of the interim results, have been made. The preparation of the condensed consolidated financial statements requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the dates of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the interim reporting periods. Actual results could differ from those estimates. The condensed consolidated statement of financial condition as of December 31, 2017 was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America (“GAAP”). Principles of Consolidation The condensed consolidated financial statements include AB and its majority-owned and/or controlled subsidiaries, and the consolidated entities that are considered to be variable interest entities (“VIEs”) and voting interest entities (“VOEs”) in which AB has a controlling financial interest. Non-controlling interests on the condensed consolidated statements of financial condition include the portion of consolidated company-sponsored investment funds in which we do not have direct equity ownership. All significant inter-company transactions and balances among the consolidated entities have been eliminated. Reclassification During 2018, prior period amounts for payments to financial intermediaries for administrative services, sub-accounting services and maintenance of books and records for certain funds previously presented as distribution-related payments are now presented as trade execution, marketing, T&E and other expenses in the condensed consolidated statements of income to conform to the current period's presentation.

Significant Accounting Policies

Significant Accounting Policies	3 Months Ended
	Mar. 31, 2018
Accounting Policies [Abstract]
Significant Accounting Policies	Significant Accounting Policies Recently Adopted Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Codification (“ASC”) 606, Revenue from Contracts with Customers , which outlines a single comprehensive revenue recognition model for all contracts with customers and supersedes most of the existing revenue recognition requirements. We adopted this new standard on January 1, 2018 on a modified retrospective basis for contracts that were not completed as of the date of adoption. The new standard did not change the timing of revenue recognition for our base fees, distribution revenues, shareholder servicing fees and broker-dealer revenues. However, performance-based fees, which, prior to the adoption of ASC 606, were recognized at the end of the applicable measurement period when no risk of reversal remained, and carried-interest distributions received (considered performance-based fees), recorded as deferred revenues until no risk of reversal remained, may in certain instances be recognized earlier under the new standard, if it is probable that significant reversal of performance-based fees recognized will not occur. On January 1, 2018, we recorded a cumulative effect adjustment, net of tax, of a $35.0 million increase to partners’ capital in the condensed consolidated statement of financial condition. This amount represents carried-interest distributions of $77.9 million previously received, net of revenue sharing payments to investment team-members of $42.7 million , with respect to which it is probable that significant reversal will not occur. In January 2016, the FASB issued ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities . The amendment addresses certain aspects of recognition, measurement, presentation and disclosure of financial instruments. We adopted this standard on January 1, 2018. The adoption of this standard did not have a material impact on our financial condition or results of operations. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230) . The amendment is intended to reduce diversity in practice in how certain transactions are classified in the statement of cash flows. We adopted this standard on January 1, 2018. The adoption of this standard did not have a material impact on our financial condition or results of operations. In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash . The new standard requires that the statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Companies are also required to reconcile such total amounts in the balance sheet and disclose the nature of the restrictions. We adopted this standard on January 1, 2018. The adoption of this standard did not have a material impact on our financial condition or results of operations. In March 2017, the FASB issued ASU 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost . The amendment requires that an employer disaggregate the service cost component from the other components of net benefit costs on the income statement. We adopted this standard on January 1, 2018. The adoption of this standard did not have a material impact on our financial condition or results of operations. In May 2017, the FASB issued ASU 2017-09, Compensation - Stock Compensation, Scope of Modification Accounting . The amendment provides clarity and reduces both diversity in practice and cost and complexity when applying the guidance in Topic 718, Compensation - Stock Compensation, to a change to the terms or conditions of a share-based payment award. We adopted this standard on January 1, 2018. The adoption of this standard did not have a material impact on our financial condition or results of operations. Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued ASU 2016-02, Leases . The amendment requires recognition of lease assets and lease liabilities on the statement of financial condition and disclosure of key information about leasing arrangements. Specifically, this guidance requires an operating lease lessee to recognize on the statement of financial condition a liability to make lease payments and a right-of-use asset representing its right to use the underlying asset for the lease term. However, for leases with a term of twelve months or less, a lessee is permitted to make an accounting policy election not to recognize lease assets and lease liabilities. The amendment is effective for fiscal years (and interim periods within those years) beginning after December 15, 2018 and requires lessees to recognize and measure leases at the beginning of the earliest period presented in the financial statements using a modified retrospective approach. Management currently is evaluating the impact that the adoption of this standard will have on our consolidated financial statements. In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment . The guidance removes Step 2 of the goodwill impairment test, which requires a hypothetical purchase price allocation. As a result of the revised guidance, a goodwill impairment will be the amount by which a reporting unit's carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The revised guidance will be applied prospectively, and is effective in 2020. The revised guidance is not expected to have a material impact on our financial condition or results of operations. In February 2018, the FASB issued ASU 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, which permits a company to reclassify the disproportionate income tax effects of the 2017 Tax Cuts and Job Act ("2017 Tax Act") on items within Accumulated Other Comprehensive Income ("AOCI") to retained earnings. The FASB refers to these amounts as "stranded tax effects." The ASU also requires certain new disclosures, some of which are applicable for all companies. The guidance is effective for all companies for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Companies may adopt the new guidance using one of two transition methods: (1) retrospective to each period (or periods) in which the income tax effect of the 2017 Tax Act related to items remaining in AOCI are recognized, or (2) at the beginning of the period of adoption. The adoption of this standard is not expected to have a material impact on our financial condition or results of operations. Revenue Recognition Investment advisory and services fees AB provides asset management services by managing customer assets and seeking to deliver investment returns to investors. Each investment management contract between AB and a customer creates a distinct, separately identifiable performance obligation for each day the customer’s assets are managed as the customer can benefit from each day of service. In accordance with ASC 606, a series of distinct goods and services that are substantially the same and have the same pattern of transfer to the customer are treated as a single performance obligation. Accordingly, we have determined that our investment and advisory services are performed over time and entitle us to variable consideration earned based upon the value of the investors’ assets under management (“AUM”). We calculate AUM using established market-based valuation methods and fair valuation (non-observable market) methods. Market-based valuation methods include: last sale/settle prices from an exchange for actively-traded listed equities, options and futures; evaluated bid prices from recognized pricing vendors for fixed income, asset-backed or mortgage-backed issues; mid prices from recognized pricing vendors and brokers for credit default swaps; and quoted bids or spreads from pricing vendors and brokers for other derivative products. Fair valuation methods include: discounted cash flow models, evaluation of assets versus liabilities or any other methodology that is validated and approved by our Valuation Committee ( see paragraph immediately below for additional information about our Valuation Committee). Fair valuation methods are used only where AUM cannot be valued using market-based valuation methods, such as in the case of private equity or illiquid securities. The Valuation Committee, which consists of senior officers and employees, is responsible for overseeing the pricing and valuation of all investments held in client and AB portfolios. The Valuation Committee has adopted a Statement of Pricing Policies describing principles and policies that apply to pricing and valuing investments held in these portfolios. We also have a Pricing Group, which reports to the Valuation Committee, and is responsible for overseeing the pricing process for all investments. We record as revenue investment advisory and services base fees, which we generally calculate as a percentage of AUM. At month-end, all the components of the transaction price (i.e. the base fee calculation) are no longer variable and the value of the consideration is determined. These fees are not subject to claw back and there is minimal probability that a significant reversal of the revenue recorded will occur. The transaction price for the asset management performance obligation for certain investment advisory contracts, including those associated with hedge funds or other alternative investments, provide for a performance-based fee (including carried interest), in addition to a base advisory fee, which is calculated as either a percentage of absolute investment results or a percentage of investment results in-excess-of a stated benchmark over a specified period-of-time. The performance-based fees are forms of variable consideration and are therefore excluded from the transaction price until it becomes probable that there will not be significant reversal of the cumulative revenue recognized. At each reporting date, we evaluate the constraining factors, discussed below , surrounding the variable consideration to determine the extent to which, if any, that revenues associated with the performance-based fee can be recognized. Constraining factors impacting the amount of variable consideration included in the transaction price include: the contractual claw-back provisions the variable consideration is subject to, the length of time the uncertainty of the consideration is subject to, the number and range of possible consideration amounts, the probability of significant fluctuations in the fund’s market value, the level at which the fund’s value exceeds the contractual threshold required to earn such a fee and the materiality of the amount being evaluated. Prior to the adoption of ASC 606 on January 1, 2018, we recognized performance-based fees at the end of the applicable measurement period when no risk of reversal remained, and carried-interest distributions received as deferred revenues until no risk of reversal remained. Bernstein Research Services Bernstein Research Services revenue consists principally of commissions received for trade execution services and providing equity research services to institutional clients. Brokerage commissions for trade execution services and related expenses are recorded on a trade-date basis when the performance obligations are satisfied. Generally, the transaction price is agreed upon at the point of each trade and based upon the number of shares traded or the value of the consideration traded. Research revenues are recognized when the transaction price is quantified, collectability is assured and that significant reversal of such revenue is not probable. Distribution Revenues Two of our subsidiaries act as distributors and/or placement agents of company-sponsored mutual funds and receive distribution services fees from certain of those funds as partial reimbursement of the distribution expenses they incur. Depending upon the contractual arrangements with the customer and the specific product sold, the variable consideration can be determined in different ways, as discussed below , as we satisfy the performance obligation. Most open-end U.S. funds have adopted a plan under Rule 12b-1 of the Investment Company Act that allows the fund to pay, out of assets of the fund, distribution and service fees for the distribution and sale of its shares (“Rule 12b-1 Fees”). The open-end U.S. funds have such agreements with us, and we have selling and distribution agreements pursuant to which we pay sales commissions to the financial intermediaries that distribute our open-end U.S. funds. These agreements are terminable by either party upon notice (generally 30 days) and do not obligate the financial intermediary to sell any specific amount of fund shares. We record 12b-1 fees monthly based upon a percentage of the net asset value (“NAV”) of the funds. At month-end, the variable consideration of the transaction price is no longer constrained as the NAV can be calculated and the value of consideration is determined. These services are separate and distinct from other asset management services as the customer can benefit from these services independently of other services. We accrue the corresponding 12b-1 fees paid to sub-distributors monthly as the expenses are incurred. We are acting in a principal capacity in these transactions; as such, these revenues and expenses are recorded on a gross basis. We offer back-end load shares in limited instances and charge the investor a contingent deferred sales charge (“CDSC”) if the investment is redeemed within a certain period. The variable consideration for these contracts is contingent upon the timing of the redemption by the investor and the value of the sale proceeds. Due to these constraining factors, we exclude the CDSC fee from the transaction price until the investor redeems the investment. Upon redemption, the cash consideration received for these contractual arrangements are recorded as reductions of unamortized deferred sales commissions. Our Luxembourg subsidiary, the management company for most of our non-U.S. funds, earns a management fee which is accrued daily and paid monthly, at an annual rate, based on the average daily net assets of the fund. With respect to certain share classes, the management fee may also contain a component that is paid to distributors and other financial intermediaries and service providers to cover shareholder servicing and other administrative expenses (also referred to as an All-in-Fee). As we have concluded that asset management is distinct from distribution, we allocate a portion of the investment and advisory fee to distribution revenues for the servicing component based on standalone selling prices. Other Revenues Revenues from contracts with customers include a portion of other revenues, which consists primarily of shareholder servicing fees, as well as mutual fund reimbursements and other brokerage income. We provide shareholder services, which include transfer agency, administrative and recordkeeping services provided to company-sponsored mutual funds. The consideration for these services is based on a percentage of the NAV of the fund or a fixed-fee based on the number of shareholder accounts being serviced. The revenues are recorded at month-end when the constraining factors involved with determining NAV or the number of shareholders’ accounts are resolved. Non-Contractual Revenues Dividend and interest income is accrued as earned. Investment gains and losses on the condensed consolidated statements of income include unrealized gains and losses of trading and private equity investments stated at fair value, equity in earnings of our limited partnership hedge fund investments, and realized gains and losses on investments sold. Contract Assets and Liabilities We use the practical expedient for contracts that have an original duration of one year or less. Accordingly, we do not consider the time value of money and, instead, accrue the incremental costs of obtaining the contract when incurred. As of March 31, 2018, the balances of contract assets and contract liabilities are not considered material and, accordingly, no further disclosures are necessary.

Revenue Recognition

Revenue Recognition	3 Months Ended
	Mar. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenue Recognition	Revenue Recognition See Note 2, Significant Accounting Policies, Revenue Recognition , for descriptions of revenues presented in the table below. The adoption of ASC 606 had no impact on revenue recognition during the first quarter of 2018. Revenues for the three months ended March 31, 2018 and 2017 consisted of the following: Three Months Ended March 31, 2018 2017 (in thousands) Subject to contracts with customers: Investment advisory and services fees Base fees $ 567,338 $ 492,176 Performance-based fees 6,260 6,114 Bernstein research services 114,400 112,741 Distribution revenues All-in-management fees 66,748 54,519 12b-1 fees 22,534 24,789 Other 18,722 17,246 Other revenues Shareholder servicing fees 19,530 17,964 Other 5,628 3,952 821,160 729,501 Not subject to contracts with customers: Dividend and interest income, net of interest expense 18,675 9,766 Investment gains (losses) 26,082 25,201 Other revenues 1,870 449 46,627 35,416 Total net revenues $ 867,787 $ 764,917

Long-term Incentive Compensatio

Long-term Incentive Compensation Plans	3 Months Ended
	Mar. 31, 2018
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Long-term Incentive Compensation Plans	Long-term Incentive Compensation Plans We maintain several unfunded, non-qualified long-term incentive compensation plans, under which we grant annual awards to employees, generally in the fourth quarter, and to members of the Board of Directors of the General Partner, who are not employed by our company or by any of our affiliates (“Eligible Directors”). We fund our restricted AB Holding Unit awards either by purchasing AB Holding Units on the open market or purchasing newly-issued AB Holding Units from AB Holding, and then keeping all of these AB Holding Units in a consolidated rabbi trust until delivering them or retiring them. In accordance with the Amended and Restated Agreement of Limited Partnership of AB (“AB Partnership Agreement”), when AB purchases newly-issued AB Holding Units from AB Holding, AB Holding is required to use the proceeds it receives from AB to purchase the equivalent number of newly-issued AB Units, thus increasing its percentage ownership interest in AB. AB Holding Units held in the consolidated rabbi trust are corporate assets in the name of the trust and are available to the general creditors of AB. During the three months ended March 31, 2018 and 2017 , we purchased 0.1 million and 1.3 million AB Holding Units for $2.3 million and $31.0 million , respectively (on a trade date basis). There were no open-market purchases during the first quarter of 2018. The first quarter 2017 amount reflects open-market purchases of 1.2 million AB Holding Units for $27.8 million , with the remainder relating to purchases of AB Holding Units from employees to allow them to fulfill statutory tax withholding requirements at the time of delivery of long-term incentive compensation awards. Purchases of AB Holding Units reflected on the condensed consolidated statements of cash flows are net of AB Holding Unit purchases by employees as part of a distribution reinvestment election. Each quarter, we consider whether to implement a plan to repurchase AB Holding Units pursuant to Rules 10b5-1 and 10b-18 under the Exchange Act. A plan of this type allows a company to repurchase its shares at times when it otherwise might be prevented from doing so because of self-imposed trading blackout periods or because it possesses material non-public information. Each broker we select has the authority under the terms and limitations specified in the plan to repurchase AB Holding Units on our behalf in accordance with the terms of the plan. Repurchases are subject to regulations promulgated by the SEC as well as certain price, market volume and timing constraints specified in the plan. The plan adopted during the first quarter of 2018 expired at the close of business on April 25, 2018. We may adopt additional plans in the future to engage in open-market purchases of AB Holding Units to help fund anticipated obligations under our incentive compensation award program and for other corporate purposes. During each of the first three months of 2018 and 2017 , we granted to employees and Eligible Directors 1.1 million restricted AB Holding Unit awards. We used AB Holding Units repurchased during the periods and newly-issued AB Holding Units to fund these awards. During the first three months of 2018 and 2017 , AB Holding issued 0.2 million and 0.3 million AB Holding Units, respectively, upon exercise of options to buy AB Holding Units. AB Holding used the proceeds of $4.0 million and $4.5 million , respectively, received from employees as payment in cash for the exercise price to purchase the equivalent number of newly-issued AB Units.

Real Estate Charges

Real Estate Charges	3 Months Ended
	Mar. 31, 2018
Restructuring and Related Activities [Abstract]
Real Estate Charges	Real Estate Charges Since 2010, we have sub-leased over one million square feet of office space. The activity in the liability account relating to our global space consolidation initiatives for the following periods is: Three Months Ended Twelve Months Ended (in thousands) Balance as of beginning of period $ 113,635 $ 112,932 Expense incurred (264 ) 28,507 Deferred rent — 7,083 Payments made (8,981 ) (39,122 ) Interest accretion 1,090 4,235 Balance as of end of period $ 105,480 $ 113,635

Net Income per Unit

Net Income per Unit	3 Months Ended
	Mar. 31, 2018
Earnings Per Unit [Abstract]
Net Income per Unit	Net Income per Unit Basic net income per unit is derived by reducing net income for the 1% general partnership interest and dividing the remaining 99% by the basic weighted average number of limited partnership units outstanding for each period. Diluted net income per unit is derived by reducing net income for the 1% general partnership interest and dividing the remaining 99% by the total of the diluted weighted average number of limited partnership units outstanding for each period. Three Months Ended March 31, 2018 2017 (in thousands, except per unit amounts) Net income attributable to AB Unitholders $ 184,196 $ 139,937 Weighted average limited partnership units outstanding – basic 269,184 268,479 Dilutive effect of compensatory options to buy AB Holding Units 336 534 Weighted average limited partnership units outstanding – diluted 269,520 269,013 Basic net income per AB Unit $ 0.68 $ 0.52 Diluted net income per AB Unit $ 0.68 $ 0.51 For the three months ended March 31, 2018 and 2017 , we excluded 1,225,731 options and 2,437,307 options, respectively, from the diluted net income computation due to their anti-dilutive effect.

Cash Distributions

Cash Distributions	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Cash Distributions	Cash Distributions AB is required to distribute all of its Available Cash Flow, as defined in the AB Partnership Agreement, to its Unitholders and to the General Partner. Available Cash Flow can be summarized as the cash flow received by AB from operations minus such amounts as the General Partner determines, in its sole discretion, should be retained by AB for use in its business, or plus such amounts as the General Partner determines, in its sole discretion, should be released from previously retained cash flow. Typically, Available Cash Flow has been the adjusted diluted net income per unit for the quarter multiplied by the number of general and limited partnership interests at the end of the quarter. In future periods, management anticipates that Available Cash Flow will be based on adjusted diluted net income per unit, unless management determines, with the concurrence of the Board of Directors, that one or more adjustments that are made for adjusted net income should not be made with respect to the Available Cash Flow calculation. On April 26, 2018 , the General Partner declared a distribution of $0.80 per AB Unit, representing a distribution of Available Cash Flow for the three months ended March 31, 2018 . The General Partner, as a result of its 1% general partnership interest, is entitled to receive 1% of each distribution. The distribution is payable on May 17, 2018 to holders of record on May 7, 2018 . The $0.12 difference between diluted net income per AB Unit of $0.68 and the distribution of $0.80 in the first quarter of 2018 primarily resulted from the adoption of revenue recognition standard ASC 606, as a consequence of which $35 million of income was recognized, as previously discussed in Note 2, Significant Accounting Policies .

Cash and Securities Segregated

Cash and Securities Segregated Under Federal Regulations and Other Requirements	3 Months Ended
	Mar. 31, 2018
Brokers and Dealers [Abstract]
Cash and Securities Segregated Under Federal Regulations and Other Requirements	Cash and Securities Segregated Under Federal Regulations and Other Requirements As of March 31, 2018 and December 31, 2017 , $1.0 billion and $0.8 billion , respectively, of U.S. Treasury Bills were segregated in a special reserve bank custody account for the exclusive benefit of our brokerage customers under Rule 15c3-3 of the Exchange Act.

Investments

Investments	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Investments	Investments Investments consist of: March 31, December 31, (in thousands) U.S. Treasury Bills $ 52,685 $ 52,609 Equity securities: Long-term incentive compensation-related 42,022 51,758 Seed capital 137,033 160,672 Other 74,177 81,154 Exchange-traded options 5,395 4,981 Investments in limited partnership hedge funds: Long-term incentive compensation-related 14,378 14,276 Seed capital 24,734 22,923 Private equity (seed capital) 38,011 38,186 Time deposits 5,160 5,138 Other 11,786 11,892 Total investments $ 405,381 $ 443,589 Total investments related to long-term incentive compensation obligations of $56.4 million and $66.0 million as of March 31, 2018 and December 31, 2017 , respectively, consist of company-sponsored mutual funds and hedge funds. For long-term incentive compensation awards granted before 2009, we typically made investments in company-sponsored mutual funds and hedge funds that were notionally elected by plan participants and maintained them (and continue to maintain them) in a consolidated rabbi trust or separate custodial account. The rabbi trust and custodial account enable us to hold such investments separate from our other assets for the purpose of settling our obligations to participants. The investments held in the rabbi trust and custodial account remain available to the general creditors of AB. The underlying investments of the hedge funds in which we invest include long and short positions in equity securities, fixed income securities (including various agency and non-agency asset-based securities), currencies, commodities and derivatives (including various swaps and forward contracts). These investments are valued at quoted market prices or, where quoted market prices are not available, are fair valued based on the pricing policies and procedures of the underlying funds. U.S. Treasury Bills, the majority of which are pledged as collateral with clearing organizations, are held in our investment account. These clearing organizations have the ability by contract or custom to sell or re-pledge this collateral. We allocate seed capital to our investment teams to help develop new products and services for our clients. A portion of our seed capital investments are equity and fixed income products, primarily in the form of separately-managed account portfolios, U.S. mutual funds, Luxembourg funds, Japanese investment trust management funds or Delaware business trusts. We also may allocate seed capital to investments in private equity funds, such as a third-party venture capital fund that invests in communications, consumer, digital media, healthcare and information technology markets. In regard to our seed capital investments, the amounts above reflect those funds in which we are not the primary beneficiary of a VIE or hold a controlling financial interest in a VOE. See Note 14, Consolidated Company-Sponsored Investment Funds , for a description of the seed capital investments that we consolidate. As of March 31, 2018 and December 31, 2017 , our total seed capital investments were $563.3 million and $523.2 million , respectively. Seed capital investments in unconsolidated company-sponsored investment funds are valued using published net asset values or non-published net asset values if they are not listed on an active exchange but have net asset values that are comparable to funds with published net asset values and have no redemption restrictions. In addition, we also have long positions in corporate equities and long exchange-traded options traded through our options desk. The portion of unrealized gains (losses) for the three months ended March 31, 2018 and 2017 related to equity securities held as of March 31, 2018 and 2017 were as follows: Three Months Ended March 31, 2018 2017 (in thousands) Net (losses) gains recognized during the period $ (1,823 ) $ 14,189 Less: net gains recognized during the period on equity securities sold during the period 1,282 1,408 Unrealized (losses) gains recognized during the period on equity securities held $ (3,105 ) $ 12,781

Derivative Instruments

Derivative Instruments	3 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments	Derivative Instruments See Note 14, Consolidated Company-Sponsored Investment Funds , for disclosure of derivative instruments held by our consolidated company-sponsored investment funds. We enter into various futures, forwards, options and swaps to economically hedge certain seed capital investments. Also, we have currency forwards that help us to economically hedge certain balance sheet exposures. In addition, our options desk trades long and short exchange-traded equity options. We do not hold any derivatives designated in a formal hedge relationship under Accounting Standards Codification (“ASC”) 815-10, Derivatives and Hedging . The notional value and fair value as of March 31, 2018 and December 31, 2017 for derivative instruments (excluding derivative instruments relating to our options desk trading activities discussed below ) not designated as hedging instruments were as follows: Fair Value Notional Value Asset Derivatives Liability Derivatives (in thousands) March 31, 2018: Exchange-traded futures $ 178,462 $ 1,517 $ 1,240 Currency forwards 157,448 8,286 8,347 Interest rate swaps 50,403 843 659 Credit default swaps 78,741 1,403 2,410 Total return swaps 135,655 1,516 450 Total derivatives $ 600,709 $ 13,565 $ 13,106 December 31, 2017: Exchange-traded futures $ 163,458 $ 948 $ 2,540 Currency forwards 126,503 8,306 8,058 Interest rate swaps 43,309 951 870 Credit default swaps 74,600 1,247 2,465 Total return swaps 68,106 167 390 Total derivatives $ 475,976 $ 11,619 $ 14,323 As of March 31, 2018 and December 31, 2017 , the derivative assets and liabilities are included in both receivables and payables to brokers and dealers on our condensed consolidated statements of financial condition. The gains and losses for derivative instruments (excluding our options desk trading activities discussed below ) for the three months ended March 31, 2018 and 2017 recognized in investment gains (losses) in the condensed consolidated statements of income were as follows: Three Months Ended March 31, 2018 2017 (in thousands) Exchange-traded futures $ 825 $ (5,532 ) Currency forwards 17 (1,062 ) Interest rate swaps 274 (97 ) Credit default swaps 74 (672 ) Total return swaps 1,177 (2,129 ) Net gains (losses) on derivative instruments $ 2,367 $ (9,492 ) We may be exposed to credit-related losses in the event of nonperformance by counterparties to derivative financial instruments. We minimize our counterparty exposure through a credit review and approval process. In addition, we have executed various collateral arrangements with counterparties to the over-the-counter derivative transactions that require both pledging and accepting collateral in the form of cash. As of March 31, 2018 and December 31, 2017 , we held $2.4 million and $0.5 million , respectively, of cash collateral payable to trade counterparties. This obligation to return cash is reported in payables to brokers and dealers in our condensed consolidated statements of financial condition. Although notional amount is the most commonly used measure of volume in the derivative market, it is not used as a measure of credit risk. Generally, the current credit exposure of our derivative contracts is limited to the net positive estimated fair value of derivative contracts at the reporting date after taking into consideration the existence of netting agreements and any collateral received. A derivative with positive value (a derivative asset) indicates existence of credit risk because the counterparty would owe us if the contract were closed. Alternatively, a derivative contract with negative value (a derivative liability) indicates we would owe money to the counterparty if the contract were closed. Generally, if there is more than one derivative transaction with a single counterparty, a master netting arrangement exists with respect to derivative transactions with that counterparty to provide for aggregate net settlement. Certain of our standardized contracts for over-the-counter derivative transactions (“ISDA Master Agreements”) contain credit risk related contingent provisions pertaining to each counterparty’s credit rating. In some ISDA Master Agreements, if the counterparty’s credit rating, or in some agreements, our assets under management (“AUM”), falls below a specified threshold, either a default or a termination event permitting the counterparty to terminate the ISDA Master Agreement would be triggered. In all agreements that provide for collateralization, various levels of collateralization of net liability positions are applicable, depending on the credit rating of the counterparty. As of March 31, 2018 and December 31, 2017 , we delivered $4.7 million and $8.8 million , respectively, of cash collateral into brokerage accounts. We report this cash collateral in cash and cash equivalents in our condensed consolidated statements of financial condition. As of March 31, 2018 and December 31, 2017 , we held $5.4 million and $5.0 million , respectively, of long exchange-traded equity options, which are included in other investments on our condensed consolidated statements of financial condition. In addition, as of March 31, 2018 and December 31, 2017 , we held $14.0 million and $13.6 million , respectively, of short exchange-traded equity options, which are included in securities sold not yet purchased on our condensed consolidated statements of financial condition. Our options desk provides our clients with equity derivative strategies and execution for exchange-traded options on single stocks, exchange-traded funds and indices. While predominately agency-based, the options desk may commit capital to facilitate a client’s transaction. Our options desk hedges the risks associated with this activity by taking offsetting positions in equities. For the three months ended March 31, 2018 and 2017 , we recognized $4.2 million and $3.7 million , respectively, of losses on equity options activity. These losses are recognized in investment gains (losses) in the condensed consolidated statements of income.

Offsetting Assets and Liabiliti

Offsetting Assets and Liabilities	3 Months Ended
	Mar. 31, 2018
Offsetting [Abstract]
Offsetting Assets and Liabilities	Offsetting Assets and Liabilities See Note 14, Consolidated Company-Sponsored Investment Funds , for disclosure of offsetting assets and liabilities of our consolidated company-sponsored investment funds. Offsetting of assets as of March 31, 2018 and December 31, 2017 was as follows: Gross Amounts of Recognized Assets Gross Amounts Offset in the Statement of Financial Condition Net Amounts of Assets Presented in the Statement of Financial Condition Financial Instruments Cash Collateral Received Net Amount (in thousands) March 31, 2018: Securities borrowed $ 48,302 $ — $ 48,302 $ (46,858 ) $ — $ 1,444 Derivatives $ 13,565 $ — $ 13,565 $ — $ (2,364 ) $ 11,201 Long exchange-traded options $ 5,395 $ — $ 5,395 $ — $ — $ 5,395 December 31, 2017: Securities borrowed $ 85,371 $ — $ 85,371 $ (82,353 ) $ — $ 3,018 Derivatives $ 11,619 $ — $ 11,619 $ — $ (519 ) $ 11,100 Long exchange-traded options $ 4,981 $ — $ 4,981 $ — $ — $ 4,981 Offsetting of liabilities as of March 31, 2018 and December 31, 2017 was as follows: Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Statement of Financial Condition Net Amounts of Liabilities Presented in the Statement of Financial Condition Financial Instruments Cash Collateral Pledged Net Amount (in thousands) March 31, 2018: Securities loaned $ 20,500 $ — $ 20,500 $ (20,500 ) $ — $ — Derivatives $ 13,106 $ — $ 13,106 $ — $ (4,724 ) $ 8,382 Short exchange-traded options $ 13,966 $ — $ 13,966 $ — $ — $ 13,966 December 31, 2017: Securities loaned $ 37,960 $ — $ 37,960 $ (37,922 ) $ — $ 38 Derivatives $ 14,323 $ — $ 14,323 $ — $ (8,794 ) $ 5,529 Short exchange-traded options $ 13,585 $ — $ 13,585 $ — $ — $ 13,585 Cash collateral, whether pledged or received on derivative instruments, is not considered material and, accordingly, is not disclosed by counterparty.

Fair Value

Fair Value	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value	Fair Value See Note 14, Consolidated Company-Sponsored Investment Funds , for disclosure of fair value of our consolidated company-sponsored investment funds. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability ( i.e. , the “exit price”) in an orderly transaction between market participants at the measurement date. The three broad levels of fair value hierarchy are as follows: • Level 1 – Quoted prices in active markets are available for identical assets or liabilities as of the reported date. • Level 2 – Quoted prices in markets that are not active or other pricing inputs that are either directly or indirectly observable as of the reported date. • Level 3 – Prices or valuation techniques that are both significant to the fair value measurement and unobservable as of the reported date. These financial instruments do not have two-way markets and are measured using management’s best estimate of fair value, where the inputs into the determination of fair value require significant management judgment or estimation. Assets and Liabilities Measured at Fair Value on a Recurring Basis Valuation of our financial instruments by pricing observability levels as of March 31, 2018 and December 31, 2017 was as follows (in thousands): Level 1 Level 2 Level 3 NAV Expedient (1) Other Total March 31, 2018: Money markets $ 48,942 $ — $ — $ — $ — $ 48,942 Securities segregated (U.S. Treasury Bills) — 1,024,529 — — — 1,024,529 Derivatives 1,517 12,048 — — — 13,565 Investments U.S. Treasury Bills — 52,685 — — — 52,685 Equity securities 237,169 15,533 117 413 — 253,232 Long exchange-traded options 5,395 — — — — 5,395 Limited partnership hedge funds (2) — — — — 39,112 39,112 Private equity — — 954 37,057 — 38,011 Time deposits (3) — — — — 5,160 5,160 Other investments — — — — 11,786 11,786 Total investments 242,564 68,218 1,071 37,470 56,058 405,381 Total assets measured at fair value $ 293,023 $ 1,104,795 $ 1,071 $ 37,470 $ 56,058 $ 1,492,417 Securities sold not yet purchased Short equities – corporate $ 13,567 $ — $ — $ — $ — $ 13,567 Short exchange-traded options 13,966 — — — — 13,966 Derivatives 1,240 11,866 — — — 13,106 Contingent payment arrangements — — 10,908 — — 10,908 Total liabilities measured at fair value $ 28,773 $ 11,866 $ 10,908 $ — $ — $ 51,547 December 31, 2017: Money markets $ 62,071 $ — $ — $ — $ — $ 62,071 Securities segregated (U.S. Treasury Bills) — 816,350 — — — 816,350 Derivatives 948 10,671 — — — 11,619 Investments U.S. Treasury Bills — 52,609 — — — 52,609 Equity securities 276,755 16,618 117 94 — 293,584 Long exchange-traded options 4,981 — — — — 4,981 Limited partnership hedge funds (2) — — — — 37,199 37,199 Private equity — — 954 37,232 — 38,186 Time deposits (3) — — — — 5,138 5,138 Other investments — — — — 11,892 11,892 Total investments 281,736 69,227 1,071 37,326 54,229 443,589 Total assets measured at fair value $ 344,755 $ 896,248 $ 1,071 $ 37,326 $ 54,229 $ 1,333,629 Securities sold not yet purchased Short equities – corporate $ 16,376 $ — $ — $ — $ — $ 16,376 Short exchange-traded options 13,585 — — — — 13,585 Derivatives 2,540 11,783 — — — 14,323 Contingent payment arrangements — — 10,855 — — 10,855 Total liabilities measured at fair value $ 32,501 $ 11,783 $ 10,855 $ — $ — $ 55,139 (1) Investments measured at fair value using NAV (or its equivalent) as a practical expedient. (2) Investments in equity method investees that are not measured at fair value in accordance with GAAP. (3) Investments carried at amortized cost that are not measured at fair value in accordance with GAAP. One of our private equity investments (measured at fair value using NAV as a practical expedient) is a venture capital fund with a fair value of $37.1 million and no unfunded commitment as of March 31, 2018 . This partnership invests in communications, consumer, digital media, healthcare and information technology markets. The fair value of this investment has been estimated using the capital account balances provided by the partnership. The interest in this partnership cannot be redeemed without specific approval by the general partner. Other investments include (i) an investment in a start-up company that does not have a readily available fair value ( $4.6 million as March 31, 2018 and December 31, 2017 ), (ii) an investment in an equity method investee that is not measured at fair value in accordance with GAAP ( $4.0 million as March 31, 2018 and $4.1 million as of December 31, 2017 ), and (iii) broker dealer exchange memberships ( $3.2 million as March 31, 2018 and December 31, 2017 ). We provide below a description of the fair value methodologies used for instruments measured at fair value, as well as the general classification of such instruments pursuant to the valuation hierarchy: • Money markets : We invest excess cash in various money market funds that are valued based on quoted prices in active markets; these are included in Level 1 of the valuation hierarchy. • Treasury Bills : We hold U.S. Treasury Bills, which are primarily segregated in a special reserve bank custody account as required by Rule 15c3-3 of the Exchange Act. These securities are valued based on quoted yields in secondary markets and are included in Level 2 of the valuation hierarchy. • Equity securities : Our equity securities consist principally of company-sponsored mutual funds with NAVs and various separately-managed portfolios consisting primarily of equity and fixed income mutual funds with quoted prices in active markets, which are included in Level 1 of the valuation hierarchy. In addition, some securities are valued based on observable inputs from recognized pricing vendors, which are included in Level 2 of the valuation hierarchy. • Derivatives : We hold exchange-traded futures with counterparties that are included in Level 1 of the valuation hierarchy. In addition, we also hold currency forward contracts, interest rate swaps, credit default swaps, option swaps and total return swaps with counterparties that are valued based on observable inputs from recognized pricing vendors, which are included in Level 2 of the valuation hierarchy. • Options : We hold long exchange-traded options that are included in Level 1 of the valuation hierarchy. • Private equity : Generally, the valuation of private equity investments requires significant management judgment due to the absence of quoted market prices, inherent lack of liquidity and the long-term nature of such investments. Private equity investments are valued initially at cost. The carrying values of private equity investments are adjusted either up or down from cost to reflect expected exit values as evidenced by financing and sale transactions with third parties, or when determination of a valuation adjustment is confirmed through ongoing review in accordance with our valuation policies and procedures. A variety of factors are reviewed and monitored to assess positive and negative changes in valuation, including current operating performance and future expectations of investee companies, industry valuations of comparable public companies, changes in market outlooks, and the third party financing environment over time. In determining valuation adjustments resulting from the investment review process, particular emphasis is placed on current company performance and market conditions. For these reasons, which make the fair value of private equity investments unobservable, equity investments are included in Level 3 of the valuation hierarchy. If private equity investments become publicly traded, they are included in Level 1 of the valuation hierarchy; provided, however, if they contain trading restrictions, publicly-traded equity investments are included in Level 2 of the valuation hierarchy until the trading restrictions expire. • Securities sold not yet purchased : Securities sold not yet purchased, primarily reflecting short positions in equities and exchange-traded options, are included in Level 1 of the valuation hierarchy. • Contingent payment arrangements : Contingent payment arrangements relate to contingent payment liabilities associated with various acquisitions. At each reporting date, we estimate the fair values of the contingent consideration expected to be paid based upon probability-weighted AUM and revenue projections, using unobservable market data inputs, which are included in Level 3 of the valuation hierarchy. During the three months ended March 31, 2018 , there were no transfers between Level 1 and Level 2 securities. The change in carrying value associated with Level 3 financial instruments carried at fair value, classified as private equity and trading equity securities, is as follows: Three Months Ended March 31, 2018 2017 (in thousands) Balance as of beginning of period $ 1,071 $ 5,023 Purchases — — Sales — — Realized gains (losses), net — — Unrealized gains (losses), net — 3 Balance as of end of period $ 1,071 $ 5,026 Transfers into and out of all levels of the fair value hierarchy are reflected at end-of-period fair values. Realized and unrealized gains and losses on Level 3 financial instruments are recorded in investment gains and losses in the condensed consolidated statements of income. As of March 31, 2018 and December 31, 2017 , we have an investment in a private equity fund focused exclusively on the energy sector (fair value of $1.0 million as of both periods) that is classified as Level 3.This investment's valuation is based on a market approach, considering recent transactions in the fund and the industry. We acquired Ramius Alternative Solutions LLC in 2016, CPH Capital Fondsmaeglerselskab A/S in 2014 and SunAmerica's alternative investment group in 2010, all of which included contingent consideration arrangements as part of the purchase price. The change in carrying value associated with Level 3 financial instruments carried at fair value, classified as contingent payment arrangements, is as follows: Three Months Ended March 31, 2018 2017 (in thousands) Balance as of beginning of period $ 10,855 $ 17,589 Accretion 53 178 Payments — (590 ) Balance as of end of period $ 10,908 $ 17,177 During the third quarter of 2017 , we made the final contingent consideration payment relating to our 2014 acquisition and recorded a change in estimate and wrote off the remaining contingent consideration payable relating to our 2010 acquisition. As of March 31, 2018 and December 31, 2017 , one acquisition-related contingent liability of $10.9 million for both periods remains relating to our 2016 acquisition, which was valued using a revenue growth rate of 31% and a discount rate ranging from 1.4% to 2.3% . Assets and Liabilities Measured at Fair Value on a Nonrecurring Basis We did not have any material assets or liabilities that were measured at fair value for impairment on a nonrecurring basis during the three months ended March 31, 2018 or during the year ended December 31, 2017 .

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Proceedings With respect to all significant litigation matters, we consider the likelihood of a negative outcome. If we determine the likelihood of a negative outcome is probable and the amount of the loss can be reasonably estimated, we record an estimated loss for the expected outcome of the litigation. If the likelihood of a negative outcome is reasonably possible and we are able to determine an estimate of the possible loss or range of loss in excess of amounts already accrued, if any, we disclose that fact together with the estimate of the possible loss or range of loss. However, it is often difficult to predict the outcome or estimate a possible loss or range of loss because litigation is subject to inherent uncertainties, particularly when plaintiffs allege substantial or indeterminate damages. Such is also the case when the litigation is in its early stages or when the litigation is highly complex or broad in scope. In these cases, we disclose that we are unable to predict the outcome or estimate a possible loss or range of loss. AB may be involved in various matters, including regulatory inquiries, administrative proceedings and litigation, some of which may allege significant damages. It is reasonably possible that we could incur losses pertaining to these matters, but currently we cannot estimate any such additional losses. Management, after consultation with legal counsel, currently believes that the outcome of any individual matter that is pending or threatened, or all of them combined, will not have a material adverse effect on our results of operations, financial condition or liquidity. However, any inquiry, proceeding or litigation has an element of uncertainty; management cannot determine whether further developments relating to any individual matter that is pending or threatened, or all of them combined, will have a material adverse effect on our results of operation, financial condition or liquidity in any future reporting period.

Consolidated Company-Sponsored

Consolidated Company-Sponsored Investment Funds	3 Months Ended
	Mar. 31, 2018
Consolidated Company-Sponsored Investment Funds [Abstract]
Consolidated Company-Sponsored Investment Funds	Consolidated Company-Sponsored Investment Funds We regularly provide seed capital to new company-sponsored investment funds. As such, we may consolidate or de-consolidate a variety of company-sponsored investment funds each quarter. Due to the similarity of risks related to our involvement with each company-sponsored investment fund, disclosures required under the VIE model are aggregated, such as disclosures regarding the carrying amount and classification of assets. We are not required to provide financial support to company-sponsored investment funds and only the assets of such funds are available to settle each fund's own liabilities. Our exposure to loss in regard to consolidated company-sponsored investment funds is limited to our investment in, and our management fee earned from, such funds. Equity and debt holders of such funds have no recourse to AB’s assets or to the general credit of AB. The balances of consolidated VIEs and VOEs included in our condensed consolidated statements of financial condition were as follows: March 31, 2018 December 31, 2017 (in thousands) VIEs VOEs Total VIEs VOEs Total Cash and cash equivalents $ 580,239 $ 482 $ 580,721 $ 326,158 $ 360 $ 326,518 Investments 1,826,576 129,894 1,956,470 1,189,835 56,448 1,246,283 Other assets 40,242 4,250 44,492 33,931 1,466 35,397 Total assets $ 2,447,057 $ 134,626 $ 2,581,683 $ 1,549,924 $ 58,274 $ 1,608,198 Liabilities $ 1,218,612 $ 4,262 $ 1,222,874 $ 695,997 $ 2,104 $ 698,101 Redeemable non-controlling interest 981,961 9,641 991,602 596,241 (18 ) 596,223 Partners' capital attributable to AB Unitholders 245,774 120,723 366,497 256,929 56,188 313,117 Non-redeemable non-controlling interests in consolidated entities 710 — 710 757 — 757 Total liabilities, redeemable non-controlling interest and partners' capital $ 2,447,057 $ 134,626 $ 2,581,683 $ 1,549,924 $ 58,274 $ 1,608,198 Fair Value Cash and cash equivalents include cash on hand, demand deposits, overnight commercial paper and highly liquid investments with original maturities of three months or less. Due to the short-term nature of these instruments, the recorded value has been determined to approximate fair value. Valuation of consolidated company-sponsored investment funds' financial instruments by pricing observability levels as of March 31, 2018 and December 31, 2017 was as follows (in thousands): Level 1 Level 2 Level 3 NAV Expedient Total March 31, 2018: Investments - VIEs $ 1,612,691 $ 208,118 $ 5,767 $ — $ 1,826,576 Investments - VOEs 77,172 52,588 134 — 129,894 Derivatives - VIEs 769 30,237 — — 31,006 Derivatives - VOEs 43 595 — — 638 Total assets measured at fair value $ 1,690,675 $ 291,538 $ 5,901 $ — $ 1,988,114 Short equities - VIEs $ 1,188,624 $ — $ — $ — $ 1,188,624 Derivatives - VIEs 1,027 17,373 — — 18,400 Derivatives - VOEs 89 587 — — 676 Total liabilities measured at fair value $ 1,189,740 $ 17,960 $ — $ — $ 1,207,700 December 31, 2017: Investments - VIEs $ 1,053,824 $ 133,796 $ 2,205 $ 10 $ 1,189,835 Investments - VOEs 5,491 50,898 59 — 56,448 Derivatives - VIEs 252 30,384 — — 30,636 Derivatives - VOEs 49 251 — — 300 Total assets measured at fair value $ 1,059,616 $ 215,329 $ 2,264 $ 10 $ 1,277,219 Short equities - VIEs $ 669,258 $ — $ — $ — $ 669,258 Derivatives - VIEs 421 21,820 — — 22,241 Derivatives - VOEs 12 619 — — 631 Total liabilities measured at fair value $ 669,691 $ 22,439 $ — $ — $ 692,130 See Note 12 for a description of the fair value methodologies used for instruments measured at fair value, as well as the general classification of such instruments pursuant to the valuation hierarchy. The change in carrying value associated with Level 3 financial instruments carried at fair value within consolidated company-sponsored investment funds was as follows: Three Months Ended March 31, 2018 2017 (in thousands) Balance as of beginning of period $ 2,264 $ 5,741 Transfers (out) in (13 ) 749 Purchases 4,034 4,577 Sales (333 ) (1,073 ) Realized gains (losses), net 5 (12 ) Unrealized (losses) gains, net (58 ) 271 Accrued discounts 2 20 Balance as of end of period $ 5,901 $ 10,273 The Level 3 securities primarily consist of corporate bonds that are vendor priced with no ratings available, bank loans, non-agency collateralized mortgage obligations and asset-backed securities. Transfers into and out of all levels of the fair value hierarchy are reflected at end-of-period fair values. Realized and unrealized gains and losses on Level 3 financial instruments are recorded in investment gains and losses in the condensed consolidated statements of income. Derivative Instruments As of March 31, 2018 and December 31, 2017 , the VIEs held $12.6 million and $8.4 million (net), respectively, of futures, forwards and swaps within their portfolios. For the three months ended March 31, 2018 and 2017 , we recognized $14.9 million of losses and $7.2 million of gains, respectively, on these derivatives. These gains and losses are recognized in investment gains (losses) in the condensed consolidated statements of income. As of March 31, 2018 and December 31, 2017 , the VIEs held $2.3 million and $0.2 million , respectively, of cash collateral payable to trade counterparties. This obligation to return cash is reported in the liabilities of consolidated company-sponsored investment funds in our condensed consolidated statements of financial condition. As of March 31, 2018 and December 31, 2017 , the VIEs delivered $1.4 million and $2.9 million , respectively, of cash collateral into brokerage accounts. The VIEs report this cash collateral in the consolidated company-sponsored investment funds cash and cash equivalents in our condensed consolidated statements of financial condition. As of March 31, 2018 and December 31, 2017 , the VOE held $38 thousand and $0.3 million (net), respectively of futures, forwards, options and swaps within their portfolios. For the three months ended March 31, 2018 and 2017 , we recognized $0.5 million and $0.4 million of losses, respectively, on these derivatives. These gains and losses are recognized in investment gains (losses) in the condensed consolidated statements of income. As of March 31, 2018 , the VOEs held $47 thousand of cash collateral payable to trade counterparties. This obligation to return cash is reported in the liabilities of consolidated company-sponsored investment funds in our condensed consolidated statement of financial condition. As of March 31, 2018 and December 31, 2017 , the VOEs held $0.3 million and $0.2 million of cash collateral into brokerage accounts. The VOEs report this cash collateral in the consolidated company-sponsored investment funds cash and cash equivalents in our condensed consolidated statements of financial condition. Offsetting Assets and Liabilities Offsetting of derivative assets of consolidated company-sponsored investment funds as of March 31, 2018 and December 31, 2017 was as follows: Gross Amounts of Recognized Assets Gross Amounts Offset in the Statement of Financial Condition Net Amounts of Assets Presented in the Statement of Financial Condition Financial Instruments Cash Collateral Received Net Amount (in thousands) March 31, 2018: Derivatives - VIEs $ 31,006 $ — $ 31,006 $ — $ (2,271 ) $ 28,735 Derivatives - VOEs $ 638 $ — $ 638 $ — $ (47 ) $ 591 December 31, 2017: Derivatives - VIEs $ 30,636 $ — $ 30,636 $ — $ (194 ) $ 30,442 Derivatives - VOEs $ 300 $ — $ 300 $ — $ (37 ) $ 263 Offsetting of derivative liabilities of consolidated company-sponsored investment funds as of March 31, 2018 and December 31, 2017 was as follows: Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Statement of Financial Condition Net Amounts of Liabilities Presented in the Statement of Financial Condition Financial Instruments Cash Collateral Pledged Net Amount (in thousands) March 31, 2018: Derivatives - VIEs $ 18,400 $ — $ 18,400 $ — $ (1,372 ) $ 17,028 Derivatives - VOEs $ 676 $ — $ 676 $ — $ (253 ) $ 423 December 31, 2017: Derivatives - VIEs $ 22,241 $ — $ 22,241 $ — $ (2,884 ) $ 19,357 Derivatives - VOEs $ 631 $ — $ 631 $ — $ (228 ) $ 403 Cash collateral, whether pledged or received on derivative instruments, is not considered material and, accordingly, is not disclosed by counterparty. Non-Consolidated VIEs As of March 31, 2018 , the net assets of company-sponsored investment products that are non-consolidated VIEs are approximately $83.9 billion , and our maximum risk of loss is our investment of $8.0 million in these VIEs and advisory fee receivables from these VIEs, which are not material.

Units Outstanding

Units Outstanding	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Units Outstanding	Units Outstanding Changes in AB Units outstanding during the three -month period ended March 31, 2018 were as follows: Outstanding as of December 31, 2017 268,659,333 Options exercised 235,105 Units issued 949,185 Units retired (1) (3,686 ) Balance as of March 31, 2018 269,839,937 (1) Includes 1,150 AB Units purchased in private transactions and retired during the first three months of 2018 .

Debt

Debt	3 Months Ended
	Mar. 31, 2018
Debt Disclosure [Abstract]
Debt	Debt As of March 31, 2018 and December 31, 2017 , AB had $489.8 million and $491.8 million , respectively, in commercial paper outstanding with weighted average interest rates of approximately 2.1% and 1.6% , 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 three months of 2018 and the full year 2017 were $480.5 million and $482.2 million , respectively, with weighted average interest rates of approximately 1.7% and 1.2% , respectively. 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 the Credit Facility. As of March 31, 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 three months of 2018 and full year 2017 were $21.9 million and $21.4 million , respectively, with weighted average interest rates of approximately 2.4% and 2.0% , respectively.

Changes in Capital

Changes in Capital	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Changes in Capital	Changes in Capital Changes in capital during the three -month period ended March 31, 2018 were as follows: Partners’ Capital Attributable to AB Unitholders Non-Controlling Interests In Consolidated Entities Total Capital (in thousands) Balance as of December 31, 2017 $ 4,061,740 $ 1,564 $ 4,063,304 Comprehensive income: Net income 184,196 54 184,250 Other comprehensive income, net of tax: Unrealized gains on investments — — — Foreign currency translation adjustments 9,904 17 9,921 Changes in employee benefit related items 170 — 170 Comprehensive income 194,270 71 194,341 Distributions to General Partner and unitholders (247,773 ) — (247,773 ) Compensation-related transactions 14,334 — 14,334 Capital contributions to affiliates (1,677 ) — (1,677 ) Distributions to non-controlling interests of our consolidated venture capital fund — (5 ) (5 ) Impact of adoption of revenue recognition standard ASC 606 34,951 — 34,951 Balance as of March 31, 2018 $ 4,055,845 $ 1,630 $ 4,057,475 Changes in capital during the three -month period ended March 31, 2017 were as follows: Partners’ Capital Attributable to AB Unitholders Non-Controlling Interests In Consolidated Entities Total Capital (in thousands) Balance as of December 31, 2016 $ 4,032,017 $ 36,172 $ 4,068,189 Comprehensive income: Net income 139,937 1,632 141,569 Other comprehensive income, net of tax: Unrealized (losses) on investments (18 ) — (18 ) Foreign currency translation adjustments 8,791 76 8,867 Changes in employee benefit related items 189 — 189 Comprehensive income 148,899 1,708 150,607 Distributions to General Partner and unitholders (198,040 ) — (198,040 ) Compensation-related transactions (18,673 ) — (18,673 ) Capital contributions to affiliates (81 ) — (81 ) Distributions to non-controlling interests of our consolidated venture capital fund — (3,137 ) (3,137 ) Balance as of March 31, 2017 $ 3,964,122 $ 34,743 $ 3,998,865

Non-controlling Interests

Non-controlling Interests	3 Months Ended
	Mar. 31, 2018
Noncontrolling Interest [Abstract]
Non-controlling Interests	Non-controlling Interests Non-controlling interest in net income for the three months ended March 31, 2018 and 2017 consisted of the following: Three Months Ended March 31, 2018 2017 (in thousands) Non-redeemable non-controlling interests: Consolidated company-sponsored investment funds $ (42 ) $ 1,485 Other 98 147 Total non-redeemable non-controlling interests 56 1,632 Redeemable non-controlling interests: Consolidated company-sponsored investment funds 22,594 14,686 Total non-controlling interest in net income $ 22,650 $ 16,318 Non-redeemable non-controlling interest as of March 31, 2018 and December 31, 2017 consisted of the following: March 31, 2018 December 31, 2017 (in thousands) Consolidated company-sponsored investment funds $ 710 $ 757 CPH Capital Fondsmaeglerselskab A/S 920 807 Total non-redeemable non-controlling interest $ 1,630 $ 1,564 Redeemable non-controlling interest as of March 31, 2018 and December 31, 2017 consisted of the following: March 31, 2018 December 31, 2017 (in thousands) Consolidated company-sponsored investment funds $ 991,602 $ 596,223 CPH Capital Fondsmaeglerselskab A/S acquisition 5,364 5,364 Total redeemable non-controlling interest $ 996,966 $ 601,587

Business Description Organiza25

Business Description Organization and Basis of Presentation (Policies)	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The interim condensed consolidated financial statements have been prepared in accordance with the instructions to Form 10-Q pursuant to the rules and regulations of the U.S. Securities and Exchange Commission (“SEC”). In the opinion of management, all adjustments, consisting only of normal recurring adjustments, necessary for a fair statement of the interim results, have been made. The preparation of the condensed consolidated financial statements requires management to make certain estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the dates of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the interim reporting periods. Actual results could differ from those estimates. The condensed consolidated statement of financial condition as of December 31, 2017 was derived from audited financial statements, but does not include all disclosures required by accounting principles generally accepted in the United States of America (“GAAP”).
Principles of Consolidation	Principles of Consolidation The condensed consolidated financial statements include AB and its majority-owned and/or controlled subsidiaries, and the consolidated entities that are considered to be variable interest entities (“VIEs”) and voting interest entities (“VOEs”) in which AB has a controlling financial interest. Non-controlling interests on the condensed consolidated statements of financial condition include the portion of consolidated company-sponsored investment funds in which we do not have direct equity ownership. All significant inter-company transactions and balances among the consolidated entities have been eliminated.
Reclassification	Reclassification During 2018, prior period amounts for payments to financial intermediaries for administrative services, sub-accounting services and maintenance of books and records for certain funds previously presented as distribution-related payments are now presented as trade execution, marketing, T&E and other expenses in the condensed consolidated statements of income to conform to the current period's presentation.
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Codification (“ASC”) 606, Revenue from Contracts with Customers , which outlines a single comprehensive revenue recognition model for all contracts with customers and supersedes most of the existing revenue recognition requirements. We adopted this new standard on January 1, 2018 on a modified retrospective basis for contracts that were not completed as of the date of adoption. The new standard did not change the timing of revenue recognition for our base fees, distribution revenues, shareholder servicing fees and broker-dealer revenues. However, performance-based fees, which, prior to the adoption of ASC 606, were recognized at the end of the applicable measurement period when no risk of reversal remained, and carried-interest distributions received (considered performance-based fees), recorded as deferred revenues until no risk of reversal remained, may in certain instances be recognized earlier under the new standard, if it is probable that significant reversal of performance-based fees recognized will not occur. On January 1, 2018, we recorded a cumulative effect adjustment, net of tax, of a $35.0 million increase to partners’ capital in the condensed consolidated statement of financial condition. This amount represents carried-interest distributions of $77.9 million previously received, net of revenue sharing payments to investment team-members of $42.7 million , with respect to which it is probable that significant reversal will not occur. In January 2016, the FASB issued ASU 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities . The amendment addresses certain aspects of recognition, measurement, presentation and disclosure of financial instruments. We adopted this standard on January 1, 2018. The adoption of this standard did not have a material impact on our financial condition or results of operations. In August 2016, the FASB issued ASU 2016-15, Statement of Cash Flows (Topic 230) . The amendment is intended to reduce diversity in practice in how certain transactions are classified in the statement of cash flows. We adopted this standard on January 1, 2018. The adoption of this standard did not have a material impact on our financial condition or results of operations. In November 2016, the FASB issued ASU 2016-18, Statement of Cash Flows (Topic 230): Restricted Cash . The new standard requires that the statement of cash flows explain the change during the period in the total of cash, cash equivalents, and amounts generally described as restricted cash or restricted cash equivalents. Companies are also required to reconcile such total amounts in the balance sheet and disclose the nature of the restrictions. We adopted this standard on January 1, 2018. The adoption of this standard did not have a material impact on our financial condition or results of operations. In March 2017, the FASB issued ASU 2017-07, Improving the Presentation of Net Periodic Pension Cost and Net Periodic Postretirement Benefit Cost . The amendment requires that an employer disaggregate the service cost component from the other components of net benefit costs on the income statement. We adopted this standard on January 1, 2018. The adoption of this standard did not have a material impact on our financial condition or results of operations. In May 2017, the FASB issued ASU 2017-09, Compensation - Stock Compensation, Scope of Modification Accounting . The amendment provides clarity and reduces both diversity in practice and cost and complexity when applying the guidance in Topic 718, Compensation - Stock Compensation, to a change to the terms or conditions of a share-based payment award. We adopted this standard on January 1, 2018. The adoption of this standard did not have a material impact on our financial condition or results of operations. Accounting Pronouncements Not Yet Adopted In February 2016, the FASB issued ASU 2016-02, Leases . The amendment requires recognition of lease assets and lease liabilities on the statement of financial condition and disclosure of key information about leasing arrangements. Specifically, this guidance requires an operating lease lessee to recognize on the statement of financial condition a liability to make lease payments and a right-of-use asset representing its right to use the underlying asset for the lease term. However, for leases with a term of twelve months or less, a lessee is permitted to make an accounting policy election not to recognize lease assets and lease liabilities. The amendment is effective for fiscal years (and interim periods within those years) beginning after December 15, 2018 and requires lessees to recognize and measure leases at the beginning of the earliest period presented in the financial statements using a modified retrospective approach. Management currently is evaluating the impact that the adoption of this standard will have on our consolidated financial statements. In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment . The guidance removes Step 2 of the goodwill impairment test, which requires a hypothetical purchase price allocation. As a result of the revised guidance, a goodwill impairment will be the amount by which a reporting unit's carrying value exceeds its fair value, not to exceed the carrying amount of goodwill. The revised guidance will be applied prospectively, and is effective in 2020. The revised guidance is not expected to have a material impact on our financial condition or results of operations. In February 2018, the FASB issued ASU 2018-02, Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income, which permits a company to reclassify the disproportionate income tax effects of the 2017 Tax Cuts and Job Act ("2017 Tax Act") on items within Accumulated Other Comprehensive Income ("AOCI") to retained earnings. The FASB refers to these amounts as "stranded tax effects." The ASU also requires certain new disclosures, some of which are applicable for all companies. The guidance is effective for all companies for fiscal years beginning after December 15, 2018, and interim periods within those fiscal years. Companies may adopt the new guidance using one of two transition methods: (1) retrospective to each period (or periods) in which the income tax effect of the 2017 Tax Act related to items remaining in AOCI are recognized, or (2) at the beginning of the period of adoption. The adoption of this standard is not expected to have a material impact on our financial condition or results of operations. Revenue Recognition Investment advisory and services fees AB provides asset management services by managing customer assets and seeking to deliver investment returns to investors. Each investment management contract between AB and a customer creates a distinct, separately identifiable performance obligation for each day the customer’s assets are managed as the customer can benefit from each day of service. In accordance with ASC 606, a series of distinct goods and services that are substantially the same and have the same pattern of transfer to the customer are treated as a single performance obligation. Accordingly, we have determined that our investment and advisory services are performed over time and entitle us to variable consideration earned based upon the value of the investors’ assets under management (“AUM”). We calculate AUM using established market-based valuation methods and fair valuation (non-observable market) methods. Market-based valuation methods include: last sale/settle prices from an exchange for actively-traded listed equities, options and futures; evaluated bid prices from recognized pricing vendors for fixed income, asset-backed or mortgage-backed issues; mid prices from recognized pricing vendors and brokers for credit default swaps; and quoted bids or spreads from pricing vendors and brokers for other derivative products. Fair valuation methods include: discounted cash flow models, evaluation of assets versus liabilities or any other methodology that is validated and approved by our Valuation Committee ( see paragraph immediately below for additional information about our Valuation Committee). Fair valuation methods are used only where AUM cannot be valued using market-based valuation methods, such as in the case of private equity or illiquid securities. The Valuation Committee, which consists of senior officers and employees, is responsible for overseeing the pricing and valuation of all investments held in client and AB portfolios. The Valuation Committee has adopted a Statement of Pricing Policies describing principles and policies that apply to pricing and valuing investments held in these portfolios. We also have a Pricing Group, which reports to the Valuation Committee, and is responsible for overseeing the pricing process for all investments. We record as revenue investment advisory and services base fees, which we generally calculate as a percentage of AUM. At month-end, all the components of the transaction price (i.e. the base fee calculation) are no longer variable and the value of the consideration is determined. These fees are not subject to claw back and there is minimal probability that a significant reversal of the revenue recorded will occur. The transaction price for the asset management performance obligation for certain investment advisory contracts, including those associated with hedge funds or other alternative investments, provide for a performance-based fee (including carried interest), in addition to a base advisory fee, which is calculated as either a percentage of absolute investment results or a percentage of investment results in-excess-of a stated benchmark over a specified period-of-time. The performance-based fees are forms of variable consideration and are therefore excluded from the transaction price until it becomes probable that there will not be significant reversal of the cumulative revenue recognized. At each reporting date, we evaluate the constraining factors, discussed below , surrounding the variable consideration to determine the extent to which, if any, that revenues associated with the performance-based fee can be recognized. Constraining factors impacting the amount of variable consideration included in the transaction price include: the contractual claw-back provisions the variable consideration is subject to, the length of time the uncertainty of the consideration is subject to, the number and range of possible consideration amounts, the probability of significant fluctuations in the fund’s market value, the level at which the fund’s value exceeds the contractual threshold required to earn such a fee and the materiality of the amount being evaluated. Prior to the adoption of ASC 606 on January 1, 2018, we recognized performance-based fees at the end of the applicable measurement period when no risk of reversal remained, and carried-interest distributions received as deferred revenues until no risk of reversal remained. Bernstein Research Services Bernstein Research Services revenue consists principally of commissions received for trade execution services and providing equity research services to institutional clients. Brokerage commissions for trade execution services and related expenses are recorded on a trade-date basis when the performance obligations are satisfied. Generally, the transaction price is agreed upon at the point of each trade and based upon the number of shares traded or the value of the consideration traded. Research revenues are recognized when the transaction price is quantified, collectability is assured and that significant reversal of such revenue is not probable. Distribution Revenues Two of our subsidiaries act as distributors and/or placement agents of company-sponsored mutual funds and receive distribution services fees from certain of those funds as partial reimbursement of the distribution expenses they incur. Depending upon the contractual arrangements with the customer and the specific product sold, the variable consideration can be determined in different ways, as discussed below , as we satisfy the performance obligation. Most open-end U.S. funds have adopted a plan under Rule 12b-1 of the Investment Company Act that allows the fund to pay, out of assets of the fund, distribution and service fees for the distribution and sale of its shares (“Rule 12b-1 Fees”). The open-end U.S. funds have such agreements with us, and we have selling and distribution agreements pursuant to which we pay sales commissions to the financial intermediaries that distribute our open-end U.S. funds. These agreements are terminable by either party upon notice (generally 30 days) and do not obligate the financial intermediary to sell any specific amount of fund shares. We record 12b-1 fees monthly based upon a percentage of the net asset value (“NAV”) of the funds. At month-end, the variable consideration of the transaction price is no longer constrained as the NAV can be calculated and the value of consideration is determined. These services are separate and distinct from other asset management services as the customer can benefit from these services independently of other services. We accrue the corresponding 12b-1 fees paid to sub-distributors monthly as the expenses are incurred. We are acting in a principal capacity in these transactions; as such, these revenues and expenses are recorded on a gross basis. We offer back-end load shares in limited instances and charge the investor a contingent deferred sales charge (“CDSC”) if the investment is redeemed within a certain period. The variable consideration for these contracts is contingent upon the timing of the redemption by the investor and the value of the sale proceeds. Due to these constraining factors, we exclude the CDSC fee from the transaction price until the investor redeems the investment. Upon redemption, the cash consideration received for these contractual arrangements are recorded as reductions of unamortized deferred sales commissions. Our Luxembourg subsidiary, the management company for most of our non-U.S. funds, earns a management fee which is accrued daily and paid monthly, at an annual rate, based on the average daily net assets of the fund. With respect to certain share classes, the management fee may also contain a component that is paid to distributors and other financial intermediaries and service providers to cover shareholder servicing and other administrative expenses (also referred to as an All-in-Fee). As we have concluded that asset management is distinct from distribution, we allocate a portion of the investment and advisory fee to distribution revenues for the servicing component based on standalone selling prices. Other Revenues Revenues from contracts with customers include a portion of other revenues, which consists primarily of shareholder servicing fees, as well as mutual fund reimbursements and other brokerage income. We provide shareholder services, which include transfer agency, administrative and recordkeeping services provided to company-sponsored mutual funds. The consideration for these services is based on a percentage of the NAV of the fund or a fixed-fee based on the number of shareholder accounts being serviced. The revenues are recorded at month-end when the constraining factors involved with determining NAV or the number of shareholders’ accounts are resolved. Non-Contractual Revenues Dividend and interest income is accrued as earned. Investment gains and losses on the condensed consolidated statements of income include unrealized gains and losses of trading and private equity investments stated at fair value, equity in earnings of our limited partnership hedge fund investments, and realized gains and losses on investments sold. Contract Assets and Liabilities We use the practical expedient for contracts that have an original duration of one year or less. Accordingly, we do not consider the time value of money and, instead, accrue the incremental costs of obtaining the contract when incurred. As of March 31, 2018, the balances of contract assets and contract liabilities are not considered material and, accordingly, no further disclosures are necessary.

Business Description Organiza26

Business Description Organization and Basis of Presentation (Tables)	3 Months Ended
	Mar. 31, 2018
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Ownership Structure of AB as a Percentage of General and Limited Partnership Interests	As of March 31, 2018 , the ownership structure of AB, including limited partnership units outstanding as well as the general partner's 1% interest, is as follows: AXA and its subsidiaries 63.0 % AB Holding 35.8 Unaffiliated holders 1.2 100.0 %

Revenue Recognition (Tables)

Revenue Recognition (Tables)	3 Months Ended
	Mar. 31, 2018
Revenue from Contract with Customer [Abstract]
Revenues	Revenues for the three months ended March 31, 2018 and 2017 consisted of the following: Three Months Ended March 31, 2018 2017 (in thousands) Subject to contracts with customers: Investment advisory and services fees Base fees $ 567,338 $ 492,176 Performance-based fees 6,260 6,114 Bernstein research services 114,400 112,741 Distribution revenues All-in-management fees 66,748 54,519 12b-1 fees 22,534 24,789 Other 18,722 17,246 Other revenues Shareholder servicing fees 19,530 17,964 Other 5,628 3,952 821,160 729,501 Not subject to contracts with customers: Dividend and interest income, net of interest expense 18,675 9,766 Investment gains (losses) 26,082 25,201 Other revenues 1,870 449 46,627 35,416 Total net revenues $ 867,787 $ 764,917

Real Estate Charges (Tables)

Real Estate Charges (Tables)	3 Months Ended
	Mar. 31, 2018
Restructuring and Related Activities [Abstract]
Real Estate Liability Account Activity Related to Office Space Consolidation Initiatives	The activity in the liability account relating to our global space consolidation initiatives for the following periods is: Three Months Ended Twelve Months Ended (in thousands) Balance as of beginning of period $ 113,635 $ 112,932 Expense incurred (264 ) 28,507 Deferred rent — 7,083 Payments made (8,981 ) (39,122 ) Interest accretion 1,090 4,235 Balance as of end of period $ 105,480 $ 113,635

Net Income per Unit (Tables)

Net Income per Unit (Tables)	3 Months Ended
	Mar. 31, 2018
Earnings Per Unit [Abstract]
Schedule of Earnings Per Unit, Basic and Diluted	Basic net income per unit is derived by reducing net income for the 1% general partnership interest and dividing the remaining 99% by the basic weighted average number of limited partnership units outstanding for each period. Diluted net income per unit is derived by reducing net income for the 1% general partnership interest and dividing the remaining 99% by the total of the diluted weighted average number of limited partnership units outstanding for each period. Three Months Ended March 31, 2018 2017 (in thousands, except per unit amounts) Net income attributable to AB Unitholders $ 184,196 $ 139,937 Weighted average limited partnership units outstanding – basic 269,184 268,479 Dilutive effect of compensatory options to buy AB Holding Units 336 534 Weighted average limited partnership units outstanding – diluted 269,520 269,013 Basic net income per AB Unit $ 0.68 $ 0.52 Diluted net income per AB Unit $ 0.68 $ 0.51

Investments (Tables)

Investments (Tables)	3 Months Ended
	Mar. 31, 2018
Investments, Debt and Equity Securities [Abstract]
Summary of Investments	Investments consist of: March 31, December 31, (in thousands) U.S. Treasury Bills $ 52,685 $ 52,609 Equity securities: Long-term incentive compensation-related 42,022 51,758 Seed capital 137,033 160,672 Other 74,177 81,154 Exchange-traded options 5,395 4,981 Investments in limited partnership hedge funds: Long-term incentive compensation-related 14,378 14,276 Seed capital 24,734 22,923 Private equity (seed capital) 38,011 38,186 Time deposits 5,160 5,138 Other 11,786 11,892 Total investments $ 405,381 $ 443,589
Portion of Unrealized Gains (Losses) Related to Equity Securities	The portion of unrealized gains (losses) for the three months ended March 31, 2018 and 2017 related to equity securities held as of March 31, 2018 and 2017 were as follows: Three Months Ended March 31, 2018 2017 (in thousands) Net (losses) gains recognized during the period $ (1,823 ) $ 14,189 Less: net gains recognized during the period on equity securities sold during the period 1,282 1,408 Unrealized (losses) gains recognized during the period on equity securities held $ (3,105 ) $ 12,781

Derivative Instruments (Tables)

Derivative Instruments (Tables)	3 Months Ended
	Mar. 31, 2018
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Notional and Fair Value for Derivative Instruments Not Designated as Hedging Instruments	The notional value and fair value as of March 31, 2018 and December 31, 2017 for derivative instruments (excluding derivative instruments relating to our options desk trading activities discussed below ) not designated as hedging instruments were as follows: Fair Value Notional Value Asset Derivatives Liability Derivatives (in thousands) March 31, 2018: Exchange-traded futures $ 178,462 $ 1,517 $ 1,240 Currency forwards 157,448 8,286 8,347 Interest rate swaps 50,403 843 659 Credit default swaps 78,741 1,403 2,410 Total return swaps 135,655 1,516 450 Total derivatives $ 600,709 $ 13,565 $ 13,106 December 31, 2017: Exchange-traded futures $ 163,458 $ 948 $ 2,540 Currency forwards 126,503 8,306 8,058 Interest rate swaps 43,309 951 870 Credit default swaps 74,600 1,247 2,465 Total return swaps 68,106 167 390 Total derivatives $ 475,976 $ 11,619 $ 14,323
Gains and Losses for Derivative Instruments Recognized in Investment Gains (Losses) in the Condensed Consolidated Statements of Income	The gains and losses for derivative instruments (excluding our options desk trading activities discussed below ) for the three months ended March 31, 2018 and 2017 recognized in investment gains (losses) in the condensed consolidated statements of income were as follows: Three Months Ended March 31, 2018 2017 (in thousands) Exchange-traded futures $ 825 $ (5,532 ) Currency forwards 17 (1,062 ) Interest rate swaps 274 (97 ) Credit default swaps 74 (672 ) Total return swaps 1,177 (2,129 ) Net gains (losses) on derivative instruments $ 2,367 $ (9,492 )

Offsetting Assets and Liabili32

Offsetting Assets and Liabilities (Tables)	3 Months Ended
	Mar. 31, 2018
Offsetting [Abstract]
Schedule of Offsetting of Financial Assets	Offsetting of assets as of March 31, 2018 and December 31, 2017 was as follows: Gross Amounts of Recognized Assets Gross Amounts Offset in the Statement of Financial Condition Net Amounts of Assets Presented in the Statement of Financial Condition Financial Instruments Cash Collateral Received Net Amount (in thousands) March 31, 2018: Securities borrowed $ 48,302 $ — $ 48,302 $ (46,858 ) $ — $ 1,444 Derivatives $ 13,565 $ — $ 13,565 $ — $ (2,364 ) $ 11,201 Long exchange-traded options $ 5,395 $ — $ 5,395 $ — $ — $ 5,395 December 31, 2017: Securities borrowed $ 85,371 $ — $ 85,371 $ (82,353 ) $ — $ 3,018 Derivatives $ 11,619 $ — $ 11,619 $ — $ (519 ) $ 11,100 Long exchange-traded options $ 4,981 $ — $ 4,981 $ — $ — $ 4,981
Schedule of Offsetting of Financial Liabilities	Offsetting of liabilities as of March 31, 2018 and December 31, 2017 was as follows: Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Statement of Financial Condition Net Amounts of Liabilities Presented in the Statement of Financial Condition Financial Instruments Cash Collateral Pledged Net Amount (in thousands) March 31, 2018: Securities loaned $ 20,500 $ — $ 20,500 $ (20,500 ) $ — $ — Derivatives $ 13,106 $ — $ 13,106 $ — $ (4,724 ) $ 8,382 Short exchange-traded options $ 13,966 $ — $ 13,966 $ — $ — $ 13,966 December 31, 2017: Securities loaned $ 37,960 $ — $ 37,960 $ (37,922 ) $ — $ 38 Derivatives $ 14,323 $ — $ 14,323 $ — $ (8,794 ) $ 5,529 Short exchange-traded options $ 13,585 $ — $ 13,585 $ — $ — $ 13,585

Fair Value (Tables)

Fair Value (Tables)	3 Months Ended
	Mar. 31, 2018
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis	Valuation of our financial instruments by pricing observability levels as of March 31, 2018 and December 31, 2017 was as follows (in thousands): Level 1 Level 2 Level 3 NAV Expedient (1) Other Total March 31, 2018: Money markets $ 48,942 $ — $ — $ — $ — $ 48,942 Securities segregated (U.S. Treasury Bills) — 1,024,529 — — — 1,024,529 Derivatives 1,517 12,048 — — — 13,565 Investments U.S. Treasury Bills — 52,685 — — — 52,685 Equity securities 237,169 15,533 117 413 — 253,232 Long exchange-traded options 5,395 — — — — 5,395 Limited partnership hedge funds (2) — — — — 39,112 39,112 Private equity — — 954 37,057 — 38,011 Time deposits (3) — — — — 5,160 5,160 Other investments — — — — 11,786 11,786 Total investments 242,564 68,218 1,071 37,470 56,058 405,381 Total assets measured at fair value $ 293,023 $ 1,104,795 $ 1,071 $ 37,470 $ 56,058 $ 1,492,417 Securities sold not yet purchased Short equities – corporate $ 13,567 $ — $ — $ — $ — $ 13,567 Short exchange-traded options 13,966 — — — — 13,966 Derivatives 1,240 11,866 — — — 13,106 Contingent payment arrangements — — 10,908 — — 10,908 Total liabilities measured at fair value $ 28,773 $ 11,866 $ 10,908 $ — $ — $ 51,547 December 31, 2017: Money markets $ 62,071 $ — $ — $ — $ — $ 62,071 Securities segregated (U.S. Treasury Bills) — 816,350 — — — 816,350 Derivatives 948 10,671 — — — 11,619 Investments U.S. Treasury Bills — 52,609 — — — 52,609 Equity securities 276,755 16,618 117 94 — 293,584 Long exchange-traded options 4,981 — — — — 4,981 Limited partnership hedge funds (2) — — — — 37,199 37,199 Private equity — — 954 37,232 — 38,186 Time deposits (3) — — — — 5,138 5,138 Other investments — — — — 11,892 11,892 Total investments 281,736 69,227 1,071 37,326 54,229 443,589 Total assets measured at fair value $ 344,755 $ 896,248 $ 1,071 $ 37,326 $ 54,229 $ 1,333,629 Securities sold not yet purchased Short equities – corporate $ 16,376 $ — $ — $ — $ — $ 16,376 Short exchange-traded options 13,585 — — — — 13,585 Derivatives 2,540 11,783 — — — 14,323 Contingent payment arrangements — — 10,855 — — 10,855 Total liabilities measured at fair value $ 32,501 $ 11,783 $ 10,855 $ — $ — $ 55,139 (1) Investments measured at fair value using NAV (or its equivalent) as a practical expedient. (2) Investments in equity method investees that are not measured at fair value in accordance with GAAP. (3) Investments carried at amortized cost that are not measured at fair value in accordance with GAAP.
Schedule of Change in Carrying Value Level 3 Financial Instruments	The change in carrying value associated with Level 3 financial instruments carried at fair value, classified as private equity and trading equity securities, is as follows: Three Months Ended March 31, 2018 2017 (in thousands) Balance as of beginning of period $ 1,071 $ 5,023 Purchases — — Sales — — Realized gains (losses), net — — Unrealized gains (losses), net — 3 Balance as of end of period $ 1,071 $ 5,026
Schedule of Contingent Payment Arrangements Level 3 Financial Instruments	The change in carrying value associated with Level 3 financial instruments carried at fair value, classified as contingent payment arrangements, is as follows: Three Months Ended March 31, 2018 2017 (in thousands) Balance as of beginning of period $ 10,855 $ 17,589 Accretion 53 178 Payments — (590 ) Balance as of end of period $ 10,908 $ 17,177

Consolidated Company-Sponsore34

Consolidated Company-Sponsored Investment Funds (Tables)	3 Months Ended
	Mar. 31, 2018
Variable Interest Entity [Line Items]
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis	Valuation of our financial instruments by pricing observability levels as of March 31, 2018 and December 31, 2017 was as follows (in thousands): Level 1 Level 2 Level 3 NAV Expedient (1) Other Total March 31, 2018: Money markets $ 48,942 $ — $ — $ — $ — $ 48,942 Securities segregated (U.S. Treasury Bills) — 1,024,529 — — — 1,024,529 Derivatives 1,517 12,048 — — — 13,565 Investments U.S. Treasury Bills — 52,685 — — — 52,685 Equity securities 237,169 15,533 117 413 — 253,232 Long exchange-traded options 5,395 — — — — 5,395 Limited partnership hedge funds (2) — — — — 39,112 39,112 Private equity — — 954 37,057 — 38,011 Time deposits (3) — — — — 5,160 5,160 Other investments — — — — 11,786 11,786 Total investments 242,564 68,218 1,071 37,470 56,058 405,381 Total assets measured at fair value $ 293,023 $ 1,104,795 $ 1,071 $ 37,470 $ 56,058 $ 1,492,417 Securities sold not yet purchased Short equities – corporate $ 13,567 $ — $ — $ — $ — $ 13,567 Short exchange-traded options 13,966 — — — — 13,966 Derivatives 1,240 11,866 — — — 13,106 Contingent payment arrangements — — 10,908 — — 10,908 Total liabilities measured at fair value $ 28,773 $ 11,866 $ 10,908 $ — $ — $ 51,547 December 31, 2017: Money markets $ 62,071 $ — $ — $ — $ — $ 62,071 Securities segregated (U.S. Treasury Bills) — 816,350 — — — 816,350 Derivatives 948 10,671 — — — 11,619 Investments U.S. Treasury Bills — 52,609 — — — 52,609 Equity securities 276,755 16,618 117 94 — 293,584 Long exchange-traded options 4,981 — — — — 4,981 Limited partnership hedge funds (2) — — — — 37,199 37,199 Private equity — — 954 37,232 — 38,186 Time deposits (3) — — — — 5,138 5,138 Other investments — — — — 11,892 11,892 Total investments 281,736 69,227 1,071 37,326 54,229 443,589 Total assets measured at fair value $ 344,755 $ 896,248 $ 1,071 $ 37,326 $ 54,229 $ 1,333,629 Securities sold not yet purchased Short equities – corporate $ 16,376 $ — $ — $ — $ — $ 16,376 Short exchange-traded options 13,585 — — — — 13,585 Derivatives 2,540 11,783 — — — 14,323 Contingent payment arrangements — — 10,855 — — 10,855 Total liabilities measured at fair value $ 32,501 $ 11,783 $ 10,855 $ — $ — $ 55,139 (1) Investments measured at fair value using NAV (or its equivalent) as a practical expedient. (2) Investments in equity method investees that are not measured at fair value in accordance with GAAP. (3) Investments carried at amortized cost that are not measured at fair value in accordance with GAAP.
Schedule of Change in Carrying Value Level 3 Financial Instruments	The change in carrying value associated with Level 3 financial instruments carried at fair value, classified as private equity and trading equity securities, is as follows: Three Months Ended March 31, 2018 2017 (in thousands) Balance as of beginning of period $ 1,071 $ 5,023 Purchases — — Sales — — Realized gains (losses), net — — Unrealized gains (losses), net — 3 Balance as of end of period $ 1,071 $ 5,026
Schedule of Offsetting of Derivative Assets	Offsetting of assets as of March 31, 2018 and December 31, 2017 was as follows: Gross Amounts of Recognized Assets Gross Amounts Offset in the Statement of Financial Condition Net Amounts of Assets Presented in the Statement of Financial Condition Financial Instruments Cash Collateral Received Net Amount (in thousands) March 31, 2018: Securities borrowed $ 48,302 $ — $ 48,302 $ (46,858 ) $ — $ 1,444 Derivatives $ 13,565 $ — $ 13,565 $ — $ (2,364 ) $ 11,201 Long exchange-traded options $ 5,395 $ — $ 5,395 $ — $ — $ 5,395 December 31, 2017: Securities borrowed $ 85,371 $ — $ 85,371 $ (82,353 ) $ — $ 3,018 Derivatives $ 11,619 $ — $ 11,619 $ — $ (519 ) $ 11,100 Long exchange-traded options $ 4,981 $ — $ 4,981 $ — $ — $ 4,981
Schedule of Offsetting of Derivative Liabilities	Offsetting of liabilities as of March 31, 2018 and December 31, 2017 was as follows: Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Statement of Financial Condition Net Amounts of Liabilities Presented in the Statement of Financial Condition Financial Instruments Cash Collateral Pledged Net Amount (in thousands) March 31, 2018: Securities loaned $ 20,500 $ — $ 20,500 $ (20,500 ) $ — $ — Derivatives $ 13,106 $ — $ 13,106 $ — $ (4,724 ) $ 8,382 Short exchange-traded options $ 13,966 $ — $ 13,966 $ — $ — $ 13,966 December 31, 2017: Securities loaned $ 37,960 $ — $ 37,960 $ (37,922 ) $ — $ 38 Derivatives $ 14,323 $ — $ 14,323 $ — $ (8,794 ) $ 5,529 Short exchange-traded options $ 13,585 $ — $ 13,585 $ — $ — $ 13,585
Company-sponsored investment funds
Variable Interest Entity [Line Items]
Balances of Consolidated VIEs and VOEs included in Statement of Financial Condition	The balances of consolidated VIEs and VOEs included in our condensed consolidated statements of financial condition were as follows: March 31, 2018 December 31, 2017 (in thousands) VIEs VOEs Total VIEs VOEs Total Cash and cash equivalents $ 580,239 $ 482 $ 580,721 $ 326,158 $ 360 $ 326,518 Investments 1,826,576 129,894 1,956,470 1,189,835 56,448 1,246,283 Other assets 40,242 4,250 44,492 33,931 1,466 35,397 Total assets $ 2,447,057 $ 134,626 $ 2,581,683 $ 1,549,924 $ 58,274 $ 1,608,198 Liabilities $ 1,218,612 $ 4,262 $ 1,222,874 $ 695,997 $ 2,104 $ 698,101 Redeemable non-controlling interest 981,961 9,641 991,602 596,241 (18 ) 596,223 Partners' capital attributable to AB Unitholders 245,774 120,723 366,497 256,929 56,188 313,117 Non-redeemable non-controlling interests in consolidated entities 710 — 710 757 — 757 Total liabilities, redeemable non-controlling interest and partners' capital $ 2,447,057 $ 134,626 $ 2,581,683 $ 1,549,924 $ 58,274 $ 1,608,198
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis	Valuation of consolidated company-sponsored investment funds' financial instruments by pricing observability levels as of March 31, 2018 and December 31, 2017 was as follows (in thousands): Level 1 Level 2 Level 3 NAV Expedient Total March 31, 2018: Investments - VIEs $ 1,612,691 $ 208,118 $ 5,767 $ — $ 1,826,576 Investments - VOEs 77,172 52,588 134 — 129,894 Derivatives - VIEs 769 30,237 — — 31,006 Derivatives - VOEs 43 595 — — 638 Total assets measured at fair value $ 1,690,675 $ 291,538 $ 5,901 $ — $ 1,988,114 Short equities - VIEs $ 1,188,624 $ — $ — $ — $ 1,188,624 Derivatives - VIEs 1,027 17,373 — — 18,400 Derivatives - VOEs 89 587 — — 676 Total liabilities measured at fair value $ 1,189,740 $ 17,960 $ — $ — $ 1,207,700 December 31, 2017: Investments - VIEs $ 1,053,824 $ 133,796 $ 2,205 $ 10 $ 1,189,835 Investments - VOEs 5,491 50,898 59 — 56,448 Derivatives - VIEs 252 30,384 — — 30,636 Derivatives - VOEs 49 251 — — 300 Total assets measured at fair value $ 1,059,616 $ 215,329 $ 2,264 $ 10 $ 1,277,219 Short equities - VIEs $ 669,258 $ — $ — $ — $ 669,258 Derivatives - VIEs 421 21,820 — — 22,241 Derivatives - VOEs 12 619 — — 631 Total liabilities measured at fair value $ 669,691 $ 22,439 $ — $ — $ 692,130
Schedule of Change in Carrying Value Level 3 Financial Instruments	The change in carrying value associated with Level 3 financial instruments carried at fair value within consolidated company-sponsored investment funds was as follows: Three Months Ended March 31, 2018 2017 (in thousands) Balance as of beginning of period $ 2,264 $ 5,741 Transfers (out) in (13 ) 749 Purchases 4,034 4,577 Sales (333 ) (1,073 ) Realized gains (losses), net 5 (12 ) Unrealized (losses) gains, net (58 ) 271 Accrued discounts 2 20 Balance as of end of period $ 5,901 $ 10,273
Schedule of Offsetting of Derivative Assets	Offsetting of derivative assets of consolidated company-sponsored investment funds as of March 31, 2018 and December 31, 2017 was as follows: Gross Amounts of Recognized Assets Gross Amounts Offset in the Statement of Financial Condition Net Amounts of Assets Presented in the Statement of Financial Condition Financial Instruments Cash Collateral Received Net Amount (in thousands) March 31, 2018: Derivatives - VIEs $ 31,006 $ — $ 31,006 $ — $ (2,271 ) $ 28,735 Derivatives - VOEs $ 638 $ — $ 638 $ — $ (47 ) $ 591 December 31, 2017: Derivatives - VIEs $ 30,636 $ — $ 30,636 $ — $ (194 ) $ 30,442 Derivatives - VOEs $ 300 $ — $ 300 $ — $ (37 ) $ 263
Schedule of Offsetting of Derivative Liabilities	Offsetting of derivative liabilities of consolidated company-sponsored investment funds as of March 31, 2018 and December 31, 2017 was as follows: Gross Amounts of Recognized Liabilities Gross Amounts Offset in the Statement of Financial Condition Net Amounts of Liabilities Presented in the Statement of Financial Condition Financial Instruments Cash Collateral Pledged Net Amount (in thousands) March 31, 2018: Derivatives - VIEs $ 18,400 $ — $ 18,400 $ — $ (1,372 ) $ 17,028 Derivatives - VOEs $ 676 $ — $ 676 $ — $ (253 ) $ 423 December 31, 2017: Derivatives - VIEs $ 22,241 $ — $ 22,241 $ — $ (2,884 ) $ 19,357 Derivatives - VOEs $ 631 $ — $ 631 $ — $ (228 ) $ 403

Units Outstanding (Tables)

Units Outstanding (Tables)	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Changes in AB Units Outstanding	Changes in AB Units outstanding during the three -month period ended March 31, 2018 were as follows: Outstanding as of December 31, 2017 268,659,333 Options exercised 235,105 Units issued 949,185 Units retired (1) (3,686 ) Balance as of March 31, 2018 269,839,937 (1) Includes 1,150 AB Units purchased in private transactions and retired during the first three months of 2018 .

Changes in Capital (Tables)

Changes in Capital (Tables)	3 Months Ended
	Mar. 31, 2018
Equity [Abstract]
Summary of Changes in Capital	Changes in capital during the three -month period ended March 31, 2018 were as follows: Partners’ Capital Attributable to AB Unitholders Non-Controlling Interests In Consolidated Entities Total Capital (in thousands) Balance as of December 31, 2017 $ 4,061,740 $ 1,564 $ 4,063,304 Comprehensive income: Net income 184,196 54 184,250 Other comprehensive income, net of tax: Unrealized gains on investments — — — Foreign currency translation adjustments 9,904 17 9,921 Changes in employee benefit related items 170 — 170 Comprehensive income 194,270 71 194,341 Distributions to General Partner and unitholders (247,773 ) — (247,773 ) Compensation-related transactions 14,334 — 14,334 Capital contributions to affiliates (1,677 ) — (1,677 ) Distributions to non-controlling interests of our consolidated venture capital fund — (5 ) (5 ) Impact of adoption of revenue recognition standard ASC 606 34,951 — 34,951 Balance as of March 31, 2018 $ 4,055,845 $ 1,630 $ 4,057,475 Changes in capital during the three -month period ended March 31, 2017 were as follows: Partners’ Capital Attributable to AB Unitholders Non-Controlling Interests In Consolidated Entities Total Capital (in thousands) Balance as of December 31, 2016 $ 4,032,017 $ 36,172 $ 4,068,189 Comprehensive income: Net income 139,937 1,632 141,569 Other comprehensive income, net of tax: Unrealized (losses) on investments (18 ) — (18 ) Foreign currency translation adjustments 8,791 76 8,867 Changes in employee benefit related items 189 — 189 Comprehensive income 148,899 1,708 150,607 Distributions to General Partner and unitholders (198,040 ) — (198,040 ) Compensation-related transactions (18,673 ) — (18,673 ) Capital contributions to affiliates (81 ) — (81 ) Distributions to non-controlling interests of our consolidated venture capital fund — (3,137 ) (3,137 ) Balance as of March 31, 2017 $ 3,964,122 $ 34,743 $ 3,998,865

Non-controlling Interests (Tabl

Non-controlling Interests (Tables)	3 Months Ended
	Mar. 31, 2018
Noncontrolling Interest [Abstract]
Non-controlling Interest in Net Income	Non-controlling interest in net income for the three months ended March 31, 2018 and 2017 consisted of the following: Three Months Ended March 31, 2018 2017 (in thousands) Non-redeemable non-controlling interests: Consolidated company-sponsored investment funds $ (42 ) $ 1,485 Other 98 147 Total non-redeemable non-controlling interests 56 1,632 Redeemable non-controlling interests: Consolidated company-sponsored investment funds 22,594 14,686 Total non-controlling interest in net income $ 22,650 $ 16,318
Non-redeemable Noncontrolling Interest	Non-redeemable non-controlling interest as of March 31, 2018 and December 31, 2017 consisted of the following: March 31, 2018 December 31, 2017 (in thousands) Consolidated company-sponsored investment funds $ 710 $ 757 CPH Capital Fondsmaeglerselskab A/S 920 807 Total non-redeemable non-controlling interest $ 1,630 $ 1,564
Redeemable Noncontrolling Interest	Redeemable non-controlling interest as of March 31, 2018 and December 31, 2017 consisted of the following: March 31, 2018 December 31, 2017 (in thousands) Consolidated company-sponsored investment funds $ 991,602 $ 596,223 CPH Capital Fondsmaeglerselskab A/S acquisition 5,364 5,364 Total redeemable non-controlling interest $ 996,966 $ 601,587

Business Description Organiza38

Business Description Organization and Basis of Presentation (Details)	3 Months Ended
	Mar. 31, 2018shares
Ownership structure of AllianceBernstein expressed as a percentage of general and limited partnership interests [Abstract]
AXA and its subsidiaries ownership interest in holding company (percent)	3.90%
General partnership information [Abstract]
General Partnership number of general partnership units owned in Holding Company (in units)	100,000
General partnership interest in Company (percent)	1.00%
AXA and its subsidiaries economic interest in Company (percent)	64.40%
Limited partners or members ownership interest in company (percent)	100.00%
AXA and its subsidiaries
General partnership information [Abstract]
Limited partners or members ownership interest in company (percent)	63.00%
AB Holding
General partnership information [Abstract]
Limited partners or members ownership interest in company (percent)	35.80%
Unaffiliated holders
General partnership information [Abstract]
Limited partners or members ownership interest in company (percent)	1.20%

Significant Accounting Polici39

Significant Accounting Policies (Details) - Difference between Revenue Guidance in Effect before and after Topic 606 - Accounting Standards Update 2014-09 - USD ($) $ in Millions	Jan. 01, 2018	Mar. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect adjustment, net of tax, to partner's capital	$ 35	$ 35
Carried-interest distributions previously received	77.9
Revenue sharing payments to investment team-members	$ 42.7

Revenue Recognition (Details)

Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	$ 821,160	$ 729,501
Dividend and interest income, net of interest expense	18,675	9,766
Investment gains (losses)	26,082	25,201
Other Revenue, Net	1,870	449
Revenue not subject to contract with customer	46,627	35,416
Net revenues	867,787	764,917
Base fees
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	567,338	492,176
Performance-based fees
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	6,260	6,114
Bernstein research services
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	114,400	112,741
All-in-management fees
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	66,748	54,519
12b-1 fees
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	22,534	24,789
Other
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	18,722	17,246
Shareholder servicing fees
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	19,530	17,964
Other
Disaggregation of Revenue [Line Items]
Revenue subject to contracts with customers	$ 5,628	$ 3,952

Long-term Incentive Compensat41

Long-term Incentive Compensation Plans (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
AB Holding Units purchased (in units)	100,000	1,300,000
Amount paid for AB Holding Units acquired	$ 2,300	$ 31,000
Open-market purchases of AB Holding Units (in units)		1,200,000
Amount paid for open-market purchases of AB Holding Units		$ 27,800
Restricted AB Holding Units awarded to employees (in units)	1,100,000	1,100,000
Units issued upon exercise of options (in units)	235,105	300,000
Proceeds from stock options exercised	$ 4,009	$ 4,468

Real Estate Charges (Details)

Real Estate Charges (Details) $ in Thousands, ft² in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018USD ($)ft²	Dec. 31, 2017USD ($)
Restructuring and Related Activities [Abstract]
Square feet of office space sub-leased | ft²	1
Real estate liability restructuring reserve [Abstract]
Balance as of beginning of period	$ 113,635	$ 112,932
Expense incurred	(264)	28,507
Deferred rent	0	7,083
Payments made	(8,981)	(39,122)
Interest accretion	1,090	4,235
Balance as of end of period	$ 105,480	$ 113,635

Net Income per Unit (Details)

Net Income per Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Unit [Abstract]
General partnership interest in Company (percent)	1.00%
Limited Partners interest in Company (as a percent)	99.00%
Net income per unit, basic and diluted [Abstract]
Net income attributable to AB Unitholders	$ 184,196	$ 139,937
Weighted average limited partnership units outstanding – basic (in units)	269,184,000	268,479,000
Dilutive effect of compensatory options to buy AB Holding Units (in units)	336,000	534,000
Weighted average limited partnership units outstanding – diluted (in units)	269,520,000	269,013,000
Basic net income per AB Unit (in dollars per unit)	$ 0.68	$ 0.52
Diluted net income per AB Unit (in dollars per unit)	$ 0.68	$ 0.51
Options excluded from diluted net income per unit computation due to their anti-dilutive effect (in units)	1,225,731	2,437,307

Cash Distributions (Details)

Cash Distributions (Details) - USD ($) $ / shares in Units, $ in Millions	Apr. 26, 2018	Apr. 26, 2018	Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018
Distribution Made to Limited Partner [Line Items]
General partnership interest in Company (percent)			1.00%
Diluted net income per AB Unit (in dollars per unit)			$ 0.68	$ 0.51
Subsequent Event
Distribution Made to Limited Partner [Line Items]
Distribution declared (in dollars per unit)	$ 0.80
Difference between diluted net income per unit and distribution per unit (in dollars per unit)		$ 0.12
Cash Distribution
Distribution Made to Limited Partner [Line Items]
Declaration date			Apr. 26, 2018
General partnership interest in Company (percent)			1.00%
Distribution date			May 17, 2018
Date of record			May 7, 2018
Accounting Standards Update 2014-09 | Difference between Revenue Guidance in Effect before and after Topic 606
Distribution Made to Limited Partner [Line Items]
Cumulative effect adjustment, net of tax, to partner's capital			$ 35		$ 35

Cash and Securities Segregate45

Cash and Securities Segregated Under Federal Regulations and Other Requirements (Details) - USD ($) $ in Billions	Mar. 31, 2018	Dec. 31, 2017
Brokers and Dealers [Abstract]
United States Treasury Bills in special reserve bank custody account for exclusive benefit of brokerage customers of SCB LLC	$ 1	$ 0.8

Investments (Summary of Investm

Investments (Summary of Investments) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Summary of Investment Holdings [Line Items]
Investments owned	$ 405,381	$ 443,589
Long-term incentive compensation obligations	56,400	66,034
Seed capital
Summary of Investment Holdings [Line Items]
Investments owned	563,300	523,200
U.S. Treasury Bills
Summary of Investment Holdings [Line Items]
Investments owned	52,685	52,609
Equity securities | Long-term incentive compensation-related
Summary of Investment Holdings [Line Items]
Investments owned	42,022	51,758
Equity securities | Seed capital
Summary of Investment Holdings [Line Items]
Investments owned	137,033	160,672
Equity securities | Other
Summary of Investment Holdings [Line Items]
Investments owned	74,177	81,154
Exchange-traded options
Summary of Investment Holdings [Line Items]
Investments owned	5,395	4,981
Investments in limited partnership hedge funds | Long-term incentive compensation-related
Summary of Investment Holdings [Line Items]
Investments owned	14,378	14,276
Investments in limited partnership hedge funds | Seed capital
Summary of Investment Holdings [Line Items]
Investments owned	24,734	22,923
Private equity (seed capital)
Summary of Investment Holdings [Line Items]
Investments owned	38,011	38,186
Time deposits
Summary of Investment Holdings [Line Items]
Investments owned	5,160	5,138
Other
Summary of Investment Holdings [Line Items]
Investments owned	$ 11,786	$ 11,892

Investments (Gains (Losses) Rel

Investments (Gains (Losses) Related to Equity Securities) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Investments, Debt and Equity Securities [Abstract]
Net (losses) gains recognized during the period	$ (1,823)	$ 14,189
Less: net gains recognized during the period on equity securities sold during the period	1,282	1,408
Unrealized (losses) gains recognized during the period on equity securities held	$ (3,105)	$ 12,781

Derivative Instruments (Notiona

Derivative Instruments (Notional Value and Fair Value of Derivative Instruments) (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Notional Value	$ 600,709	$ 475,976
Asset Derivatives	13,565	11,619
Liability Derivatives	13,106	14,323
Exchange-traded futures
Derivative [Line Items]
Notional Value	178,462	163,458
Asset Derivatives	1,517	948
Liability Derivatives	1,240	2,540
Currency forwards
Derivative [Line Items]
Notional Value	157,448	126,503
Asset Derivatives	8,286	8,306
Liability Derivatives	8,347	8,058
Interest rate swaps
Derivative [Line Items]
Notional Value	50,403	43,309
Asset Derivatives	843	951
Liability Derivatives	659	870
Credit default swaps
Derivative [Line Items]
Notional Value	78,741	74,600
Asset Derivatives	1,403	1,247
Liability Derivatives	2,410	2,465
Total return swaps
Derivative [Line Items]
Notional Value	135,655	68,106
Asset Derivatives	1,516	167
Liability Derivatives	$ 450	$ 390

Derivative Instruments (Gains a

Derivative Instruments (Gains and Losses for Derivative Instruments Recognized in Investment Gains (Losses)) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Derivative [Line Items]
Net gains (losses) on derivative instruments	$ 2,367	$ (9,492)
Exchange-traded futures
Derivative [Line Items]
Net gains (losses) on derivative instruments	825	(5,532)
Currency forwards
Derivative [Line Items]
Net gains (losses) on derivative instruments	17	(1,062)
Interest rate swaps
Derivative [Line Items]
Net gains (losses) on derivative instruments	274	(97)
Credit default swaps
Derivative [Line Items]
Net gains (losses) on derivative instruments	74	(672)
Total return swaps
Derivative [Line Items]
Net gains (losses) on derivative instruments	$ 1,177	$ (2,129)

Derivative Instruments (Details

Derivative Instruments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Derivative [Line Items]
Cash collateral payable to trade counterparties	$ 2,400		$ 500
Cash collateral received	4,700		8,800
Loss on equity options activity	4,200	$ 3,700
Exchange-traded options | Long
Derivative [Line Items]
Cash collateral payable to trade counterparties	0		0
Long exchange-traded equity options	5,400		5,000
Exchange-traded options | Short
Derivative [Line Items]
Cash collateral received	0		0
Short exchange-traded equity options, included in securities sold not yet purchased	$ 14,000		$ 13,600

Offsetting Assets and Liabili51

Offsetting Assets and Liabilities (Offsetting Assets) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivative Asset [Abstract]
Cash Collateral Received	$ (2,400)	$ (500)
Securities borrowed
Securities Borrowed [Abstract]
Gross Amounts of Recognized Assets	48,302	85,371
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	48,302	85,371
Financial Instruments	(46,858)	(82,353)
Cash Collateral Received	0	0
Net Amount	1,444	3,018
Derivatives
Derivative Asset [Abstract]
Gross Amounts of Recognized Assets	13,565	11,619
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	13,565	11,619
Financial Instruments	0	0
Cash Collateral Received	(2,364)	(519)
Net Amount	11,201	11,100
Exchange-traded options | Long
Derivative Asset [Abstract]
Gross Amounts of Recognized Assets	5,395	4,981
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	5,395	4,981
Financial Instruments	0	0
Cash Collateral Received	0	0
Net Amount	$ 5,395	$ 4,981

Offsetting Assets and Liabili52

Offsetting Assets and Liabilities (Offsetting Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivative Liability [Abstract]
Cash Collateral Pledged	$ (4,700)	$ (8,800)
Securities loaned
Securities Loaned [Abstract]
Gross Amounts of Recognized Liabilities	20,500	37,960
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	20,500	37,960
Financial Instruments	(20,500)	(37,922)
Cash Collateral Pledged	0	0
Net Amount	0	38
Derivatives
Derivative Liability [Abstract]
Gross Amounts of Recognized Liabilities	13,106	14,323
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	13,106	14,323
Financial Instruments	0	0
Cash Collateral Pledged	(4,724)	(8,794)
Net Amount	8,382	5,529
Exchange-traded options | Short
Derivative Liability [Abstract]
Gross Amounts of Recognized Liabilities	13,966	13,585
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	13,966	13,585
Financial Instruments	0	0
Cash Collateral Pledged	0	0
Net Amount	$ 13,966	$ 13,585

Fair Value (Valuation of Financ

Fair Value (Valuation of Financial Instruments) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, NAV Expedient	$ 37,100
Other	56,058	$ 54,229
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money markets	48,942	62,071
Securities segregated (U.S. Treasury Bills)	1,024,529	816,350
Derivatives	13,565	11,619
Private equity	38,011	38,186
Investments, NAV Expedient	37,470	37,326
Total investments measured at fair value and other measurements	405,381	443,589
Total assets measured at fair value and other measurements	1,492,417	1,333,629
Securities sold not yet purchased
Short equities – corporate	13,567	16,376
Short exchange-traded options	13,966	13,585
Derivatives	13,106	14,323
Contingent payment arrangements	10,908	10,855
Total liabilities measured at fair value	51,547	55,139
Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money markets	48,942	62,071
Securities segregated (U.S. Treasury Bills)	0	0
Derivatives	1,517	948
Private equity	0	0
Total investments	242,564	281,736
Total assets measured at fair value	293,023	344,755
Securities sold not yet purchased
Short equities – corporate	13,567	16,376
Short exchange-traded options	13,966	13,585
Derivatives	1,240	2,540
Contingent payment arrangements	0	0
Total liabilities measured at fair value	28,773	32,501
Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money markets	0	0
Securities segregated (U.S. Treasury Bills)	1,024,529	816,350
Derivatives	12,048	10,671
Private equity	0	0
Total investments	68,218	69,227
Total assets measured at fair value	1,104,795	896,248
Securities sold not yet purchased
Short equities – corporate	0	0
Short exchange-traded options	0	0
Derivatives	11,866	11,783
Contingent payment arrangements	0	0
Total liabilities measured at fair value	11,866	11,783
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Money markets	0	0
Securities segregated (U.S. Treasury Bills)	0	0
Derivatives	0	0
Private equity	954	954
Total investments	1,071	1,071
Total assets measured at fair value	1,071	1,071
Securities sold not yet purchased
Short equities – corporate	0	0
Short exchange-traded options	0	0
Derivatives	0	0
Contingent payment arrangements	10,908	10,855
Total liabilities measured at fair value	10,908	10,855
U.S. Treasury Bills | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	52,685	52,609
U.S. Treasury Bills | Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	0	0
U.S. Treasury Bills | Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	52,685	52,609
U.S. Treasury Bills | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	0	0
Equity securities | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	253,232	293,584
Investments, NAV Expedient	413	94
Equity securities | Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	237,169	276,755
Equity securities | Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	15,533	16,618
Equity securities | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	117	117
Private equity | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, NAV Expedient	37,057	37,232
Other investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other	11,786	11,892
Other investments | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other	11,786	11,892
Time deposits
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other	5,160	5,138
Time deposits | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other	5,160	5,138
Long | Exchange-traded options | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	5,395	4,981
Long | Exchange-traded options | Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	5,395	4,981
Long | Exchange-traded options | Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	0	0
Long | Exchange-traded options | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Trading securities	0	0
Limited partnership hedge funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other	39,112	37,199
Limited partnership hedge funds | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other	$ 39,112	$ 37,199

Fair Value (Details)

Fair Value (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investments, NAV Expedient	$ 37,100,000
Other investments	56,058,000	$ 54,229,000
Assets measured at fair value for impairment on a nonrecurring basis	0	0
Liabilities measured at fair value for impairment on a nonrecurring basis	0	0
Private Equity Investment Energy Fund
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investments	1,000,000	1,000,000
Recurring
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Investments, NAV Expedient	37,470,000	37,326,000
Contingent payment arrangements	10,908,000	10,855,000
Recurring | Contingent Payment Arrangements
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Contingent payment arrangements	$ 10,900,000	10,900,000
Minimum | Contingent Payment Arrangements
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Revenue growth rate	31.00%
Discount rate	1.40%
Maximum | Contingent Payment Arrangements
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Discount rate	2.30%
Private equity
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Unfunded commitment	$ 0
Start-up company
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Other investments	4,600,000	4,600,000
Equity method investee
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Other investments	4,000,000	4,100,000
Broker dealer exchange memberships
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Other investments	$ 3,200,000	$ 3,200,000

Fair Value (Change in Carrying

Fair Value (Change in Carrying Value of Level 3 Financial Instruments) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Fair value measurement Level 3 reconciliation [Abstract]
Balance as of beginning of period	$ 1,071	$ 5,023
Purchases	0	0
Sales	0	0
Realized gains (losses), net	0	0
Unrealized gains (losses), net	0	3
Balance as of end of period	$ 1,071	$ 5,026

Fair Value (Change in Carryin56

Fair Value (Change in Carrying Value Associated with Contingent Payment Arrangements Level 3 Instruments) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Fair Value, Liabilities Measurement Level 3 reconciliation
Balance as of beginning of period	$ 10,855	$ 17,589
Accretion	53	178
Payments	0	(590)
Balance as of end of period	$ 10,908	$ 17,177

Consolidated Company-Sponsore57

Consolidated Company-Sponsored Investment Funds (Summary of Balance Sheet Amounts) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	$ 1,220,555	$ 998,448	$ 1,064,877	$ 994,510
Other assets	236,727	211,893
Total assets	10,561,530	9,295,167
Liabilities	5,507,089	4,630,276
Redeemable non-controlling interest	996,966	601,587
Partners' capital attributable to AB Unitholders	4,055,845	4,061,740
Non-redeemable non-controlling interests in consolidated entities	1,630	1,564
Total liabilities, redeemable non-controlling interest and capital	10,561,530	9,295,167
Company-sponsored investment funds
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	580,721	326,518
Investments	1,956,470	1,246,283
Other assets	44,492	35,397
Liabilities	1,222,874	698,101
Redeemable non-controlling interest	991,602	596,223
Non-redeemable non-controlling interests in consolidated entities	710	757
Reportable entities | Company-sponsored investment funds
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	580,721	326,518
Investments	1,956,470	1,246,283
Other assets	44,492	35,397
Total assets	2,581,683	1,608,198
Liabilities	1,222,874	698,101
Redeemable non-controlling interest	991,602	596,223
Partners' capital attributable to AB Unitholders	366,497	313,117
Non-redeemable non-controlling interests in consolidated entities	710	757
Total liabilities, redeemable non-controlling interest and capital	2,581,683	1,608,198
Reportable entities | VIEs
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	580,239	326,158
Investments	1,826,576	1,189,835
Other assets	40,242	33,931
Total assets	2,447,057	1,549,924
Liabilities	1,218,612	695,997
Redeemable non-controlling interest	981,961	596,241
Partners' capital attributable to AB Unitholders	245,774	256,929
Non-redeemable non-controlling interests in consolidated entities	710	757
Total liabilities, redeemable non-controlling interest and capital	2,447,057	1,549,924
Reportable entities | VOEs
Condensed Balance Sheet Statements, Captions [Line Items]
Cash and cash equivalents	482	360
Investments	129,894	56,448
Other assets	4,250	1,466
Total assets	134,626	58,274
Liabilities	4,262	2,104
Redeemable non-controlling interest	9,641	(18)
Partners' capital attributable to AB Unitholders	120,723	56,188
Non-redeemable non-controlling interests in consolidated entities	0	0
Total liabilities, redeemable non-controlling interest and capital	$ 134,626	$ 58,274

Consolidated Company-Sponsore58

Consolidated Company-Sponsored Investment Funds (Fair Value) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, NAV Expedient	$ 37,100
Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives	13,565	$ 11,619
Investments, NAV Expedient	37,470	37,326
Short equities	13,567	16,376
Derivatives	13,106	14,323
Total liabilities measured at fair value	51,547	55,139
Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	242,564	281,736
Derivatives	1,517	948
Total assets measured at fair value	293,023	344,755
Short equities	13,567	16,376
Derivatives	1,240	2,540
Total liabilities measured at fair value	28,773	32,501
Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	68,218	69,227
Derivatives	12,048	10,671
Total assets measured at fair value	1,104,795	896,248
Short equities	0	0
Derivatives	11,866	11,783
Total liabilities measured at fair value	11,866	11,783
Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	1,071	1,071
Derivatives	0	0
Total assets measured at fair value	1,071	1,071
Short equities	0	0
Derivatives	0	0
Total liabilities measured at fair value	10,908	10,855
Company-sponsored investment funds | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, NAV Expedient	0	10
Total assets measured at fair value	1,988,114	1,277,219
Total liabilities measured at fair value	1,207,700	692,130
Company-sponsored investment funds | Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	1,690,675	1,059,616
Total liabilities measured at fair value	1,189,740	669,691
Company-sponsored investment funds | Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	291,538	215,329
Total liabilities measured at fair value	17,960	22,439
Company-sponsored investment funds | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets measured at fair value	5,901	2,264
Total liabilities measured at fair value	0	0
VIEs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives	31,006	30,636
Derivatives	18,400	22,241
VIEs | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	1,826,576	1,189,835
Derivatives	31,006	30,636
Investments, NAV Expedient	0	10
Derivatives	18,400	22,241
VIEs | Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	1,612,691	1,053,824
Derivatives	769	252
Derivatives	1,027	421
VIEs | Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	208,118	133,796
Derivatives	30,237	30,384
Derivatives	17,373	21,820
VIEs | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	5,767	2,205
Derivatives	0	0
Derivatives	0	0
VIEs | Short | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short equities	1,188,624	669,258
VIEs | Short | Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short equities	1,188,624	669,258
VIEs | Short | Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short equities	0	0
VIEs | Short | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Short equities	0	0
VOEs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives	638	300
Derivatives	676	631
VOEs | Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	129,894	56,448
Derivatives	638	300
Investments, NAV Expedient		0
Derivatives	676	631
VOEs | Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	77,172	5,491
Derivatives	43	49
Derivatives	89	12
VOEs | Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	52,588	50,898
Derivatives	595	251
Derivatives	587	619
VOEs | Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments	134	59
Derivatives	0	0
Derivatives	$ 0	$ 0

Consolidated Company-Sponsore59

Consolidated Company-Sponsored Investment Funds (Change in Carrying Value Associated with Level 3 Financial Instruments) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Fair value measurement Level 3 reconciliation [Abstract]
Balance as of beginning of period	$ 1,071	$ 5,023
Purchases	0	0
Sales	0	0
Realized gains (losses), net	0	0
Unrealized (losses) gains, net	0	3
Balance as of end of period	1,071	5,026
Company-sponsored investment funds
Fair value measurement Level 3 reconciliation [Abstract]
Balance as of beginning of period	2,264	5,741
Transfers in (out)	(13)	749
Purchases	4,034	4,577
Sales	(333)	(1,073)
Realized gains (losses), net	5	(12)
Unrealized (losses) gains, net	(58)	271
Accrued discounts	2	20
Balance as of end of period	$ 5,901	$ 10,273

Consolidated Company-Sponsore60

Consolidated Company-Sponsored Investment Funds (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Derivative [Line Items]
Gain (loss) on derivative instruments	$ 2,367	$ (9,492)
Cash collateral payable to trade counterparties	2,400		$ 500
Cash collateral received	4,700		8,800
Net assets of investment products that are non-consolidated VIEs	83,900,000
Maximum risk of loss in investment in VIEs	8,000
VIEs
Derivative [Line Items]
Futures, forwards and swaps held	12,600		8,400
Gain (loss) on derivative instruments	(14,900)	7,200
Cash collateral payable to trade counterparties	2,271		194
Cash collateral received	1,400		2,900
VOEs
Derivative [Line Items]
Futures, forwards and swaps held	38		300
Gain (loss) on derivative instruments	(500)	$ (400)
Cash collateral payable to trade counterparties	47		37
Cash collateral received	$ 300		$ 200

Consolidated Company-Sponsore61

Consolidated Company-Sponsored Investment Funds (Offsetting of Derivative Assets and Liabilities) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Derivative Asset [Abstract]
Cash Collateral Received	$ (2,400)	$ (500)
VIEs
Derivative Asset [Abstract]
Gross Amounts of Recognized Assets	31,006	30,636
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	31,006	30,636
Financial Instruments	0	0
Cash Collateral Received	(2,271)	(194)
Net Amount	28,735	30,442
Derivative Liability [Abstract]
Gross Amounts of Recognized Liabilities	18,400	22,241
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	18,400	22,241
Financial Instruments	0	0
Cash Collateral Pledged	(1,372)	(2,884)
Net Amount	17,028	19,357
VOEs
Derivative Asset [Abstract]
Gross Amounts of Recognized Assets	638	300
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Assets Presented in the Statement of Financial Position	638	300
Financial Instruments	0	0
Cash Collateral Received	(47)	(37)
Net Amount	591	263
Derivative Liability [Abstract]
Gross Amounts of Recognized Liabilities	676	631
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	676	631
Financial Instruments	0	0
Cash Collateral Pledged	(253)	(228)
Net Amount	$ 423	$ 403

Units Outstanding (Details)

Units Outstanding (Details) - shares	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Units Outstanding
Outstanding as of December 31, 2017 (in units)	268,659,333
Options exercised (in units)	235,105	300,000
Units issued (in units)	949,185
Units retired (in units)	(3,686)
Balance as of March 31, 2018 (in units)	269,839,937
Limited Partners' Capital Account [Line Items]
Units purchased and retired (in units)	3,686
AB Units
Units Outstanding
Units retired (in units)	(1,150)
Limited Partners' Capital Account [Line Items]
Units purchased and retired (in units)	1,150

Debt (Details)

Debt (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017
Short-term Debt [Line Items]
Short-term debt outstanding	$ 489,830,000	$ 565,745,000
Commercial Paper
Short-term Debt [Line Items]
Short-term debt outstanding	$ 489,800,000	$ 491,800,000
Weighted average interest rate	2.10%	1.60%
Average daily borrowings	$ 480,500,000	$ 482,200,000
Weighted average interest rates on average daily borrowings	1.70%	1.20%
Revolving Credit Facility | Line of Credit
Short-term Debt [Line Items]
Line of credit facility, maximum borrowing capacity	$ 200,000,000
Debt instrument term	364 days
Amount outstanding	$ 0	$ 75,000,000
Interest rate		2.40%
Average daily borrowings	$ 21,900,000	$ 21,400,000
Weighted average interest rates	2.40%	2.00%

Changes in Capital (Details)

Changes in Capital (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Jan. 01, 2018
Changes in capital [Roll Forward]
Partners' capital, beginning balance	$ 4,061,740
Partners' capital attributable to non-controlling interest, beginning balance	1,564
Partner's capital including portion attributable to non-controlling interest, beginning balance	4,063,304
Comprehensive income:
Net income	206,846	$ 156,255
Other comprehensive income, net of tax:
Foreign currency translation adjustments	9,921	8,867
Changes in employee benefit related items	170	189
Comprehensive income attributable to AB Unitholders	194,270	148,899
Distributions to General Partner and unitholders	(247,773)	(198,040)
Partners' capital, ending balance	4,055,845
Partners' capital attributable to non-controlling interest, ending balance	1,630
Partner's capital including portion attributable to non-controlling interest, ending balance	4,057,475
Partners’ Capital Attributable to AB Unitholders
Changes in capital [Roll Forward]
Partners' capital, beginning balance	4,061,740	4,032,017
Comprehensive income:
Net income	184,196	139,937
Other comprehensive income, net of tax:
Unrealized gains (losses) on investments	0	(18)
Foreign currency translation adjustments	9,904	8,791
Changes in employee benefit related items	170	189
Comprehensive income attributable to AB Unitholders	194,270	148,899
Distributions to General Partner and unitholders	(247,773)	(198,040)
Compensation-related transactions	14,334	(18,673)
Capital contributions to affiliates	(1,677)	(81)
Distributions to non-controlling interests of our consolidated venture capital fund	0	0
Partners' capital, ending balance	4,055,845	3,964,122
Non-Controlling Interests In Consolidated Entities
Changes in capital [Roll Forward]
Partners' capital attributable to non-controlling interest, beginning balance	1,564	36,172
Comprehensive income:
Net income attributable to noncontrolling interest	54	1,632
Other comprehensive income, net of tax:
Unrealized gains (losses) on investments	0	0
Foreign currency translation adjustments	17	76
Changes in employee benefit related items	0	0
Comprehensive income attributable to non-controlling interest	71	1,708
Distributions to General Partner and unitholders	0	0
Compensation-related transactions	0	0
Capital contributions to affiliates	0	0
Distributions to non-controlling interests of our consolidated venture capital fund	(5)	(3,137)
Partners' capital attributable to non-controlling interest, ending balance	1,630	34,743
Total Capital
Changes in capital [Roll Forward]
Partner's capital including portion attributable to non-controlling interest, beginning balance	4,063,304	4,068,189
Comprehensive income:
Net income	184,250	141,569
Other comprehensive income, net of tax:
Unrealized gains (losses) on investments	0	(18)
Foreign currency translation adjustments	9,921	8,867
Changes in employee benefit related items	170	189
Comprehensive income	194,341	150,607
Distributions to General Partner and unitholders	(247,773)	(198,040)
Compensation-related transactions	14,334	(18,673)
Capital contributions to affiliates	(1,677)	(81)
Distributions to non-controlling interests of our consolidated venture capital fund	(5)	(3,137)
Partner's capital including portion attributable to non-controlling interest, ending balance	4,057,475	$ 3,998,865
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Other comprehensive income, net of tax:
Impact of adoption of revenue recognition standard ASC 606	35,000		$ 35,000
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09 | Partners’ Capital Attributable to AB Unitholders
Other comprehensive income, net of tax:
Impact of adoption of revenue recognition standard ASC 606	34,951
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09 | Non-Controlling Interests In Consolidated Entities
Other comprehensive income, net of tax:
Impact of adoption of revenue recognition standard ASC 606	0
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09 | Total Capital
Other comprehensive income, net of tax:
Impact of adoption of revenue recognition standard ASC 606	$ 34,951

Non-controlling Interests (Deta

Non-controlling Interests (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Noncontrolling Interest [Line Items]
Non-redeemable non-controlling interests	$ 56	$ 1,632
Total non-controlling interest in net income	22,650	16,318
Non-redeemable non-controlling interest	1,630		$ 1,564
Redeemable non-controlling interest	996,966		601,587
CPH acquisition
Noncontrolling Interest [Line Items]
Non-redeemable non-controlling interest	920		807
Redeemable non-controlling interest	5,364		5,364
Other
Noncontrolling Interest [Line Items]
Non-redeemable non-controlling interests	98	147
Company-sponsored investment funds
Noncontrolling Interest [Line Items]
Non-redeemable non-controlling interests	(42)	1,485
Redeemable non-controlling interests	22,594	$ 14,686
Non-redeemable non-controlling interest	710		757
Redeemable non-controlling interest	$ 991,602		$ 596,223