TD Ameritrade Holding 10-K 22 Nov 13 2013 FY Annual report Financial data

Document_and_Entity_Informatio

Document and Entity Information (USD $)	12 Months Ended
In Billions, except Share data, unless otherwise specified	Sep. 30, 2013	Nov. 08, 2013	Mar. 28, 2013
Document And Entity Information [Abstract]	'	'	'
Document Type	'10-K	'	'
Amendment Flag	'false	'	'
Document Period End Date	30-Sep-13	'	'
Document Fiscal Year Focus	'2013	'	'
Document Fiscal Period Focus	'FY	'	'
Trading Symbol	'AMTD	'	'
Entity Registrant Name	'TD AMERITRADE HOLDING CORP	'	'
Entity Central Index Key	'0001173431	'	'
Current Fiscal Year End Date	'--09-30	'	'
Entity Well-known Seasoned Issuer	'Yes	'	'
Entity Current Reporting Status	'Yes	'	'
Entity Voluntary Filers	'No	'	'
Entity Filer Category	'Large Accelerated Filer	'	'
Entity Common Stock, Shares Outstanding	'	550,487,088	'
Entity Public Float	'	'	$5.10

CONSOLIDATED_BALANCE_SHEETS

CONSOLIDATED BALANCE SHEETS (USD $)	Sep. 30, 2013	Sep. 30, 2012
In Millions, unless otherwise specified
ASSETS	'	'
Cash and cash equivalents	$1,062	$915
Short-term investments available-for-sale, at fair value	4	154
Cash and investments segregated and on deposit for regulatory purposes	5,894	4,030
Receivable from brokers, dealers and clearing organizations	1,348	1,110
Receivable from clients, net	8,984	8,647
Receivable from affiliates	117	85
Other receivables, net	137	118
Securities owned, at fair value	323	343
Investments available-for-sale, at fair value	13	70
Property and equipment at cost, net	497	444
Goodwill	2,467	2,467
Acquired intangible assets, net	841	932
Deferred income taxes	1	2
Other assets	148	196
Total assets	21,836	19,513
Liabilities:	'	'
Payable to brokers, dealers and clearing organizations	1,973	1,992
Payable to clients	13,183	10,728
Accounts payable and accrued liabilities	582	632
Payable to affiliates	4	4
Deferred revenue	14	28
Long-term debt	1,052	1,345
Capitalized lease obligations	'	5
Deferred income taxes	352	354
Total liabilities	17,160	15,088
Stockholders' equity:	'	'
Preferred stock, $0.01 par value, 100 million shares authorized; none issued	'	'
Common stock, $0.01 par value, one billion shares authorized; 631 million shares issued; 2013 - 550 million shares outstanding; 2012 - 545 million shares outstanding	6	6
Additional paid-in capital	1,592	1,587
Retained earnings	4,304	4,100
Treasury stock, common, at cost: 2013 - 81 million shares; 2012 - 86 million shares	-1,226	-1,286
Net unrealized gain on investments available-for-sale	'	18
Total stockholders' equity	4,676	4,425
Total liabilities and stockholders' equity	$21,836	$19,513

CONSOLIDATED_BALANCE_SHEETS_Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)	Sep. 30, 2013	Sep. 30, 2012
Statement Of Financial Position [Abstract]	'	'
Preferred stock, par value	$0.01	$0.01
Preferred stock, shares authorized	100,000,000	100,000,000
Preferred stock, shares issued	0	0
Common stock, par value	$0.01	$0.01
Common stock, shares authorized	1,000,000,000	1,000,000,000
Common stock, shares issued	631,000,000	631,000,000
Common stock, shares outstanding	550,000,000	545,000,000
Treasury stock, shares	81,000,000	86,000,000

CONSOLIDATED_STATEMENTS_OF_INC

CONSOLIDATED STATEMENTS OF INCOME (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Transaction-based revenues:	'	'	'
Commissions and transaction fees	$1,171	$1,087	$1,228
Asset-based revenues:	'	'	'
Interest revenue	476	456	497
Brokerage interest expense	-7	-6	-5
Net interest revenue	469	450	492
Insured deposit account fees	804	828	763
Investment product fees	250	196	166
Total asset-based revenues	1,523	1,474	1,421
Other revenues	70	80	114
Net revenues	2,764	2,641	2,763
Operating expenses:	'	'	'
Employee compensation and benefits	692	690	675
Clearing and execution costs	109	89	100
Communications	113	111	107
Occupancy and equipment costs	160	150	142
Depreciation and amortization	86	72	67
Amortization of acquired intangible assets	91	92	97
Professional services	145	168	170
Advertising	239	248	253
Other	73	87	104
Total operating expenses	1,708	1,707	1,715
Operating income	1,056	934	1,048
Other expense (income):	'	'	'
Interest on borrowings	25	28	32
Loss on debt refinancing	'	'	1
Gain on investments, net [2013 includes ($49) accumulated other comprehensive income reclassifications for net unrealized gains on available-for-sale investments]	-57	'	-2
Total other expense (income)	-32	28	31
Pre-tax income	1,088	906	1,017
Provision for income taxes [2013 includes $18 from reclassification items]	413	320	379
Net income	$675	$586	$638
Earnings per share - basic	$1.23	$1.07	$1.12
Earnings per share - diluted	$1.22	$1.06	$1.11
Weighted average shares outstanding - basic	549	548	570
Weighted average shares outstanding - diluted	554	554	576
Dividends declared per share	$0.86	$0.24	$0.20

CONSOLIDATED_STATEMENTS_OF_INC1

CONSOLIDATED STATEMENTS OF INCOME (Parenthetical) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013
Provision for income taxes	$413
Reclassification out of Accumulated Other Comprehensive Income [Member]	'
Accumulated other comprehensive income, reclassifications	49
Provision for income taxes	$18

CONSOLIDATED_STATEMENTS_OF_COM

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (USD $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Statement Of Comprehensive Income Loss [Abstract]	'	'	'
Net income	$675	$586	$638
Other comprehensive income (loss):	'	'	'
Net unrealized gain	21	28	'
Reclassification adjustment for net realized gain included in net income	-52	'	'
Reclassification of impairment charge	3	'	'
Total other comprehensive income (loss), before tax	-28	28	'
Income tax effects:	'	'	'
Net unrealized gain	-8	-10	'
Reclassification adjustment for net realized gain included in net income	19	'	'
Reclassification of impairment charge	-1	'	'
Total income tax effects	10	-10	'
Total other comprehensive income (loss), net of tax	-18	18	'
Comprehensive income	$657	$604	$638

CONSOLIDATED_STATEMENTS_OF_STO

CONSOLIDATED STATEMENTS OF STOCKHOLDERS EQUITY (USD $)	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Net Unrealized Gain (Loss) on Investments Available-For-Sale [Member]
In Millions, unless otherwise specified
Balance at Sep. 30, 2010	$3,772	$6	$1,391	$3,122	($747)	'
Balance, shares at Sep. 30, 2010	576	'	'	'	'	'
Shareholders Equity [Line Items]	'	'	'	'	'	'
Net income	638	'	'	638	'	'
Other comprehensive income, net of tax	'	'	'	'	'	'
Payment of cash dividends	-114	'	'	-114	'	'
Repurchases of common stock	-349	'	'	'	-349	'
Repurchases of common stock (in Shares)	-21	'	'	'	'	'
Settlement of structured stock repurchase	'	'	50	'	-50	'
Settlement of structured stock repurchase (in Shares)	-3	'	'	'	'	'
Return of prepayment on structured stock repurchase	119	'	119	'	'	'
Common stock issued for stock-based compensation, including tax effects	13	'	-13	'	26	'
Common stock issued for stock-based compensation, including tax effects, shares	2	'	'	'	'	'
Stock-based compensation expense	35	'	35	'	'	'
Other	2	'	2	'	'	'
Balance at Sep. 30, 2011	4,116	6	1,584	3,646	-1,120	'
Balance, shares at Sep. 30, 2011	554	'	'	'	'	'
Shareholders Equity [Line Items]	'	'	'	'	'	'
Net income	586	'	'	586	'	'
Other comprehensive income, net of tax	18	'	'	'	'	18
Payment of cash dividends	-132	'	'	-132	'	'
Repurchases of common stock	-208	'	'	'	-208	'
Repurchases of common stock (in Shares)	-12	'	'	'	'	'
Common stock issued for stock-based compensation, including tax effects	4	'	-38	'	42	'
Common stock issued for stock-based compensation, including tax effects, shares	3	'	'	'	'	'
Stock-based compensation expense	41	'	41	'	'	'
Balance at Sep. 30, 2012	4,425	6	1,587	4,100	-1,286	18
Balance, shares at Sep. 30, 2012	545	'	'	'	'	'
Shareholders Equity [Line Items]	'	'	'	'	'	'
Net income	675	'	'	675	'	'
Other comprehensive income, net of tax	-18	'	'	'	'	-18
Payment of cash dividends	-471	'	'	-471	'	'
Repurchases of common stock	-5	'	'	'	-5	'
Common stock issued for stock-based compensation, including tax effects	41	'	-24	'	65	'
Common stock issued for stock-based compensation, including tax effects, shares	5	'	'	'	'	'
Stock-based compensation expense	29	'	29	'	'	'
Balance at Sep. 30, 2013	$4,676	$6	$1,592	$4,304	($1,226)	'
Balance, shares at Sep. 30, 2013	550	'	'	'	'	'

CONSOLIDATED_STATEMENTS_OF_CAS

CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Cash flows from operating activities:	'	'	'
Net income	$675	$586	$638
Adjustments to reconcile net income to net cash provided by operating activities:	'	'	'
Depreciation and amortization	86	72	67
Amortization of acquired intangible assets	91	92	97
Deferred income taxes	10	5	2
Gain on investments, net	-57	'	-2
Loss on disposal of property	5	10	17
Loss on debt refinancing	'	'	1
Stock-based compensation	29	41	35
Excess tax benefits on stock-based compensation	-24	-9	-10
Other, net	-3	-2	'
Changes in operating assets and liabilities:	'	'	'
Cash and investments segregated and on deposit for regulatory purposes	-1,864	-1,511	-1,525
Receivable from brokers, dealers and clearing organizations	-238	-275	373
Receivable from clients, net	-337	-588	-668
Receivable from/payable to affiliates, net	-32	7	1
Other receivables, net	-19	-3	-44
Securities owned, at fair value	20	104	-229
Other assets	4	'	-6
Payable to brokers, dealers and clearing organizations	-19	282	-225
Payable to clients	2,455	1,749	2,169
Accounts payable and accrued liabilities	-29	46	120
Deferred revenue	-14	-14	-21
Net cash provided by operating activities	739	592	790
Cash flows from investing activities:	'	'	'
Purchase of property and equipment	-144	-186	-153
Cash received in sale of business	'	'	5
Cash transferred in disposal of subsidiary	'	'	-3
Purchase of short-term investments	-4	-155	-4
Proceeds from sale and maturity of short-term investments	154	4	4
Proceeds from sale of investments	88	2	3
Purchase of investments	'	-44	-5
Other, net	2	2	1
Net cash provided by (used in) investing activities	96	-377	-152
Cash flows from financing activities:	'	'	'
Payment of debt issuance costs	'	'	-2
Principal payments on long-term debt	-250	'	-4
Proceeds from notes payable	275	'	'
Principal payments on notes payable	-275	'	'
Principal payments on capital lease obligations	-5	-6	-10
Proceeds from exercise of stock options	19	5	3
Purchase of treasury stock	-5	-208	-349
Return of prepayment on structured stock repurchase	'	'	119
Payment of cash dividends	-471	-132	-114
Excess tax benefits on stock-based compensation	24	9	10
Net cash provided by (used in) financing activities	-688	-332	-347
Net increase (decrease) in cash and cash equivalents	147	-117	291
Cash and cash equivalents at beginning of year	915	1,032	741
Cash and cash equivalents at end of year	1,062	915	1,032
Supplemental cash flow information:	'	'	'
Interest paid	32	34	43
Income taxes paid	$379	$313	$321

Nature_of_Operations_and_Summa

Nature of Operations and Summary of Significant Accounting Policies	12 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
Nature of Operations and Summary of Significant Accounting Policies	'
	1	Nature of Operations and Summary of Significant Accounting Policies
	Basis of Presentation — The consolidated financial statements include the accounts of TD Ameritrade Holding Corporation, a Delaware corporation, and its wholly-owned subsidiaries (collectively, the “Company”). Intercompany balances and transactions have been eliminated.
	Nature of Operations — The Company provides securities brokerage services, including trade execution, clearing services and margin lending, through its broker-dealer subsidiaries. The Company provides trustee, custodial and other trust-related services to retirement plans and other custodial accounts through its state-chartered trust company subsidiary. The Company’s education subsidiary provides a comprehensive suite of investor education products and services. The Company also provides cash sweep and deposit account products through third-party relationships.
	The Company’s broker-dealer subsidiaries are subject to regulation by the Securities and Exchange Commission (“SEC”), the Financial Industry Regulatory Authority (“FINRA”), the Commodity Futures Trading Commission (“CFTC”), the National Futures Association (“NFA”) and the various exchanges in which they maintain membership. Dividends from the Company’s broker-dealer and trust company subsidiaries are a source of liquidity for the holding company. Requirements of the SEC, FINRA and CFTC relating to liquidity, net capital standards and the use of client funds and securities may limit funds available for the payment of dividends from the broker-dealer subsidiaries to the holding company. State regulatory requirements may limit funds available for the payment of dividends from the trust company subsidiary to the holding company.
	Use of Estimates — The preparation of consolidated financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amount of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
	Cash and Cash Equivalents — The Company considers temporary, highly-liquid investments with an original maturity of three months or less to be cash equivalents, except for amounts required to be segregated for regulatory purposes.
	Cash and Investments Segregated and on Deposit for Regulatory Purposes — Cash and investments segregated and on deposit for regulatory purposes consists primarily of qualified deposits in special reserve bank accounts for the exclusive benefit of clients under Rule 15c3-3 of the Securities Exchange Act of 1934 (the “Exchange Act”) and other regulations. Funds can be held in cash, reverse repurchase agreements, U.S. Treasury securities and other qualified securities. Reverse repurchase agreements (securities purchased under agreements to resell) are treated as collateralized financing transactions and are carried at amounts at which the securities will subsequently be resold, plus accrued interest. The Company’s reverse repurchase agreements are collateralized by U.S. Treasury securities and generally have a maturity of seven days. Cash and investments segregated and on deposit for regulatory purposes also includes amounts that have been segregated or secured for the benefit of futures clients according to the regulations of the CFTC governing futures commission merchants.
	Securities Borrowed and Securities Loaned — Securities borrowed and securities loaned transactions are recorded at the amount of cash collateral advanced or received. Securities borrowed transactions require the Company to provide the counterparty with collateral in the form of cash. The Company receives collateral in the form of cash for securities loaned transactions. For these transactions, the fees earned or incurred by the Company are recognized in the period earned or incurred and recorded as interest revenue and brokerage interest expense, respectively, on the Consolidated Statements of Income. The related interest receivable from and the brokerage interest payable to broker-dealers are included in other receivables and in accounts payable and accrued liabilities, respectively, on the Consolidated Balance Sheets.
	Receivable from/Payable to Clients — Receivable from clients primarily consists of margin loans to securities brokerage clients, which are collateralized by client securities, and is carried at the amount receivable, net of an allowance for doubtful accounts that is primarily based on the amount of unsecured margin balances. Payable to clients primarily consists of client cash held in brokerage accounts and is carried at the amount of client cash on deposit. The Company earns interest revenue and pays interest expense on its receivable from client and payable to client balances, respectively. The interest revenue and expense are included in net interest revenue on the Consolidated Statements of Income.
	Investments available for sale — The Company’s investments in marketable securities are carried at fair value and are designated as available-for-sale, except for securities owned by the Company’s broker-dealer subsidiaries, which are accounted for as trading investments and are classified as securities owned on the Consolidated Balance Sheets. Unrealized gains and losses on available-for-sale investments, net of deferred income taxes, are reflected on the Consolidated Balance Sheets as a component of stockholders’ equity. Realized gains and losses on available-for-sale investments are determined on the specific identification method and are reflected on the Consolidated Statements of Income. Declines in fair value of investments that are considered other than temporary are accounted for as realized losses.
	Securities Owned — Securities owned are recorded on a trade-date basis and carried at fair value, and the related changes in fair value are generally included in other revenues on the Consolidated Statements of Income. Securities held by our broker-dealer subsidiaries for trading or investment purposes are included in securities owned on the Consolidated Balance Sheets.
	Property and Equipment — Property and equipment is recorded at cost, net of accumulated depreciation and amortization, except for land, which is recorded at cost. Depreciation is provided using the straight-line method over the estimated useful service lives of the assets, which range from 10 to 40 years for building and building components and three to seven years for all other depreciable property and equipment. Leasehold improvements are amortized over the lesser of the economic useful life of the improvement or the term of the lease.
	Software Development — From the date technological feasibility has been established until beta testing is complete, software development costs are capitalized and included in property and equipment. Once the product is fully functional, such costs are amortized in accordance with the Company’s normal accounting policies. Software development costs that do not meet capitalization criteria are expensed as incurred.
	Goodwill — The Company has recorded goodwill for purchase business combinations to the extent the purchase price of each completed acquisition exceeded the fair value of the net identifiable assets of the acquired company. The Company tests goodwill for impairment on at least an annual basis. In performing the impairment tests, the Company utilizes quoted market prices of the Company’s common stock to estimate the fair value of the Company as a whole. The estimated fair value is then allocated to the Company’s reporting units, if applicable, based on operating revenues, and is compared with the carrying value of the reporting units. No impairment charges have resulted from the annual impairment tests.
	Amortization of Acquired Intangible Assets — Acquired intangible assets with finite lives are amortized on a straight-line basis over their estimated useful lives, ranging from three to 23 years. The acquired intangible asset associated with a trademark license agreement is not subject to amortization because the term of the agreement is considered to be indefinite.
	Long-Lived Assets and Acquired Intangible Assets — The Company reviews its long-lived assets and finite-lived acquired intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. The Company evaluates recoverability by comparing the undiscounted cash flows associated with the asset to the asset’s carrying amount. Long-lived assets classified as “held for sale,” if any, are reported at the lesser of carrying amount or fair value less cost to sell.
	The Company tests its indefinite-lived acquired intangible asset for impairment on at least an annual basis. To determine if the indefinite-lived intangible asset is impaired, the Company first assesses certain qualitative factors. Based on this assessment, if it is determined that more likely than not the fair value of the indefinite-lived intangible asset is less than its carrying amount, the Company performs a quantitative impairment test. No impairment charges have resulted from the annual impairment tests.
	Income Taxes — The Company files a consolidated U.S. income tax return with its subsidiaries on a calendar year basis, combined returns for state tax purposes where required and certain of its subsidiaries file separate state income tax returns where required. Deferred tax assets and liabilities are determined based on the differences between the financial statement carrying amounts and tax bases of assets and liabilities using enacted tax rates expected to apply to taxable income in the periods in which the deferred tax asset or liability is expected to be settled or realized. Uncertain tax positions are recognized if they are more likely than not to be sustained upon examination, based on the technical merits of the position. The amount of tax benefit recognized is the largest amount of benefit that is greater than 50% likely of being realized upon settlement. The Company recognizes interest and penalties, if any, related to income tax matters as part of the provision for income taxes on the Consolidated Statements of Income.
	Capital Stock — The authorized capital stock of the Company consists of a single class of common stock and one or more series of preferred stock as may be authorized for issuance by the Company’s board of directors. Voting, dividend, conversion and liquidation rights of the preferred stock would be established by the board of directors upon issuance of such preferred stock.
	Stock-Based Compensation — The Company measures and recognizes compensation expense based on estimated grant date fair values for all stock-based payment arrangements. Stock-based compensation expense is based on awards expected to vest and therefore is reduced for estimated forfeitures. Forfeitures are estimated at the time of grant based on the Company’s historical forfeiture experience and revised in subsequent periods if actual forfeitures differ from those estimates.
	Comprehensive Income (Loss) — Comprehensive income (loss) primarily consists of net income and unrealized gains (losses) on securities available-for-sale, net of reclassification adjustments and related income taxes.
	Transaction-based Revenues — Client securities trades are recorded on a settlement-date basis with such trades generally settling within three business days after the trade date. Revenues and expenses related to client trades, including revenues from execution agents (also referred to as payment for order flow) and revenues from markups on riskless principal trades in fixed-income securities, are recorded on a trade-date basis. Revenues related to client trades are recorded net of promotional allowances. Securities owned by clients, including those that collateralize margin or similar transactions, are not reflected in the accompanying consolidated financial statements.
	Net Interest Revenue — Net interest revenue primarily consists of income generated by client cash and interest charged to clients on margin balances, net of interest paid to clients on their credit balances. It also includes net interest revenue from securities borrowed and securities loaned transactions. Net interest revenue is recorded when earned.
	Insured Deposit Account Fees — Insured deposit account fees are recognized in the period earned and consist of revenues resulting from the Insured Deposit Account (“IDA”) agreement with TD Bank USA, N.A. (“TD Bank USA”), TD Bank, N.A. and The Toronto-Dominion Bank (“TD”). Under the IDA agreement, TD Bank USA and TD Bank, N.A. (together, the “Depository Institutions”) make available to clients of the Company FDIC-insured money market deposit accounts as either designated sweep vehicles or as non-sweep deposit accounts. The Company provides marketing, recordkeeping and support services for the Depository Institutions with respect to the money market deposit accounts. In exchange for providing these services, the Depository Institutions pay the Company an aggregate marketing fee based on the weighted average yield earned on the client IDA assets, less the actual interest paid to clients, a servicing fee to the Depository Institutions and the cost of FDIC insurance premiums. The IDA agreement is described further in Note 19.
	Investment Product Fees — Investment product fee revenue is recognized in the period earned and consists of revenues earned on client assets invested in money market mutual funds, other mutual funds and certain Company-sponsored investment programs.
	Education Revenue Recognition — The Company recognizes education revenue in accordance with Accounting Standards Codification (“ASC”) 605, Revenue Recognition. Revenue is not recognized until it is realized or realizable and earned. The criteria to meet this guideline are: (a) persuasive evidence of an arrangement exists; (b) delivery has occurred or services have been rendered; (c) the price to the buyer is fixed or determinable; and (d) collectability is reasonably assured. Education revenue is included in other revenues on the Consolidated Statements of Income.
	The Company sells investor education products separately and in various bundles that contain multiple deliverables including on-demand coaching services, website subscriptions, educational workshops, online courses and other products and services. In accordance with ASC 605-25, Multiple-Element Arrangements, sales arrangements with multiple deliverables are divided into separate units of accounting if the deliverables in the arrangement meet the following criteria: (a) the product has value to the client on a standalone basis and (b) delivery or performance of any undelivered item is probable and substantially in the Company’s control. Each of the significant deliverables in our various investor education bundles qualifies as a separate unit of accounting. The relative selling price method is utilized to allocate the arrangement consideration to each deliverable at the inception of the arrangement. The selling price of each deliverable is generally determined by vendor-specific objective evidence, consisting of actual prices charged by the Company when sold separately. In certain arrangements, the Company offers these products bundled together at a discount. The discount is allocated pro rata to each deliverable based on the relative selling price of each deliverable. Deferred revenue arises because the payments are received before the services have been rendered. Deferred revenue is generally recognized into revenue for each deliverable: (a) upon attendance at educational events; (b) upon usage of on-demand services; or (c) over contractual service periods which are usually less than two years.
	The Company provides some limited rights of return in connection with investor education products and services. The Company estimates its returns based on historical experience and maintains an allowance for estimated returns, which is included in deferred revenue on the Consolidated Balance Sheets.
	Advertising — The Company expenses advertising costs the first time the advertising takes place.
	Derivatives and Hedging Activities — The Company occasionally utilizes derivative instruments to manage risks, which may include market price, interest rate and foreign currency risks. The Company does not use derivative instruments for speculative or trading purposes. Derivatives are recorded on the Consolidated Balance Sheets as assets or liabilities at fair value. Derivative instruments properly designated to hedge exposure to changes in the fair value of assets or liabilities are accounted for as fair value hedges. Derivative instruments properly designated to hedge exposure to the variability of expected future cash flows or other forecasted transactions are accounted for as cash flow hedges. The Company formally documents the risk management objective and strategy for each hedge transaction. Derivative instruments that do not qualify for hedge accounting are carried at fair value on the Consolidated Balance Sheets with unrealized gains and losses recorded currently on the Consolidated Statements of Income. Cash flows from derivative instruments accounted for as fair value hedges or cash flow hedges are classified in the same category on the Consolidated Statements of Cash Flows as the cash flows from the items being hedged.
	Earnings Per Share — Basic earnings per share (“EPS”) is computed by dividing net income by the weighted average common shares outstanding for the period. Diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock, except when such assumed exercise or conversion would have an antidilutive effect on EPS.
	Recently Adopted Accounting Pronouncements
	ASU 2011-05 — On October 1, 2012, the Company adopted Accounting Standards Update (“ASU”) 2011-05, Presentation of Comprehensive Income. ASU 2011-05 eliminates the option to present components of other comprehensive income as part of the statement of changes in stockholders’ equity and allows two options for presenting the components of net income and other comprehensive income: (1) in a single continuous statement of comprehensive income or (2) in two separate but consecutive statements, consisting of a statement of net income followed by a separate statement of other comprehensive income. The Company selected the second option for adoption of ASU 2011-05. Adoption of ASU 2011-05 resulted only in changes to the manner in which the components of other comprehensive income are presented in the Company’s financial statements.
	ASU 2011-08 — On October 1, 2012, the Company adopted ASU 2011-08, Testing Goodwill for Impairment. The amendments under ASU 2011-08 allow entities to first assess qualitative factors to determine whether it is necessary to perform the two-step quantitative goodwill impairment test. Under these amendments, an entity is not required to calculate the fair value of a reporting unit unless the entity determines, based on a qualitative assessment, that it is more likely than not that its fair value is less than its carrying amount. The amendments include a number of events and circumstances for entities to consider in conducting the qualitative assessment. Entities have the option to bypass the qualitative assessment for any reporting unit in any period and proceed directly to performing the first step of the two-step quantitative goodwill impairment test. Adoption of ASU 2011-08 did not have an impact on the Company’s financial statements.
	ASU 2012-02 — On October 1, 2012 the Company adopted ASU 2012-02, Testing Indefinite-Lived Intangible Assets for Impairment. The amendments in ASU 2012-02 allow entities to first to assess qualitative factors to determine whether the existence of events and circumstances indicates that it is more likely than not that an indefinite-lived intangible asset is impaired. If, after assessing the totality of events and circumstances, an entity concludes that it is not more likely than not that the indefinite-lived intangible asset is impaired, then the entity is not required to take further action. However, if an entity concludes otherwise, then it is required to determine the fair value of the indefinite-lived intangible asset and perform the quantitative impairment test by comparing the fair value with the carrying amount. Entities have the option to bypass the qualitative assessment for any indefinite-lived intangible asset in any period and proceed directly to performing the quantitative impairment test. Adoption of ASU 2012-02 did not have an impact on the Company’s financial statements.
	Recently Issued Accounting Pronouncements
	ASU 2011-11 — In December 2011, the Financial Accounting Standards Board (“FASB”) issued ASU 2011-11, Disclosures about Offsetting Assets and Liabilities, and further clarified the scope of these disclosures by issuing ASU 2013-01, Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities, in January 2013. The amendments in these ASUs will enhance disclosures by requiring improved information about financial and derivative instruments, including bifurcated embedded derivatives, repurchase agreements and reverse repurchase agreements, and securities borrowing and securities lending transactions that are either (1) offset (netting assets and liabilities) in accordance with Section 210-20-45 or Section 815-10-45 of the FASB Accounting Standards Codification or (2) subject to an enforceable master netting arrangement or similar agreement. ASU 2011-11 and ASU 2013-01 are effective for annual periods beginning on or after January 1, 2013, and interim periods within those annual periods, and require retrospective disclosures for comparative periods presented. Therefore, these ASUs will be effective for the Company’s fiscal year beginning October 1, 2013. Adoption of ASU 2011-11 and ASU 2013-01 is not expected to have a material impact on the Company’s financial statements.

Goodwill_and_Acquired_Intangib

Goodwill and Acquired Intangible Assets	12 Months Ended
	Sep. 30, 2013
Goodwill And Intangible Assets Disclosure [Abstract]	'
Goodwill and Acquired Intangible Assets	'
	2	Goodwill and Acquired Intangible Assets
	The Company has recorded goodwill for purchase business combinations to the extent the purchase price of each completed acquisition exceeded the fair value of the net identifiable tangible and intangible assets of each acquired company. There were no material changes in the carrying amount of goodwill during the fiscal years ended September 30, 2013 and 2012.
	Acquired intangible assets consist of the following (dollars in millions):
			September 30,
			2013							2012
			Gross		Accumulated			Net		Gross		Accumulated			Net
			Carrying		Amortization			Carrying		Carrying		Amortization			Carrying
			Amount					Amount		Amount					Amount
	Client relationships		$	1,228	$	(569	)	$	659	$	1,228	$	(493	)	$	735
	Technology and content			99		(63	)		36		99		(48	)		51
	Trademark license			146		—			146		146		—			146
			$	1,473	$	(632	)	$	841	$	1,473	$	(541	)	$	932
	Amortization expense on acquired intangible assets was $91 million, $92 million and $97 million for fiscal years 2013, 2012 and 2011, respectively. Estimated future amortization expense for acquired intangible assets outstanding as of September 30, 2013 is as follows (dollars in millions):
	Fiscal Year		Estimated
			Amortization
			Expense
	2014		$	90
	2015			90
	2016			85
	2017			76
	2018			72
	Thereafter (to 2025)			282
	Total		$	695

Cash_and_Cash_Equivalents

Cash and Cash Equivalents	12 Months Ended
	Sep. 30, 2013
Cash And Cash Equivalents [Abstract]	'
Cash and Cash Equivalents	'
	3	Cash and Cash Equivalents
	The Company’s cash and cash equivalents is summarized in the following table (dollars in millions):
			September 30,
			2013		2012
	Corporate		$	429	$	403
	Broker-dealer subsidiaries			540		406
	Trust company subsidiary			74		95
	Investment advisory subsidiaries			19		11
	Total		$	1,062	$	915
	Capital requirements may limit the amount of cash available for dividend from the broker-dealer and trust company subsidiaries to the parent company. Most of the trust company cash and cash equivalents arises from client transactions in the process of settlement, and therefore is generally not available for corporate purposes. Cash and cash equivalents of the investment advisory subsidiaries is generally not available for corporate purposes.

Cash_and_Investments_Segregate

Cash and Investments Segregated and on Deposit for Regulatory Purposes	12 Months Ended
	Sep. 30, 2013
Receivables [Abstract]	'
Cash and Investments Segregated and on Deposit for Regulatory Purposes	'
	4	Cash and Investments Segregated and on Deposit for Regulatory Purposes
	Cash and investments segregated and on deposit for regulatory purposes consists of the following (dollars in millions):
			September 30,
			2013		2012
	Reverse repurchase agreements (collateralized by U.S. government debt securities)		$	2,618	$	2,181
	U.S. government debt securities			1,995		1,564
	Cash in demand deposit accounts			1,154		179
	Cash on deposit with futures commission merchant			77		96
	U.S. government debt securities on deposit with futures commission merchant			50		10
	Total		$	5,894	$	4,030

Receivable_from_and_Payable_to

Receivable from and Payable to Brokers, Dealers and Clearing Organizations	12 Months Ended
	Sep. 30, 2013
Brokers And Dealers [Abstract]	'
Receivable from and Payable to Brokers, Dealers and Clearing Organizations	'
	5	Receivable from and Payable to Brokers, Dealers and Clearing Organizations
	Amounts receivable from and payable to brokers, dealers and clearing organizations consist of the following (dollars in millions):
			September 30,
			2013		2012
	Receivable:
	Deposits paid for securities borrowed		$	1,220	$	924
	Broker-dealers			9		2
	Deposits with clearing organizations			115		177
	Securities failed to deliver			4		7
	Total		$	1,348	$	1,110
	Payable:
	Deposits received for securities loaned		$	1,948	$	1,940
	Broker-dealers			2		3
	Clearing organizations			15		—
	Securities failed to receive			8		49
	Total		$	1,973	$	1,992

Allowance_for_Doubtful_Account

Allowance for Doubtful Accounts on Receivables	12 Months Ended
	Sep. 30, 2013
Valuation And Qualifying Accounts [Abstract]	'
Allowance for Doubtful Accounts on Receivables	'
	6	Allowance for Doubtful Accounts on Receivables
	The following table summarizes activity in the Company’s allowance for doubtful accounts on client and other receivables for the fiscal years indicated (dollars in millions):
			2013			2012			2011
	Beginning balance		$	21		$	18		$	11
	Provision for (recovery of) doubtful accounts, net			(1	)		9			9
	Write-off of doubtful accounts			(5	)		(6	)		(2	)
	Ending balance		$	15		$	21		$	18

Investments_AvailableForSale

Investments Available-For-Sale	12 Months Ended
	Sep. 30, 2013
Investments Debt And Equity Securities [Abstract]	'
Investments Available-For-Sale	'
	7	Investments Available-For-Sale
	As of September 30, 2012, the Company owned 39,000 shares of Knight Capital Group, Inc. (“Knight”) 2% convertible preferred stock. Each preferred share was convertible to 666.667 shares of Knight Class A common stock. On February 28, 2013, all of the Company’s preferred shares were converted into approximately 26 million shares of Knight Class A common stock.
	On July 1, 2013, Knight completed its merger with GETCO Holding Company, LLC (“GETCO”), whereby Knight and GETCO were combined into KCG Holdings, Inc. (“KCG”), a new publicly traded holding corporation. The Company received merger consideration with an aggregate fair value of $95 million in exchange for its Knight Class A common stock, consisting of approximately $69 million in cash and approximately 2.5 million shares of KCG common stock with a fair value of approximately $26 million based on the final quoted market price of the Knight Class A common stock immediately prior to the merger. The Company realized a pre-tax gain of approximately $54 million for this transaction, which is included in gain on investments, net on the Consolidated Statements of Income. As of September 30, 2013, the Company owned approximately 1.5 million shares of KCG common stock.

Property_and_Equipment

Property and Equipment	12 Months Ended
	Sep. 30, 2013
Property Plant And Equipment [Abstract]	'
Property and Equipment	'
	8	Property and Equipment
	Property and equipment consists of the following (dollars in millions):
			September 30,
			2013			2012
	Computer equipment		$	205		$	190
	Building and building components			198			—
	Building construction in process			—			164
	Leasehold improvements			148			147
	Software			144			117
	Land			17			13
	Other property and equipment			67			48
				779			679
	Less: Accumulated depreciation and amortization			(282	)		(235	)
	Property and equipment, net		$	497		$	444

Longterm_Debt_and_Credit_Facil

Long-term Debt and Credit Facilities	12 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Long-term Debt and Credit Facilities	'
	9	Long-term Debt and Credit Facilities
	Long-term debt consists of the following (dollars in millions):
	September 30, 2013		Face			Unamortized			Fair Value			Net Carrying
			Value			Discount			Adjustment(1)			Value
	Senior Notes:
	4.150% Senior Notes due 2014		$	500		$	—		$	15		$	515
	5.600% Senior Notes due 2019			500			—			37			537
	Total long-term debt		$	1,000		$	—		$	52		$	1,052
	September 30, 2012		Face			Unamortized			Fair Value			Net Carrying
			Value			Discount			Adjustment(1)			Value
	Senior Notes:
	2.950% Senior Notes due 2012		$	250		$	—		$	1		$	251
	4.150% Senior Notes due 2014			500			—			27			527
	5.600% Senior Notes due 2019			500			(1	)		68			567
	Total long-term debt		$	1,250		$	(1	)	$	96		$	1,345
	-1	Fair value adjustments relate to changes in the fair value of the debt while in a fair value hedging relationship. See “Interest Rate Swaps” below.
	Fiscal year maturities on long-term debt outstanding at September 30, 2013 are as follows (dollars in millions):
	2014		$	—
	2015			500
	2016			—
	2017			—
	2018			—
	Thereafter			500
	Total		$	1,000
	Senior Notes — On November 25, 2009 the Company sold, through a public offering, $1.25 billion aggregate principal amount of unsecured senior notes, consisting of $250 million aggregate principal amount of 2.950% Senior Notes due December 1, 2012 (the “2012 Notes”), $500 million aggregate principal amount of 4.150% Senior Notes due December 1, 2014 (the “2014 Notes”) and $500 million aggregate principal amount of 5.600% Senior Notes due December 1, 2019 (the “2019 Notes” and, collectively with the 2012 Notes and the 2014 Notes, the “Senior Notes”). The Senior Notes were issued at an aggregate discount of $1 million, which is being amortized to interest expense over the terms of the respective Senior Notes. Interest on the Senior Notes is payable semi-annually in arrears on June 1 and December 1 of each year. On December 1, 2012, the Company paid in full the outstanding principal balance under the 2012 Notes.
	The Senior Notes are jointly and severally and fully and unconditionally guaranteed by each of the Company’s current and future subsidiaries that is or becomes a borrower or a guarantor under the TD Ameritrade Holding Corporation Credit Agreement, dated as of June 28, 2011, as described below. Currently, the only subsidiary guarantor of the obligations under the Senior Notes is TD Ameritrade Online Holdings Corp. (“TDAOH”). The Senior Notes and the guarantee by TDAOH are the general senior unsecured obligations of the Company and TDAOH.
	The Company may redeem each series of the Senior Notes, in whole at any time or in part from time to time, at a redemption price equal to the greater of (a) 100% of the principal amount of the notes being redeemed, and (b) the sum of the present values of the remaining scheduled payments of principal and interest on the notes being redeemed, discounted to the date of redemption on a semi-annual basis at the comparable U.S. Treasury rate, plus: 30 basis points in the case of the 2014 Notes and 35 basis points in the case of the 2019 Notes, plus, in each case, accrued and unpaid interest to the date of redemption.
	Interest Rate Swaps — The Company is exposed to changes in the fair value of its fixed-rate Senior Notes resulting from interest rate fluctuations. To hedge this exposure, on December 30, 2009, the Company entered into fixed-for-variable interest rate swaps on the 2012 Notes and 2014 Notes for notional amounts of $250 million and $500 million, respectively, with maturity dates matching the respective maturity dates of the 2012 Notes and 2014 Notes. In addition, on January 7, 2011, the Company entered into a fixed-for-variable interest rate swap on the 2019 Notes for a notional amount of $500 million, with a maturity date matching the maturity date of the 2019 Notes. The interest rate swaps effectively change the fixed-rate interest on the Senior Notes to variable-rate interest. Under the terms of the interest rate swap agreements, the Company receives semi-annual fixed-rate interest payments based on the same rates applicable to the Senior Notes, and makes quarterly variable-rate interest payments based on three-month LIBOR plus (a) 0.9693% for the swap on the 2012 Notes, (b) 1.245% for the swap on the 2014 Notes and (c) 2.3745% for the swap on the 2019 Notes. On December 1, 2012, the interest rate swap on the 2012 Notes expired. As of September 30, 2013, the weighted average effective interest rate on the Senior Notes was 2.07%.
	The interest rate swaps are accounted for as fair value hedges and qualify for the shortcut method of accounting. Changes in the payment of interest resulting from the interest rate swaps are recorded in interest on borrowings on the Consolidated Statements of Income. Changes in fair value of the interest rate swaps are completely offset by changes in fair value of the related notes, resulting in no effect on net income. The following table summarizes gains and losses resulting from changes in the fair value of the interest rate swaps and the hedged fixed-rate debt for the fiscal years indicated (dollars in millions):
			2013			2012			2011
	Gain (loss) on fair value of interest rate swaps		$	(44	)	$	8		$	39
	Gain (loss) on fair value of hedged fixed-rate debt			44			(8	)		(39	)
	Net gain (loss) recorded in interest on borrowings		$	—		$	—		$	—
	The following table summarizes the fair value of outstanding derivatives designated as hedging instruments on the Consolidated Balance Sheets (dollars in millions):
			September 30,
			2013			2012
	Derivatives recorded under the caption Other assets:
	Interest rate swap assets		$	52		$	96
	The interest rate swaps are subject to counterparty credit risk. Credit risk is managed by limiting activity to approved counterparties that meet a minimum credit rating threshold and by entering into credit support agreements. The bilateral credit support agreements related to the interest rate swaps require daily collateral coverage, in the form of cash or U.S. Treasury securities, for the aggregate fair value of the interest rate swaps. As of September 30, 2013 and 2012, the interest rate swap counterparties for the Senior Notes had pledged $67 million and $113 million of collateral, respectively, to the Company in the form of cash. A liability for collateral pledged to the Company in the form of cash is recorded in accounts payable and accrued liabilities on the Consolidated Balance Sheets.
	TD Ameritrade Holding Corporation Credit Agreement — On June 28, 2011, TD Ameritrade Holding Corporation (the “Parent”) entered into a credit agreement consisting of a senior unsecured revolving credit facility in the aggregate principal amount of $300 million (the “Parent Revolving Facility”). The maturity date of the Parent Revolving Facility is June 28, 2014. On December 28, 2012, the Company borrowed $275 million under the Parent Revolving Facility. The Company used the proceeds to fund a $0.50 per share special cash dividend, paid on the Company’s common stock on December 31, 2012. During fiscal 2013, the Company paid in full the outstanding principal balance under the Parent Revolving Facility. There were no borrowings outstanding under the Parent Revolving Facility as of September 30, 2013 and 2012.
	The applicable interest rate under the Parent Revolving Facility is calculated as a per annum rate equal to, at the option of the Parent, (a) LIBOR plus an interest rate margin (“Parent LIBOR loans”) or (b) (i) the highest of (x) the prime rate, (y) the federal funds effective rate plus 0.50% or (z) one-month LIBOR plus 1.00%, plus (ii) an interest rate margin (“Base Rate loans”). The interest rate margin ranges from 1.25% to 2.25% for Parent LIBOR loans and from 0.25% to 1.25% for Base Rate loans, determined by reference to the Company’s public debt ratings. The Parent is obligated to pay a commitment fee ranging from 0.15% to 0.375% on any unused amount of the Parent Revolving Facility, determined by reference to the Company’s public debt ratings. As of September 30, 2013, the interest rate margin would have been 1.25% for Parent LIBOR loans and 0.25% for Base Rate loans, and the commitment fee was 0.15%, each determined by reference to the Company’s public debt ratings.
	The obligations under the Parent Revolving Facility are guaranteed by TDAOH and each “significant subsidiary” (as defined in SEC Rule 1-02(w) of Regulation S-X) of the Parent, other than broker-dealer subsidiaries, futures commission merchant subsidiaries and controlled foreign corporations. Currently, the only subsidiary guarantor of the obligations under the Parent Revolving Facility is TDAOH.
	The Parent Revolving Facility contains negative covenants that limit or restrict, subject to certain exceptions, the incurrence of liens, indebtedness of subsidiaries, mergers, consolidations, transactions with affiliates, change in nature of business and the sale of all or substantially all of the assets of the Company. The Parent is also required to maintain compliance with a maximum consolidated leverage ratio covenant and a minimum consolidated interest coverage ratio covenant, and the Company’s broker-dealer subsidiaries are required to maintain compliance with a minimum regulatory net capital covenant. The Company was in compliance with all covenants under the Parent Revolving Facility as of September 30, 2013.
	TD Ameritrade Clearing, Inc. Credit Agreement — On June 28, 2011, TD Ameritrade Clearing, Inc. (“TDAC”), the Company’s clearing broker-dealer subsidiary, entered into a credit agreement consisting of a senior unsecured revolving credit facility in the aggregate principal amount of $300 million (the “TDAC Revolving Facility”). The maturity date of the TDAC Revolving Facility is June 28, 2014.
	The applicable interest rate under the TDAC Revolving Facility is calculated as a per annum rate equal to, at the option of TDAC, (a) LIBOR plus an interest rate margin (“TDAC LIBOR loans”) or (b) the federal funds effective rate plus an interest rate margin (“Fed Funds Rate loans”). The interest rate margin ranges from 1.00% to 2.00% for both TDAC LIBOR loans and Fed Funds Rate loans, determined by reference to the Company’s public debt ratings. TDAC is obligated to pay a commitment fee ranging from 0.125% to 0.30% on any unused amount of the TDAC Revolving Facility, determined by reference to the Company’s public debt ratings. As of September 30, 2013, the interest rate margin would have been 1.00% for both TDAC LIBOR loans and Fed Funds Rate loans, and the commitment fee was 0.125%, each determined by reference to the Company’s public debt ratings. There were no borrowings outstanding under the TDAC Revolving Facility as of September 30, 2013 and 2012.
	The TDAC Revolving Facility contains negative covenants that limit or restrict, subject to certain exceptions, the incurrence of liens, indebtedness of TDAC, mergers, consolidations, change in nature of business and the sale of all or substantially all of the assets of TDAC. TDAC is also required to maintain minimum tangible net worth and is required to maintain compliance with minimum regulatory net capital requirements. TDAC was in compliance with all covenants under the TDAC Revolving Facility as of September 30, 2013.

Income_Taxes

Income Taxes	12 Months Ended
	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'
Income Taxes	'
	10	Income Taxes
	Provision for income taxes is comprised of the following for the fiscal years indicated (dollars in millions):
			2013			2012			2011
	Current expense:
	Federal		$	370		$	314		$	357
	State			33			1			20
				403			315			377
	Deferred expense (benefit):
	Federal			(2	)		(2	)		(5	)
	State			12			7			7
				10			5			2
	Provision for income taxes		$	413		$	320		$	379
	A reconciliation of the federal statutory tax rate to the effective tax rate applicable to pre-tax income follows for the fiscal years indicated:
			2013			2012			2011
	Federal statutory rate			35	%		35	%		35	%
	State taxes, net of federal tax effect			2.6			2.1			2.3
	Adjustments to estimated state income taxes			0.4			0.1			(0.1	)
	Interest recorded on unrecognized tax benefits, net			0.3			0.1			0.5
	Reversal of accruals for unrecognized tax benefits			(0.3	)		(1.7	)		(0.5	)
	Reversal of capital loss valuation allowance			—			(0.4	)		—
	Other			—			0.1			0.1
				38	%		35.3	%		37.3	%
	The Company’s effective income tax rate for fiscal year 2013 was 38.0%, compared to 35.3% and 37.3% for fiscal years 2012 and 2011, respectively. The provision for income taxes for fiscal year 2013 included $6 million of favorable resolutions of state income tax matters, which was mostly offset by $4 million of unfavorable deferred income tax adjustments resulting from state income tax law changes. The provision for income taxes for fiscal year 2012 was significantly lower than normal primarily due to $19 million of favorable resolutions of state income tax matters and a $3 million benefit resulting from the reversal of a valuation allowance related to a capital loss carryover. These items favorably impacted the Company’s earnings for fiscal year 2012 by approximately four cents per share. The provision for income taxes for fiscal year 2011 was somewhat lower than normal due to $6 million of favorable resolutions of state income tax matters and $1 million of favorable deferred income tax adjustments resulting from state income tax law changes. These items favorably impacted the Company’s earnings for fiscal year 2011 by approximately one cent per share.
	Deferred tax assets (liabilities) are comprised of the following (dollars in millions):
			September 30,
			2013			2012
	Deferred tax assets:
	Accrued liabilities		$	72		$	69
	Intangible assets, state tax benefit			12			15
	Stock-based compensation			36			30
	Allowance for doubtful accounts			6			8
	Unrealized tax gain on IDA agreement			—			9
	Operating loss carryforwards			21			40
	Other deferred tax assets			3			6
	Gross deferred tax assets			150			177
	Less: Valuation allowance			(18	)		(37	)
	Net deferred tax assets			132			140
	Deferred tax liabilities:
	Property and intangible assets			(478	)		(478	)
	Unrealized investment gains			—			(10	)
	Other deferred tax liabilities			(5	)		(4	)
	Total deferred tax liabilities			(483	)		(492	)
	Net deferred tax liabilities		$	(351	)	$	(352	)
	Included in deferred tax assets above as of September 30, 2013 and 2012, is approximately $1 million and $2 million, respectively, of deferred tax benefits relating to intangible asset amortization deductions expected to be claimed in various state taxing jurisdictions, which may not be offset by deferred tax liabilities arising from different taxing jurisdictions on the Consolidated Balance Sheets. These amounts are presented separately as assets on the Consolidated Balance Sheets.
	The unrealized tax gain on IDA agreement in the table above was attributable to the tax basis in the Company’s marketing fee associated with the IDA agreement described in Note 19. The tax basis represented tax gains recorded based on the increase in the fair market values of the underlying securities held by the Depository Institutions, which were supported by the client insured deposit account balances.
	As of September 30, 2013, the Company has recorded a tax benefit for approximately $3 million of federal net operating loss carryover that was acquired as part of the thinkorswim Group Inc. acquisition in fiscal 2009. The net operating loss expires in 2019, and is subject to substantial annual limitations on the utilization of the net operating loss. The amount of tax benefit recorded in the financial statements represents the amount that is more likely than not to be realized within the carryforward period. At September 30, 2013, subsidiaries of the Company have approximately $340 million of separate state operating loss carryforwards. These carryforwards expire between fiscal 2014 and 2032. Because the realization of the tax benefit from state loss carryforwards is dependent on certain subsidiaries generating sufficient state taxable income in future periods, as well as annual limitations on future utilization, the Company has provided a valuation allowance against the computed benefit in order to reflect the tax benefit expected to be realized. The $19 million decrease in the valuation allowance from September 30, 2012 to September 30, 2013 was primarily due to expiration of certain state net operating loss carryforwards during fiscal 2013.
	A reconciliation of the activity related to unrecognized tax benefits follows for the fiscal years indicated (dollars in millions):
			2013			2012			2011
	Beginning balance		$	139		$	145		$	149
	Additions based on tax positions related to the current year			8			10			10
	Additions for tax positions of prior years			2			8			7
	Reductions for tax positions of prior years			(5	)		(3	)		(12	)
	Reductions due to settlements with taxing authorities			(1	)		(5	)		(1	)
	Reductions due to lapsed statute of limitations			(6	)		(16	)		(8	)
	Ending balance		$	137		$	139		$	145
	The balance of unrecognized tax benefits as of September 30, 2013 was $137 million ($89 million net of the federal benefit on state matters), all of which, if recognized, would favorably affect the effective income tax rate in any future periods. The balance of unrecognized tax benefits as of September 30, 2012 was $139 million ($91 million net of the federal benefit on state matters), of which $89 million (net of the federal benefit on state matters) represents the amount that, if recognized, would favorably affect the effective income tax rate in any future periods. The Company’s income tax returns are subject to review and examination by federal, state and local taxing authorities. The federal returns for 2010 through 2012 remain open under the statute of limitations. The years open to examination by state and local government authorities vary by jurisdiction, but the statute of limitations is generally three to four years from the date the tax return is filed. It is reasonably possible that the gross unrecognized tax benefits as of September 30, 2013 could decrease by up to $40 million ($26 million net of the federal benefit on state matters) within the next twelve months as a result of settlements of certain examinations or expiration of the statute of limitations with respect to other tax filings.
	The Company recognized interest and penalties expense (net of the federal benefit) of $2 million and $5 million for fiscal years 2013 and 2011, respectively. The Company recognized $3 million of net benefits for interest and penalties (net of the federal income tax effect) on the Consolidated Statement of Income for fiscal year 2012, due to the favorable resolution of an uncertain tax position. As of September 30, 2013 and 2012, accrued interest and penalties related to unrecognized tax benefits was $48 million and $44 million, respectively.

Capital_Requirements

Capital Requirements

12 Months Ended

Sep. 30, 2013

Text Block [Abstract]

'

Capital Requirements

'

11

Capital Requirements

The Company’s broker-dealer subsidiaries are subject to the SEC Uniform Net Capital Rule (Rule 15c3-1 under the Exchange Act), administered by the SEC and FINRA, which requires the maintenance of minimum net capital, as defined. Net capital and the related net capital requirement may fluctuate on a daily basis.

TDAC, the Company’s clearing broker-dealer subsidiary, and TD Ameritrade, Inc., the Company’s introducing broker-dealer subsidiary, compute net capital under the alternative method as permitted by Rule 15c3-1. TDAC is required to maintain minimum net capital of the greater of $1.5 million, which is based on the type of business conducted by the broker-dealer, or 2% of aggregate debit balances arising from client transactions.

Under Rule 15c3-1, TD Ameritrade, Inc. is required to maintain minimum net capital of the greater of $250,000 or 2% of aggregate debit balances. As a futures commission merchant registered with the CFTC, TD Ameritrade, Inc. is also subject to CFTC Regulation 1.17 under the Commodity Exchange Act, administered by the CFTC and the NFA, which requires the maintenance of minimum net capital of the greatest of (a) $1.0 million, (b) its futures risk-based capital requirement, equal to 8% of the total risk margin requirement for all futures positions carried by the futures commission merchant in client and nonclient accounts, or (c) its Rule 15c3-1 net capital requirement.

Under the alternative method, a broker-dealer may not repay any subordinated borrowings, pay cash dividends or make any unsecured advances or loans to its parent company or employees if such payment would result in a net capital amount of (a) less than 5% of aggregate debit balances, (b) less than 110% of its risk-based capital requirement under CFTC Regulation 1.17, or (c) less than 120% of its minimum dollar requirement. These net capital thresholds, which are specified in Exchange Act Rule 17a-11 and CFTC Regulation 1.12, are typically referred to as “early warning” net capital thresholds.

Net capital and net capital requirements for the Company’s broker-dealer subsidiaries are summarized in the following tables (dollars in millions):

TD Ameritrade Clearing, Inc.

Date

Net Capital

Required

Net Capital

Net Capital in

Ratio of

Net Capital (2%

in Excess of

Excess of

Net Capital

of Aggregate

Required

Early Warning

to Aggregate

Debit Balances)

Net Capital

Threshold

Debit Balances

(5% of

Aggregate

Debit Balances)

30-Sep-13

$

1,302

$

222

$

1,080

$

746

11.7

%

30-Sep-12

$

1,302

$

203

$

1,099

$

796

12.86

%

TD Ameritrade, Inc.

Date

Net Capital

Required Net

Net Capital

Net Capital in

Capital

in Excess of

Excess of

(8% of Total

Required

Early Warning

Risk Margin)

Net Capital

Threshold

(110% of

Required

Net Capital)

30-Sep-13

$

305

$

10

$

295

$

294

30-Sep-12

$

261

$

8

$

253

$

252

The Company’s non-depository trust company subsidiary, TD Ameritrade Trust Company (“TDATC”), is subject to capital requirements established by the State of Maine, which require TDATC to maintain minimum Tier 1 capital, as defined. TDATC’s Tier 1 capital was $23 million and $20 million as of September 30, 2013 and 2012, respectively, which exceeded the required Tier 1 capital by $8 million and $10 million, respectively.

Stockbased_Compensation

Stock-based Compensation	12 Months Ended
	Sep. 30, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Stock-based Compensation	'
	12	Stock-based Compensation
	The Company has two stock incentive plans under which Company stock-based awards may be granted: the TD Ameritrade Holding Corporation Long-Term Incentive Plan (the “LTIP”) and the 2006 Directors Incentive Plan (the “Directors Plan”). The Company also assumed stock incentive plans in connection with past business combinations. New stock awards can no longer be granted under the assumed plans.
	The LTIP authorizes the award of options to purchase common stock, common stock appreciation rights, restricted stock, restricted stock units, performance shares and performance units. Under the LTIP, 42,104,174 shares of the Company’s common stock are reserved for issuance to eligible employees, consultants and non-employee directors. The Directors Plan authorizes the award of options to purchase common stock, common stock appreciation rights, restricted stock units and restricted stock. Under the Directors Plan, 1,830,793 shares of the Company’s common stock are reserved for issuance to non-employee directors.
	Stock options, except for replacement options granted in connection with business combinations, are granted by the Company with an exercise price not less than the fair market value of the Company’s common stock on the grant date. Stock options generally vest over a one- to four-year period and expire 10 years after the grant date. Restricted Stock Units (“RSUs”) are awards that entitle the holder to receive shares of Company common stock following a vesting period. RSUs granted to employees generally vest after the completion of a three-year period. RSUs granted to non-employee directors generally vest over a one-year period.
	Stock-based compensation expense was $29 million, $41 million and $35 million for fiscal years 2013, 2012 and 2011, respectively. The related income tax benefits were $11 million, $15 million and $13 million for fiscal years 2013, 2012 and 2011, respectively.
	The following is a summary of option activity in the Company’s stock incentive plans for the fiscal year ended September 30, 2013:
			Number of			Weighted		Weighted		Aggregate
			Options			Average		Average		Intrinsic
			(in thousands)			Exercise		Remaining		Value
						Price		Contractual		(in millions)
								Term (Years)
	Outstanding at beginning of year			7,190		$	9.31
	Exercised			(4,600	)	$	4.13
	Expired			(47	)	$	26.52
	Outstanding at end of year			2,543		$	18.36		5.1	$	20
	Exercisable at end of year			2,515		$	18.34		5.1	$	20
	The Company measures the fair value of stock options using a Black-Scholes valuation model as of the date of grant. No options were granted during fiscal years 2013, 2012 and 2011. The total intrinsic value of options exercised during fiscal years 2013, 2012 and 2011 was $65 million, $21 million and $10 million, respectively. As of September 30, 2013, there was no unrecognized compensation cost related to nonvested stock option awards.
	The Company measures the fair value of RSUs based upon the volume-weighted average market price of the underlying common stock as of the date of grant. RSUs are amortized over their applicable vesting period using the straight-line method, reduced by expected forfeitures.
	The following is a summary of RSU activity in the Company’s stock incentive plans for the fiscal year ended September 30, 2013:
			Number of			Weighted
			Units			Average
			(in thousands)			Grant Date
						Fair Value
	Nonvested at beginning of year			4,139		$	17.74
	Granted			2,172		$	16.38
	Dividend equivalents			235		$	16.92
	Vested			(861	)	$	19.13
	Forfeited			(334	)	$	17.15
	Nonvested at end of year			5,351		$	17
	As of September 30, 2013, there was $27 million of estimated unrecognized compensation cost related to nonvested RSUs, which was expected to be recognized over a weighted average period of 1.8 years.
	Although the Company does not have a formal policy for issuing shares upon stock option exercises, such shares are generally issued from treasury stock. The Stockholders Agreement entered into in connection with the acquisition of TD Waterhouse requires the Company to repurchase its common stock from time to time to offset dilution resulting from stock option exercises and other stock awards subsequent to the acquisition. As of September 30, 2013, the Company was not obligated to repurchase additional shares pursuant to the Stockholders Agreement. The Company cannot estimate the amount and timing of repurchases that may be required as a result of future stock issuances.

Employee_Benefit_Plans

Employee Benefit Plans	12 Months Ended
	Sep. 30, 2013
Compensation And Retirement Disclosure [Abstract]	'
Employee Benefit Plans	'
	13	Employee Benefit Plans
	The Company has a 401(k) and profit-sharing plan under which annual profit-sharing contributions are determined at the discretion of the board of directors. The Company also makes matching contributions pursuant to the plan document. Profit-sharing and matching contributions expense was $28 million for each of fiscal years 2013 and 2012 and $31 million for fiscal year 2011.

Earnings_Per_Share

Earnings Per Share	12 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Earnings Per Share	'
	14	Earnings Per Share
	The following is a reconciliation of the numerator and denominator used in the computation of basic and diluted earnings per share for the fiscal years indicated (in millions, except per share amounts):
			2013		2012		2011
	Net income		$	675	$	586	$	638
	Weighted average shares outstanding — basic			549		548		570
	Effect of dilutive securities:
	Common stock equivalent shares related to stock-based compensation			5		6		6
	Weighted average shares outstanding — diluted(1)			554		554		576
	Earnings per share — basic		$	1.23	$	1.07	$	1.12
	Earnings per share — diluted		$	1.22	$	1.06	$	1.11
	-1	The Company excluded from the calculation of diluted earnings per share 0.7 million, 2.5 million and 1.5 million shares underlying stock-based compensation awards for the fiscal years ended September 30, 2013, 2012 and 2011, respectively, because their inclusion would have been antidilutive.

Commitments_and_Contingencies

Commitments and Contingencies	12 Months Ended
	Sep. 30, 2013
Commitments And Contingencies Disclosure [Abstract]	'
Commitments and Contingencies	'
	15	Commitments and Contingencies
	Lease Commitments — The Company has various non-cancelable operating leases on facilities and certain office equipment requiring annual payments as follows (dollars in millions):
	Fiscal Year		Minimum		Sublease			Net Lease
			Lease		Income			Commitments
			Payments
	2014		$	52	$	(1	)	$	51
	2015			48		(1	)		47
	2016			45		(1	)		44
	2017			45		(2	)		43
	2018			42		(1	)		41
	Thereafter (to 2029)			109		(1	)		108
	Total		$	341	$	(7	)	$	334
	A majority of the leases for the Company’s branch offices contain provisions for renewal at the Company’s option. Rental expense, net of sublease income, was approximately $54 million for fiscal year 2013 and $50 million for each of fiscal years 2012 and 2011.
	As of September 30, 2012, the Company had capital leases on computer equipment. During fiscal year 2013, these capital lease obligations were paid in full. The amortization of equipment under capital leases is included in depreciation and amortization on the Consolidated Statements of Income.
	Reserve Fund Matters — During September 2008, The Reserve, an independent mutual fund company, announced that the net asset value of the Reserve Yield Plus Fund declined below $1.00 per share. The Yield Plus Fund was not a money market mutual fund, but its stated objective was to maintain a net asset value of $1.00 per share. TD Ameritrade, Inc.’s clients continue to hold shares in the Yield Plus Fund (now known as “Yield Plus Fund – In Liquidation”), which is being liquidated. On July 23, 2010, The Reserve announced that through that date it had distributed approximately 94.8% of the Yield Plus Fund assets as of September 15, 2008 and that the Yield Plus Fund had approximately $39.7 million in total remaining assets. The Reserve stated that the fund’s Board of Trustees has set aside almost the entire amount of the remaining assets to cover potential claims, fees and expenses. The Company estimates that TD Ameritrade, Inc. clients’ current positions held in the Reserve Yield Plus Fund amount to approximately 79% of the fund.
	On January 27, 2011, TD Ameritrade, Inc. entered into a settlement with the SEC, agreeing to pay $0.012 per share to all eligible current or former clients that purchased shares of the Yield Plus Fund and continued to own those shares. Clients who purchased Yield Plus Fund shares through independent registered investment advisors were not eligible for the payment. In February 2011, the Company paid clients approximately $10 million under the settlement agreement.
	In November 2008, a purported class action lawsuit was filed with respect to the Yield Plus Fund. The lawsuit is captioned Ross v. Reserve Management Company, Inc. et al. and is pending in the U.S. District Court for the Southern District of New York. The Ross lawsuit is on behalf of persons who purchased shares of Reserve Yield Plus Fund. On November 20, 2009, the plaintiffs filed a first amended complaint naming as defendants the fund’s advisor, certain of its affiliates and the Company and certain of its directors, officers and shareholders as alleged control persons. The complaint alleges claims of violations of the federal securities laws and other claims based on allegations that false and misleading statements and omissions were made in the Reserve Yield Plus Fund prospectuses and in other statements regarding the fund. The complaint seeks an unspecified amount of compensatory damages including interest, attorneys’ fees, rescission, exemplary damages and equitable relief. On January 19, 2010, the defendants submitted motions to dismiss the complaint. The motions are pending.
	The Company estimates that its clients’ current aggregate shortfall, based on the original par value of their holdings in the Yield Plus Fund, less the value of fund distributions to date and the value of payments under the SEC settlement, is approximately $36 million. This amount does not take into account any assets remaining in the fund that may become available for future distributions.
	The Company is unable to predict the outcome or the timing of the ultimate resolution of the Ross lawsuit, or the potential loss, if any, that may result. However, management believes the outcome is not likely to have a material adverse effect on the financial condition, results of operations or cash flows of the Company.
	Other Legal and Regulatory Matters — The Company is subject to a number of other lawsuits, arbitrations, claims and other legal proceedings in connection with its business. Some of these legal actions include claims for substantial or unspecified compensatory and/or punitive damages. In addition, in the normal course of business, the Company discusses matters with its regulators raised during regulatory examinations or otherwise subject to their inquiry. These matters could result in censures, fines, penalties or other sanctions. ASC 450, Loss Contingencies, governs the recognition and disclosure of loss contingencies, including potential losses from legal and regulatory matters. ASC 450 categorizes loss contingencies using three terms based on the likelihood of occurrence of events that result in a loss: “probable” means that “the future event or events are likely to occur;” “remote” means that “the chance of the future event or events occurring is slight;” “and “reasonably possible” means that “the chance of the future event or events occurring is more than remote but less than likely.” Under ASC 450, the Company accrues for losses that are considered both probable and reasonably estimable. The Company may incur losses in addition to the amounts accrued where the losses are greater than estimated by management, or for matters for which an unfavorable outcome is considered reasonably possible, but not probable.
	The Company estimates that the aggregate range of reasonably possible losses in excess of amounts accrued is from $0 to $50 million as of September 30, 2013. This estimated aggregate range of reasonably possible losses is based upon currently available information for those legal and regulatory matters in which the Company is involved, taking into account the Company’s best estimate of reasonably possible losses for those cases as to which an estimate can be made. For certain cases, the Company does not believe an estimate can currently be made, as some cases are in preliminary stages and some cases have no specific amounts claimed. The Company’s estimate involves significant judgment, given the varying stages of the proceedings and the inherent uncertainty of predicting outcomes. The estimated range will change from time to time as the underlying matters, stages of proceedings and available information change. Actual losses may vary significantly from the current estimated range.
	The Company believes, based on its current knowledge and after consultation with counsel, that the ultimate disposition of these legal and regulatory matters, individually or in the aggregate, is not likely to have a material adverse effect on the financial condition or cash flows of the Company. However, in light of the uncertainties involved in such matters, the Company is unable to predict the outcome or the timing of the ultimate resolution of these matters, or the potential losses, fines, penalties or equitable relief, if any, that may result, and it is possible that the ultimate resolution of one or more of these matters may be material to the Company’s results of operations for a particular reporting period.
	Income Taxes — The Company’s federal and state income tax returns are subject to examination by taxing authorities. Because the application of tax laws and regulations to many types of transactions is subject to varying interpretations, amounts reported in the consolidated financial statements could be significantly changed at a later date upon final determinations by taxing authorities. TD has agreed to indemnify the Company for tax obligations, if any, pertaining to activities of TD Waterhouse Group, Inc. (“TD Waterhouse”) prior to the Company’s acquisition of TD Waterhouse in January 2006.
	General Contingencies — In the ordinary course of business, there are various contingencies that are not reflected in the consolidated financial statements. These include the Company’s broker-dealer subsidiaries’ client activities involving the execution, settlement and financing of various client securities, options, futures and foreign exchange transactions. These activities may expose the Company to credit risk in the event the clients are unable to fulfill their contractual obligations.
	The Company extends margin credit and leverage to its clients. In margin transactions, the Company extends credit to the client, subject to various regulatory and internal margin requirements, collateralized by cash and securities in the client’s account. In connection with these activities, the Company also executes and clears client transactions involving the sale of securities not yet purchased (“short sales”). Such margin-related transactions may expose the Company to credit risk in the event a client’s assets are not sufficient to fully cover losses that the client may incur. Leverage involves securing a large potential future obligation with a lesser amount of cash and securities. The risks associated with margin credit and leverage increase during periods of rapid market movements, or in cases where leverage or collateral is concentrated and market movements occur. In the event the client fails to satisfy its obligations, the Company has the authority to purchase or sell financial instruments in the client’s account at prevailing market prices in order to fulfill the client’s obligations. However, during periods of rapid market movements, clients who utilize margin credit or leverage and who have collateralized their obligations with securities may find that the securities have a rapidly depreciating value and may not be sufficient to cover their obligations in the event of liquidation. The Company seeks to mitigate the risks associated with its client margin and leverage activities by requiring clients to maintain margin collateral in compliance with various regulatory and internal guidelines. The Company monitors required margin levels throughout each trading day and, pursuant to such guidelines, requires clients to deposit additional collateral, or to reduce positions, when necessary.
	The Company loans securities temporarily to other broker-dealers in connection with its broker-dealer business. The Company receives cash as collateral for the securities loaned. Increases in securities prices may cause the market value of the securities loaned to exceed the amount of cash received as collateral. In the event the counterparty to these transactions does not return the loaned securities, the Company may be exposed to the risk of acquiring the securities at prevailing market prices in order to satisfy its client obligations. The Company mitigates this risk by requiring credit approvals for counterparties, by monitoring the market value of securities loaned on a daily basis and requiring additional cash as collateral when necessary, and by participating in a risk-sharing program offered through the Options Clearing Corporation (“OCC”).
	The Company borrows securities temporarily from other broker-dealers in connection with its broker-dealer business. The Company deposits cash as collateral for the securities borrowed. Decreases in securities prices may cause the market value of the securities borrowed to fall below the amount of cash deposited as collateral. In the event the counterparty to these transactions does not return the cash deposited, the Company may be exposed to the risk of selling the securities at prevailing market prices. The Company mitigates this risk by requiring credit approvals for counterparties, by monitoring the collateral values on a daily basis and requiring collateral to be returned by the counterparties when necessary, and by participating in a risk-sharing program offered through the OCC.
	The Company transacts in reverse repurchase agreements (securities purchased under agreements to resell) in connection with its broker-dealer business. The Company’s policy is to take possession or control of securities with a market value in excess of the principal amount loaned, plus accrued interest, in order to collateralize resale agreements. The Company monitors the market value of the underlying securities that collateralize the related receivable on resale agreements on a daily basis and may require additional collateral when deemed appropriate.
	The following table summarizes the fair values of client margin securities and stock borrowings that were available to the Company to utilize as collateral on various borrowings or for other purposes, and the amount of that collateral loaned or repledged by the Company (dollars in billions):
			September 30,
			2013		2012
	Client margin securities		$	12.5	$	12
	Stock borrowings			1.2		0.9
	Total collateral available		$	13.7	$	12.9
	Collateral loaned		$	1.9	$	1.9
	Collateral repledged			1.8		1.2
	Total collateral loaned or repledged		$	3.7	$	3.1
	The Company is subject to cash deposit and collateral requirements with clearinghouses based on its clients’ trading activity. The following table summarizes cash deposited with and securities pledged to clearinghouses by the Company (dollars in millions):
			September 30,
			2013		2012
	Cash		$	115	$	121
	U.S. government debt securities			61		56
	Total		$	176	$	177
	Guarantees — The Company is a member of and provides guarantees to securities clearinghouses and exchanges in connection with client trading activities. Under related agreements, the Company is generally required to guarantee the performance of other members. Under these agreements, if a member becomes unable to satisfy its obligations to the clearinghouse, other members would be required to meet shortfalls. The Company’s liability under these arrangements is not quantifiable and could exceed the cash and securities it has posted to the clearinghouse as collateral. However, the potential for the Company to be required to make payments under these agreements is considered remote. Accordingly, no contingent liability is carried on the Consolidated Balance Sheets for these guarantees.
	The Company clears its clients’ futures transactions on an omnibus account basis through an unaffiliated clearing firm. The Company has agreed to indemnify the unaffiliated clearing firm for any loss that it may incur for the client transactions introduced to it by the Company.
	See “Insured Deposit Account Agreement” in Note 19 for a description of a guarantee included in that agreement.
	Employment Agreements — The Company has entered into employment agreements with several of its key executive officers. These employment agreements generally provide for annual base salary and incentive compensation, as well as stock award acceleration and severance payments in the event of termination of employment under certain defined circumstances or changes in control of the Company. Incentive compensation, a portion of which is awarded in the form of stock-based compensation, is based on the Company’s financial performance and other factors.

Fair_Value_Disclosures

Fair Value Disclosures	12 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Disclosures	'
	16	Fair Value Disclosures
	Fair Value Measurement — Definition and Hierarchy
	ASC 820-10, Fair Value Measurement, defines fair value as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the measurement date.
	ASC 820-10 establishes a hierarchy for inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the most observable inputs be used when available. Observable inputs reflect the assumptions market participants would use in pricing the asset or liability, developed based on market data obtained from sources independent of the Company. Unobservable inputs reflect the Company’s own assumptions about the assumptions market participants would use in pricing the asset or liability, developed based on the best information available in the circumstances.
	The fair value hierarchy prioritizes the inputs to valuation techniques used to measure fair value into three broad levels, as follows:
		•		Level 1 — Quoted prices (unadjusted) in active markets for identical assets or liabilities that the Company has the ability to access. This category includes active exchange-traded funds, money market mutual funds, mutual funds and equity securities.
		•		Level 2 — Inputs other than quoted prices included in Level 1 that are observable for the asset or liability, either directly or indirectly. Such inputs include quoted prices in markets that are not active, quoted prices for similar assets and liabilities in active and inactive markets, inputs other than quoted prices that are observable for the asset or liability and inputs that are derived principally from or corroborated by observable market data by correlation or other means. This category includes most debt securities and other interest-sensitive financial instruments. This category also includes convertible preferred equity securities for which the fair value was measured on an as-converted basis.
		•		Level 3 — Unobservable inputs for the asset or liability, where there is little, if any, observable market activity or data for the asset or liability. This category includes assets and liabilities related to money market and other mutual funds managed by The Reserve for which the net asset value has declined below $1.00 per share and the funds are being liquidated. This category also includes auction rate securities for which the periodic auctions have failed.
	The following tables present the Company’s fair value hierarchy for assets and liabilities measured at fair value on a recurring basis as of September 30, 2013 and 2012 (dollars in millions):
			As of September 30, 2013
			Level 1			Level 2			Level 3			Fair Value
	Assets:
	Cash equivalents:
	Money market mutual funds		$	969		$	—		$	—		$	969
	Short-term investments available-for-sale:
	U.S. government debt securities			—			4			—			4
	Investments segregated for regulatory purposes:
	U.S. government debt securities			—			2,045			—			2,045
	Securities owned:
	Auction rate securities			—			—			5			5
	Money market and other mutual funds			—			—			1			1
	U.S. government debt securities			—			313			—			313
	Other			1			3			—			4
	Subtotal — Securities owned			1			316			6			323
	Investments available-for-sale:
	Equity securities			13			—			—			13
	Other assets:
	Interest rate swaps(1)			—			52			—			52
	Total assets at fair value		$	983		$	2,417		$	6		$	3,406
	Liabilities:
	Accounts payable and accrued liabilities:
	Securities sold, not yet purchased:
	Equity securities		$	13		$	—		$	—		$	13
	-1	See “Interest Rate Swaps” in Note 9 for details.
			As of September 30, 2012
			Level 1			Level 2			Level 3			Fair Value
	Assets:
	Cash equivalents:
	Money market mutual funds		$	768		$	—		$	—		$	768
	U.S. government debt securities			—			50			—			50
	Subtotal — Cash equivalents			768			50			—			818
	Short-term investments available-for-sale:
	U.S. government debt securities			—			154			—			154
	Investments segregated for regulatory purposes:
	U.S. government debt securities			—			1,574			—			1,574
	Securities owned:
	Auction rate securities			—			—			6			6
	Money market and other mutual funds			—			—			1			1
	U.S. government debt securities			—			333			—			333
	Other			1			2			—			3
	Subtotal—Securities owned			1			335			7			343
	Investments available-for-sale:
	Convertible preferred equity securities			—			70			—			70
	Other assets:
	Interest rate swaps(1)			—			96			—			96
	Total assets at fair value		$	769		$	2,279		$	7		$	3,055
	Liabilities:
	Accounts payable and accrued liabilities:
	Securities sold, not yet purchased:
	Equity securities		$	3		$	—		$	—		$	3
	-1	See “Interest Rate Swaps” in Note 9 for details.
	There were no transfers between any levels of the fair value hierarchy during the periods presented in the tables below. The following tables present the changes in Level 3 assets measured at fair value on a recurring basis for the fiscal years ended September 30, 2013, 2012 and 2011 (dollars in millions):
			Year Ended September 30,
		2013						2012
		Auction Rate			Money Market			Auction Rate			Money Market
		Securities			and Other			Securities			and Other
					Mutual Funds						Mutual Funds
Balance, beginning of year		$	6		$	1		$	20		$	1
Purchases			—			—			1			—
Sales			—			—			(2	)		—
Settlements			(1	)		—			(13	)		—
Balance, end of year		$	5		$	1		$	6		$	1
		Year Ended September 30, 2011
		Auction Rate			Money Market
		Securities			and Other
					Mutual Funds
Balance, beginning of year		$	209		$	5
Net gains included in earnings			5	(1)		—
Purchases, sales, issuances and settlements, net			(194	)		(4	)
Balance, end of year		$	20		$	1
-1	Net gains on auction rate securities are recorded in other revenues on the Consolidated Statements of Income. For the year ended September 30, 2011, substantially all of the net gains on auction rate securities related to assets not held as of September 30, 2011.
Valuation Techniques
In general, and where applicable, the Company uses quoted prices in active markets for identical assets or liabilities to determine fair value. This pricing methodology applies to the Company’s Level 1 assets and liabilities. If quoted prices in active markets for identical assets and liabilities are not available to determine fair value, then the Company uses quoted prices for similar assets and liabilities or inputs other than the quoted prices that are observable, either directly or indirectly. This pricing methodology applies to the Company’s Level 2 assets and liabilities.
Level 2 Measurements:
Convertible Preferred Equity Securities — These securities represented the Company’s investment in 39,000 shares of Knight Capital Group, Inc. 2% convertible preferred shares. Each preferred share was convertible to 666.667 shares of Knight Class A common stock. The fair value of the preferred securities was based on quoted market prices of Knight Class A common stock on an as-converted basis.
Debt Securities — Fair values for debt securities are based on prices obtained from an independent pricing vendor. The primary inputs to the valuation include quoted prices for similar assets in active markets, quoted prices for identical or similar assets in markets that are not active, contractual cash flows, benchmark yields and credit spreads. The Company validates the vendor pricing by periodically comparing it to pricing from another independent pricing service. The Company has not adjusted prices obtained from the independent pricing vendor for any periods presented in the Consolidated Financial Statements because no significant pricing differences have been observed.
Interest Rate Swaps — These derivatives are valued by the Company using a valuation model provided by a third party service that incorporates interest rate yield curves, which are observable for substantially the full term of the contract. The valuation model is widely accepted in the financial services industry and does not involve significant judgment because most of the inputs are observable in the marketplace. Counterparty credit risk is not an input to the valuation because the Company has possession of collateral, in the form of cash or U.S. Treasury securities, in amounts equal to or exceeding the fair value of the interest rate swaps. The Company validates the third party service valuations by comparing them to valuation models provided by the swap counterparties.
Level 3 Measurements:
Money Market and Other Mutual Funds — The fair value of positions in money market and other mutual funds managed by The Reserve is estimated by management based on the underlying portfolio holdings data published by The Reserve.
Auction Rate Securities (“ARS”) — ARS are long-term variable rate securities tied to short-term interest rates that are reset through a “Dutch auction” process, which generally occurs every seven to 35 days. Holders of ARS were previously able to liquidate their holdings to prospective buyers by participating in the auctions. During fiscal 2008, the Dutch auction process failed and holders were no longer able to liquidate their holdings through the auction process. The fair value of Company ARS holdings is primarily estimated based on an internal pricing model. The pricing model takes into consideration the characteristics of the underlying securities, as well as multiple inputs, including counterparty credit quality, expected timing of redemptions and an estimated yield premium that a market participant would require over otherwise comparable securities to compensate for the illiquidity of the ARS. These inputs require significant management judgment.
The following tables summarize quantitative information about Level 3 unobservable inputs as of September 30, 2013 and 2012:
As of September 30, 2013
Asset		Valuation		Unobservable	Range		Weighted
		Technique		Input			Average
Auction Rate Securities		Discounted		Constant	10% - 20%		15%
		cash flow		prepayment rate
				(Annual)
				Yield premium for	2%		2%
				illiquidity
As of September 30, 2012
Asset		Valuation		Unobservable	Range		Weighted
		Technique		Input			Average
Auction Rate Securities		Discounted		Constant	15% - 20%		17%
		cash flow		prepayment rate
				(Annual)
				Yield premium for	2%		2%
				illiquidity
Fair Value of Financial Instruments Not Recorded at Fair Value
Cash and cash equivalents, receivable from/payable to brokers, dealers and clearing organizations, receivable from/payable to clients, receivable from/payable to affiliates, other receivables and accounts payable and accrued liabilities are short-term in nature and accordingly are carried at amounts that approximate fair value. Cash and cash equivalents include cash and highly-liquid investments with an original maturity of three months or less (categorized as Level 1 of the fair value hierarchy). Receivable from/payable to brokers, dealers and clearing organizations, receivable from/payable to clients, receivable from/payable to affiliates, other receivables and accounts payable and accrued liabilities are recorded at or near their respective transaction prices and historically have been settled or converted to cash at approximately that value (categorized as Level 2 of the fair value hierarchy).
Cash and investments segregated and on deposit for regulatory purposes includes reverse repurchase agreements (securities purchased under agreements to resell). Reverse repurchase agreements are treated as collateralized financing transactions and are carried at amounts at which the securities will subsequently be resold, plus accrued interest. The Company’s reverse repurchase agreements generally have a maturity of seven days and are collateralized by U.S. Treasury securities in amounts exceeding the carrying value of the resale agreements. Accordingly, the carrying value of reverse repurchase agreements approximates fair value (categorized as Level 2 of the fair value hierarchy). In addition, this category includes cash held in demand deposit accounts and on deposit with a futures commission merchant, for which the carrying values approximate the fair value (categorized as Level 1 of the fair value hierarchy). See Note 4 for a summary of cash and investments segregated and on deposit for regulatory purposes.
Senior Notes — As of September 30, 2013, the Company’s Senior Notes had an aggregate estimated fair value, based on quoted market prices (categorized as Level 1 of the fair value hierarchy), of approximately $1.100 billion, compared to the aggregate carrying value of the Senior Notes on the Consolidated Balance Sheet of $1.052 billion. As of September 30, 2012, the Company’s Senior Notes had an aggregate estimated fair value, based on quoted market prices, of approximately $1.373 billion, compared to the aggregate carrying value of the Senior Notes on the Consolidated Balance Sheet of $1.345 billion.

Segment_and_Geographic_Area_In

Segment and Geographic Area Information	12 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Segment and Geographic Area Information	'
	17	Segment and Geographic Area Information
	The Company primarily operates in the securities brokerage industry and has no other reportable segments. Substantially all of the Company’s revenues from external clients for the fiscal years ended September 30, 2013, 2012 and 2011 were derived from its operations in the United States.

Structured_Stock_Repurchase

Structured Stock Repurchase	12 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Structured Stock Repurchase	'
	18	Structured Stock Repurchase
	On August 20, 2010, the Company entered into an agreement with an investment bank counterparty to effect a structured repurchase of up to 12 million shares of its common stock. The Company entered into this structured stock repurchase agreement in order to lower the average cost of acquiring shares of its common stock. The Company evaluated the contingent exercise provisions and settlement provisions of the agreement, as well as all other conditions for equity accounting under ASC 815-40, Contracts in Entity’s Own Equity, and determined that the agreement qualified for treatment as an equity instrument. Under the terms of the agreement, the Company prepaid $169 million to the counterparty, which was recorded as a reduction of additional paid-in capital on the Consolidated Balance Sheet. Settlement of the transaction occurred on December 1, 2010 and the Company purchased approximately 3.2 million shares for approximately $50 million ($15.94 per share). The number of shares the Company purchased from the counterparty and the purchase price were based on the average of the daily volume-weighted average share price of the Company’s common stock over the measurement period for the transaction, less a pre-determined discount. Upon settlement of the transaction, the Company was entitled to receive the excess prepayment amount of $119 million in the form of cash or shares, at the Company’s option. The Company elected to receive cash, which was recorded as additional paid-in capital.

Related_Party_Transactions

Related Party Transactions	12 Months Ended
	Sep. 30, 2013
Related Party Transactions [Abstract]	'
Related Party Transactions	'
	19	Related Party Transactions
	Transactions with TD and Affiliates
	As a result of the Company’s acquisition of TD Waterhouse during fiscal 2006, TD became an affiliate of the Company. TD owned approximately 42% of the Company’s common stock as of September 30, 2013. Pursuant to the Stockholders Agreement among TD, the Company and certain other stockholders, TD has the right to designate five of twelve members of the Company’s board of directors. The Company transacts business and has extensive relationships with TD and certain of its affiliates. Transactions with TD and its affiliates are discussed and summarized below.
	Insured Deposit Account Agreement
	Through December 31, 2012, the Company was party to an insured deposit account (“IDA”) agreement, dated as of December 19, 2009, with TD Bank USA, N.A. (“TD Bank USA”), TD Bank, N.A. and TD (the “old IDA agreement”). Under the old IDA agreement, TD Bank USA and TD Bank, N.A. (together, the “Depository Institutions”) made available to clients of the Company FDIC-insured money market deposit accounts as either designated sweep vehicles or as non-sweep deposit accounts. The Company provided marketing, recordkeeping and support services for the Depository Institutions with respect to the money market deposit accounts. In exchange for providing these services, the Depository Institutions paid the Company an aggregate marketing fee based on the weighted average yield earned on the client IDA assets, less the actual interest paid to clients, a flat servicing fee to the Depository Institutions of 25 basis points and the cost of FDIC insurance premiums.
	The fee earned on the old IDA agreement was calculated based on two primary components: (a) the yield on fixed-rate “notional” investments, based on prevailing fixed rates for identical balances and maturities in the interest rate swap market (generally LIBOR-based) at the time such investments were added to the IDA portfolio (including any adjustments required to adjust the variable rate leg of such swaps to a one-month reset frequency and the overall swap payment frequency to monthly) and (b) the yield on floating-rate investments, based on the monthly average rate for 30-day LIBOR. The agreement provided that, from time to time, the Company may request amounts and maturity dates for the fixed-rate notional investments in the IDA portfolio, subject to the approval of the Depository Institutions. For example, if the Company requested (and the Depository Institutions agreed) that $100 million of deposits should be invested in 5-year fixed-rate investments, and on the day such investment was approved the prevailing fixed yield for the applicable 5-year U.S. dollar LIBOR-based swaps was 1.00%, then the Company would earn a gross fixed yield of 1.00% on that portion of the portfolio (before any deductions for interest paid to clients, the flat 25 basis point servicing fee to the Depository Institutions and the cost of FDIC insurance premiums). The interest rates paid to clients were set by the Depository Institutions and were not linked to any index.
	On January 17, 2013, the Company entered into a new IDA agreement among the same parties (the “new IDA agreement”), which superseded and replaced the old IDA agreement. The new IDA agreement became effective as of January 1, 2013 and has an initial term expiring July 1, 2018. It is automatically renewable for successive five-year terms, provided that it may be terminated by either the Company or the Depository Institutions by providing written notice of non-renewal at least two years prior to the initial expiration date or the expiration date of any subsequent renewal period. The marketing fee calculation under the new IDA agreement is substantially similar to the old IDA agreement, with certain significant differences described below.
	The new IDA agreement provides that the Company may designate amounts and maturity dates for the fixed-rate notional investments in the IDA portfolio, subject to certain limitations. In the event that (1) the federal funds effective rate is established at 0.75% or greater and (2) the rate on 5-year U.S. dollar interest rate swaps is equal to or greater than 1.50% for 20 consecutive business days, then the rate earned by the Company on new fixed-rate notional investments will be reduced by 20% of the excess of the 5-year U.S. dollar swap rate over 1.50%, up to a maximum of 0.10%.
	Under the new IDA agreement, the yield on floating-rate investments is calculated daily based on the greater of the following rates published by the Federal Reserve: (1) the interest rate paid by Federal Reserve Banks on balances held in excess of required reserve balances and contractual clearing balances under Regulation D and (2) the daily effective federal funds rate.
	As of September 30, 2013, the IDA portfolio was comprised of approximately 79% fixed-rate notional investments and 21% floating-rate investments.
	The servicing fee to the Depository Institutions under the new IDA agreement is equal to 25 basis points on the aggregate average daily balance in the IDA accounts, subject to adjustment as it relates to deposits of less than or equal to $20 billion kept in floating-rate investments or in fixed-rate notional investments with a maturity of up to 24 months (“short-term fixed-rate investments”). For floating-rate and short-term fixed-rate investments, the servicing fee is equal to the difference of the interest rate earned on the investments less the FDIC premiums paid (in basis points), divided by two. The servicing fee has a floor of 3 basis points (subject to adjustment from time to time to reflect material changes to the Depository Institutions’ leverage costs) and a maximum of 25 basis points.
	Under both the new and old IDA agreements, in the event the marketing fee computation results in a negative amount, the Company must pay the Depository Institutions the negative amount. This effectively results in the Company guaranteeing the Depository Institutions revenue equal to the servicing fee on the IDA agreement, plus the reimbursement of FDIC insurance premiums. The marketing fee computation under the IDA agreement is affected by many variables, including the type, duration, principal balance and yield of the fixed-rate and floating-rate investments, the prevailing interest rate environment, the amount of client deposits and the yield paid on client deposits. Because a negative marketing fee computation would arise only if there were extraordinary movements in many of these variables, the maximum potential amount of future payments the Company could be required to make under this arrangement cannot be reasonably estimated. Management believes the potential for the marketing fee calculation to result in a negative amount is remote. Accordingly, no contingent liability is carried on the Consolidated Balance Sheets for the IDA agreement.
	In addition, the Company has various other services agreements and transactions with TD and its affiliates. The following tables summarize revenues and expenses resulting from transactions with TD and its affiliates for the fiscal years indicated (dollars in millions):
	Description		Statement of Income		Revenues from TD and Affiliates
			Classification		2013				2012		2011
	Insured Deposit Account Agreement		Insured deposit account fees		$	804			$	828	$	763
	Mutual Fund Agreements		Investment product fees			1				3		8
	Referral and Strategic Alliance Agreement		Various			11				8		4
	Securities borrowing and lending, net		Net interest revenue			2				3		4
	Other		Various			3				2		3
	Total revenues				$	821			$	844	$	782
	Description		Statement of Income		Expenses to TD and Affiliates
			Classification		2013				2012		2011
	Canadian Call Center Services Agreement		Professional Services		$	19			$	18	$	18
	Other		Various			4				4		4
	Total expenses				$	23			$	22	$	22
	The following table summarizes the classification and amount of receivables from and payables to TD and its affiliates on the Consolidated Balance Sheets resulting from related party transactions (dollars in millions):
			September 30,
			2013				2012
	Assets:
	Receivable from brokers, dealers and clearing organizations		$	1			$	1
	Receivable from affiliates			117				85
	Liabilities:
	Payable to brokers, dealers and clearing organizations		$	115			$	125
	Payable to affiliates			4				4
	Receivables from and payables to brokers, dealers and clearing organizations primarily relate to securities borrowing and lending activity and are settled in accordance with customary contractual terms. Receivables from and payables to TD affiliates resulting from client cash sweep activity are generally settled in cash the next business day. Other receivables from and payables to affiliates of TD are generally settled in cash on a monthly basis.

Condensed_Consolidating_Financ

Condensed Consolidating Financial Information	12 Months Ended
	Sep. 30, 2013
Organization Consolidation And Presentation Of Financial Statements [Abstract]	'
Condensed Consolidating Financial Information	'
	20	Condensed Consolidating Financial Information
	The Senior Notes are jointly and severally and fully and unconditionally guaranteed by TDAOH. Presented below is condensed consolidating financial information for the Company, its guarantor subsidiary and its non-guarantor subsidiaries for the periods indicated. Because all other comprehensive income (loss) activity occurred on the parent company for all periods presented, condensed consolidating statements of comprehensive income are not presented.
	CONDENSED CONSOLIDATING BALANCE SHEET
	As of September 30, 2013
			Parent			Guarantor			Non-Guarantor			Eliminations			Total
						Subsidiary			Subsidiaries
			(In millions)
	ASSETS
	Cash and cash equivalents		$	199		$	7		$	856		$	—		$	1,062
	Short-term investments available-for-sale			—			—			4			—			4
	Cash and investments segregated and on deposit for regulatory purposes			—			—			5,894			—			5,894
	Receivable from brokers, dealers and clearing organizations			—			—			1,348			—			1,348
	Receivable from clients, net			—			—			8,984			—			8,984
	Investments in subsidiaries			5,568			5,360			550			(11,478	)		—
	Receivable from affiliates			4			3			117			(7	)		117
	Goodwill			—			—			2,467			—			2,467
	Acquired intangible assets, net			—			146			695			—			841
	Other, net			140			9			1,011			(41	)		1,119
	Total assets		$	5,911		$	5,525		$	21,926		$	(11,526	)	$	21,836
	LIABILITIES AND STOCKHOLDERS’ EQUITY
	Liabilities:
	Payable to brokers, dealers and clearing organizations		$	—		$	—		$	1,973		$	—		$	1,973
	Payable to clients			—			—			13,183			—			13,183
	Accounts payable and accrued liabilities			180			—			410			(8	)		582
	Payable to affiliates			3			—			8			(7	)		4
	Long-term debt			1,052			—			—			—			1,052
	Other			—			51			348			(33	)		366
	Total liabilities			1,235			51			15,922			(48	)		17,160
	Stockholders’ equity			4,676			5,474			6,004			(11,478	)		4,676
	Total liabilities and stockholders’ equity		$	5,911		$	5,525		$	21,926		$	(11,526	)	$	21,836
	CONDENSED CONSOLIDATING BALANCE SHEET
	As of September 30, 2012
			Parent			Guarantor			Non-Guarantor			Eliminations			Total
						Subsidiary			Subsidiaries
			(In millions)
	ASSETS
	Cash and cash equivalents		$	178		$	6		$	731		$	—		$	915
	Short-term investments available-for-sale			151			—			3			—			154
	Cash and investments segregated and on deposit for regulatory purposes			—			—			4,030			—			4,030
	Receivable from brokers, dealers and clearing organizations			—			—			1,110			—			1,110
	Receivable from clients, net			—			—			8,647			—			8,647
	Investments in subsidiaries			5,456			5,250			548			(11,254	)		—
	Receivable from affiliates			5			3			83			(6	)		85
	Goodwill			—			—			2,467			—			2,467
	Acquired intangible assets, net			—			146			786			—			932
	Other, net			230			7			961			(25	)		1,173
	Total assets		$	6,020		$	5,412		$	19,366		$	(11,285	)	$	19,513
	LIABILITIES AND STOCKHOLDERS’ EQUITY
	Liabilities:
	Payable to brokers, dealers and clearing organizations		$	—		$	—		$	1,992		$	—		$	1,992
	Payable to clients			—			—			10,728			—			10,728
	Accounts payable and accrued liabilities			249			—			391			(8	)		632
	Payable to affiliates			1			—			9			(6	)		4
	Long-term debt			1,345			—			—			—			1,345
	Other			—			48			356			(17	)		387
	Total liabilities			1,595			48			13,476			(31	)		15,088
	Stockholders’ equity			4,425			5,364			5,890			(11,254	)		4,425
	Total liabilities and stockholders’ equity		$	6,020		$	5,412		$	19,366		$	(11,285	)	$	19,513
	CONDENSED CONSOLIDATING STATEMENT OF INCOME
	For the Year Ended September 30, 2013
			Parent			Guarantor			Non-Guarantor			Eliminations			Total
						Subsidiary			Subsidiaries
			(In millions)
Net revenues		$	12		$	—		$	2,763		$	(11	)	$	2,764
Operating expenses			10			—			1,709			(11	)		1,708
Operating income			2			—			1,054			—			1,056
Other income			(23	)		—			(9	)		—			(32	)
Income before income taxes and equity in income of subsidiaries			25			—			1,063			—			1,088
Provision for income taxes			8			—			405			—			413
Income before equity in income of subsidiaries			17			—			658			—			675
Equity in income of subsidiaries			658			634			36			(1,328	)		—
Net income		$	675		$	634		$	694		$	(1,328	)	$	675
CONDENSED CONSOLIDATING STATEMENT OF INCOME
For the Year Ended September 30, 2012
		Parent			Guarantor			Non-Guarantor			Eliminations			Total
					Subsidiary			Subsidiaries
		(In millions)
Net revenues		$	32		$	—		$	2,641		$	(32	)	$	2,641
Operating expenses			28			—			1,711			(32	)		1,707
Operating income			4			—			930			—			934
Other expense (income)			29			—			(1	)		—			28
Income (loss) before income taxes and equity in income of subsidiaries			(25	)		—			931			—			906
Provision for (benefit from) income taxes			(19	)		(3	)		342			—			320
Income (loss) before equity in income of subsidiaries			(6	)		3			589			—			586
Equity in income of subsidiaries			592			577			33			(1,202	)		—
Net income		$	586		$	580		$	622		$	(1,202	)	$	586
CONDENSED CONSOLIDATING STATEMENT OF INCOME
For the Year Ended September 30, 2011
		Parent			Guarantor			Non-Guarantor			Eliminations			Total
					Subsidiary			Subsidiaries
		(In millions)
Net revenues		$	17		$	—		$	2,763		$	(17	)	$	2,763
Operating expenses			16			—			1,716			(17	)		1,715
Operating income			1			—			1,047			—			1,048
Other expense (income)			33			—			(2	)		—			31
Income (loss) before income taxes and equity in income of subsidiaries			(32	)		—			1,049			—			1,017
Provision for (benefit from) income taxes			(13	)		(1	)		393			—			379
Income (loss) before equity in income of subsidiaries			(19	)		1			656			—			638
Equity in income of subsidiaries			657			673			38			(1,368	)		—
Net income		$	638		$	674		$	694		$	(1,368	)	$	638
CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
For the Year Ended September 30, 2013
		Parent			Guarantor			Non-Guarantor			Total
					Subsidiary			Subsidiaries
		(In millions)
Net cash provided by (used in) operating activities		$	(70	)	$	1		$	808		$	739
Cash flows from investing activities:
Purchase of property and equipment			—			—			(144	)		(144	)
Proceeds from sale and maturity of short-term investments			150			—			4			154
Purchase of short-term investments			—			—			(4	)		(4	)
Proceeds from sale of investments			78			—			10			88
Other, net			—			—			2			2
Net cash provided by (used in) investing activities			228			—			(132	)		96
Cash flows from financing activities:
Principal payments on long-term debt			(250	)		—			—			(250	)
Proceeds from notes payable			275			—			—			275
Principal payments on notes payable			(275	)		—			—			(275	)
Payment of cash dividends			(471	)		—			—			(471	)
Purchase of treasury stock			(5	)		—			—			(5	)
Other, net			43			—			(5	)		38
Net cash used in financing activities			(683	)		—			(5	)		(688	)
Intercompany investing and financing activities, net			546			—			(546	)		—
Net increase in cash and cash equivalents			21			1			125			147
Cash and cash equivalents at beginning of year			178			6			731			915
Cash and cash equivalents at end of year		$	199		$	7		$	856		$	1,062
CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
For the Year Ended September 30, 2012
		Parent			Guarantor			Non-Guarantor			Total
					Subsidiary			Subsidiaries
		(In millions)
Net cash provided by operating activities		$	46		$	2		$	544		$	592
Cash flows from investing activities:
Purchase of property and equipment			—			—			(186	)		(186	)
Purchase of short-term investments			(152	)		—			(3	)		(155	)
Purchase of investments			(43	)		—			(1	)		(44	)
Proceeds from sale of investments			2			—			—			2
Proceeds from sale and maturity of short-term investments			—			—			4			4
Other, net			—			—			2			2
Net cash used in investing activities			(193	)		—			(184	)		(377	)
Cash flows from financing activities:
Purchase of treasury stock			(208	)		—			—			(208	)
Payment of cash dividends			(132	)		—			—			(132	)
Other, net			4			—			4			8
Net cash provided by (used in) financing activities			(336	)		—			4			(332	)
Intercompany investing and financing activities, net			567			(3	)		(564	)		—
Net increase (decrease) in cash and cash equivalents			84			(1	)		(200	)		(117	)
Cash and cash equivalents at beginning of year			94			7			931			1,032
Cash and cash equivalents at end of year		$	178		$	6		$	731		$	915
CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
For the Year Ended September 30, 2011
					Guarantor			Non-Guarantor
		Parent			Subsidiary			Subsidiaries			Total
		(In millions)
Net cash provided by (used in) operating activities		$	(45	)	$	202		$	633		$	790
Cash flows from investing activities:
Purchase of property and equipment			—			—			(153	)		(153	)
Purchase of short-term investments			—			—			(4	)		(4	)
Purchase of investments			—			—			(5	)		(5	)
Proceeds from sale of investments			—			—			3			3
Proceeds from sale and maturity of short-term investments			—			—			4			4
Other, net			—			—			3			3
Net cash used in investing activities			—			—			(152	)		(152	)
Cash flows from financing activities:
Principal payments on long-term debt			—			—			(4	)		(4	)
Purchase of treasury stock			(349	)		—			—			(349	)
Return of prepayment on structured stock repurchase			119			—			—			119
Payment of cash dividends			(114	)		—			—			(114	)
Other, net			13			—			(12	)		1
Net cash used in financing activities			(331	)		—			(16	)		(347	)
Intercompany investing and financing activities, net			403			(220	)		(183	)		—
Net increase (decrease) in cash and cash equivalents			27			(18	)		282			291
Cash and cash equivalents at beginning of year			67			25			649			741
Cash and cash equivalents at end of year		$	94		$	7		$	931		$	1,032

Quarterly_Data_Unaudited

Quarterly Data (Unaudited)	12 Months Ended
	Sep. 30, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Quarterly Data (Unaudited)	'
	21	Quarterly Data (Unaudited)
	(Dollars in millions, except per share amounts)
			For the Fiscal Year Ended September 30, 2013
			First		Second		Third		Fourth
			Quarter		Quarter		Quarter		Quarter(1)
	Net revenues		$	651	$	679	$	725	$	709
	Operating income		$	241	$	237	$	298	$	279
	Net income		$	147	$	144	$	184	$	200
	Basic earnings per share		$	0.27	$	0.26	$	0.33	$	0.36
	Diluted earnings per share		$	0.27	$	0.26	$	0.33	$	0.36
			For the Fiscal Year Ended September 30, 2012
			First		Second		Third		Fourth
			Quarter		Quarter		Quarter		Quarter
	Net revenues		$	653	$	673	$	667	$	647
	Operating income		$	228	$	219	$	254	$	232
	Net income		$	152	$	137	$	154	$	143
	Basic earnings per share		$	0.28	$	0.25	$	0.28	$	0.26
	Diluted earnings per share		$	0.27	$	0.25	$	0.28	$	0.26
	Quarterly amounts may not sum to fiscal year totals due to rounding.
		-1	The Company’s results of operations for the fourth quarter of fiscal 2013 include a pre-tax gain of $54 million ($34 million after tax, or $0.06 per diluted share) in connection with Knight Capital Group, Inc.’s July 1, 2013 merger with GETCO Holding Company, LLC. For more information regarding the Knight-GETCO merger, see Note 7.

Nature_of_Operations_and_Summa1

Nature of Operations and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Sep. 30, 2013
Accounting Policies [Abstract]	'
Basis of Presentation	'
	Basis of Presentation — The consolidated financial statements include the accounts of TD Ameritrade Holding Corporation, a Delaware corporation, and its wholly-owned subsidiaries (collectively, the “Company”). Intercompany balances and transactions have been eliminated.
Nature of Operations	'
	Nature of Operations — The Company provides securities brokerage services, including trade execution, clearing services and margin lending, through its broker-dealer subsidiaries. The Company provides trustee, custodial and other trust-related services to retirement plans and other custodial accounts through its state-chartered trust company subsidiary. The Company’s education subsidiary provides a comprehensive suite of investor education products and services. The Company also provides cash sweep and deposit account products through third-party relationships.
	The Company’s broker-dealer subsidiaries are subject to regulation by the Securities and Exchange Commission (“SEC”), the Financial Industry Regulatory Authority (“FINRA”), the Commodity Futures Trading Commission (“CFTC”), the National Futures Association (“NFA”) and the various exchanges in which they maintain membership. Dividends from the Company’s broker-dealer and trust company subsidiaries are a source of liquidity for the holding company. Requirements of the SEC, FINRA and CFTC relating to liquidity, net capital standards and the use of client funds and securities may limit funds available for the payment of dividends from the broker-dealer subsidiaries to the holding company. State regulatory requirements may limit funds available for the payment of dividends from the trust company subsidiary to the holding company.
Use of Estimates	'
	Use of Estimates — The preparation of consolidated financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that affect the reported amount of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates.
Cash and Cash Equivalents	'
	Cash and Cash Equivalents — The Company considers temporary, highly-liquid investments with an original maturity of three months or less to be cash equivalents, except for amounts required to be segregated for regulatory purposes.
Cash and Investments Segregated and on Deposit for Regulatory Purposes	'
	Cash and Investments Segregated and on Deposit for Regulatory Purposes — Cash and investments segregated and on deposit for regulatory purposes consists primarily of qualified deposits in special reserve bank accounts for the exclusive benefit of clients under Rule 15c3-3 of the Securities Exchange Act of 1934 (the “Exchange Act”) and other regulations. Funds can be held in cash, reverse repurchase agreements, U.S. Treasury securities and other qualified securities. Reverse repurchase agreements (securities purchased under agreements to resell) are treated as collateralized financing transactions and are carried at amounts at which the securities will subsequently be resold, plus accrued interest. The Company’s reverse repurchase agreements are collateralized by U.S. Treasury securities and generally have a maturity of seven days. Cash and investments segregated and on deposit for regulatory purposes also includes amounts that have been segregated or secured for the benefit of futures clients according to the regulations of the CFTC governing futures commission merchants.
Securities Borrowed and Securities Loaned	'
	Securities Borrowed and Securities Loaned — Securities borrowed and securities loaned transactions are recorded at the amount of cash collateral advanced or received. Securities borrowed transactions require the Company to provide the counterparty with collateral in the form of cash. The Company receives collateral in the form of cash for securities loaned transactions. For these transactions, the fees earned or incurred by the Company are recognized in the period earned or incurred and recorded as interest revenue and brokerage interest expense, respectively, on the Consolidated Statements of Income. The related interest receivable from and the brokerage interest payable to broker-dealers are included in other receivables and in accounts payable and accrued liabilities, respectively, on the Consolidated Balance Sheets.
Receivable from/Payable to Clients	'
	Receivable from/Payable to Clients — Receivable from clients primarily consists of margin loans to securities brokerage clients, which are collateralized by client securities, and is carried at the amount receivable, net of an allowance for doubtful accounts that is primarily based on the amount of unsecured margin balances. Payable to clients primarily consists of client cash held in brokerage accounts and is carried at the amount of client cash on deposit. The Company earns interest revenue and pays interest expense on its receivable from client and payable to client balances, respectively. The interest revenue and expense are included in net interest revenue on the Consolidated Statements of Income.
Investments available for sale	'
	Investments available for sale — The Company’s investments in marketable securities are carried at fair value and are designated as available-for-sale, except for securities owned by the Company’s broker-dealer subsidiaries, which are accounted for as trading investments and are classified as securities owned on the Consolidated Balance Sheets. Unrealized gains and losses on available-for-sale investments, net of deferred income taxes, are reflected on the Consolidated Balance Sheets as a component of stockholders’ equity. Realized gains and losses on available-for-sale investments are determined on the specific identification method and are reflected on the Consolidated Statements of Income. Declines in fair value of investments that are considered other than temporary are accounted for as realized losses.
Securities Owned	'
	Securities Owned — Securities owned are recorded on a trade-date basis and carried at fair value, and the related changes in fair value are generally included in other revenues on the Consolidated Statements of Income. Securities held by our broker-dealer subsidiaries for trading or investment purposes are included in securities owned on the Consolidated Balance Sheets.
Property and Equipment	'
	Property and Equipment — Property and equipment is recorded at cost, net of accumulated depreciation and amortization, except for land, which is recorded at cost. Depreciation is provided using the straight-line method over the estimated useful service lives of the assets, which range from 10 to 40 years for building and building components and three to seven years for all other depreciable property and equipment. Leasehold improvements are amortized over the lesser of the economic useful life of the improvement or the term of the lease.
Software Development	'
	Software Development — From the date technological feasibility has been established until beta testing is complete, software development costs are capitalized and included in property and equipment. Once the product is fully functional, such costs are amortized in accordance with the Company’s normal accounting policies. Software development costs that do not meet capitalization criteria are expensed as incurred.
Goodwill	'
	Goodwill — The Company has recorded goodwill for purchase business combinations to the extent the purchase price of each completed acquisition exceeded the fair value of the net identifiable assets of the acquired company. The Company tests goodwill for impairment on at least an annual basis. In performing the impairment tests, the Company utilizes quoted market prices of the Company’s common stock to estimate the fair value of the Company as a whole. The estimated fair value is then allocated to the Company’s reporting units, if applicable, based on operating revenues, and is compared with the carrying value of the reporting units. No impairment charges have resulted from the annual impairment tests.
Amortization of Acquired Intangible Assets	'
	Amortization of Acquired Intangible Assets — Acquired intangible assets with finite lives are amortized on a straight-line basis over their estimated useful lives, ranging from three to 23 years. The acquired intangible asset associated with a trademark license agreement is not subject to amortization because the term of the agreement is considered to be indefinite.
Long-Lived Assets and Acquired Intangible Assets	'
	Long-Lived Assets and Acquired Intangible Assets — The Company reviews its long-lived assets and finite-lived acquired intangible assets for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. The Company evaluates recoverability by comparing the undiscounted cash flows associated with the asset to the asset’s carrying amount. Long-lived assets classified as “held for sale,” if any, are reported at the lesser of carrying amount or fair value less cost to sell.
	The Company tests its indefinite-lived acquired intangible asset for impairment on at least an annual basis. To determine if the indefinite-lived intangible asset is impaired, the Company first assesses certain qualitative factors. Based on this assessment, if it is determined that more likely than not the fair value of the indefinite-lived intangible asset is less than its carrying amount, the Company performs a quantitative impairment test. No impairment charges have resulted from the annual impairment tests.
Income Taxes	'
	Income Taxes — The Company files a consolidated U.S. income tax return with its subsidiaries on a calendar year basis, combined returns for state tax purposes where required and certain of its subsidiaries file separate state income tax returns where required. Deferred tax assets and liabilities are determined based on the differences between the financial statement carrying amounts and tax bases of assets and liabilities using enacted tax rates expected to apply to taxable income in the periods in which the deferred tax asset or liability is expected to be settled or realized. Uncertain tax positions are recognized if they are more likely than not to be sustained upon examination, based on the technical merits of the position. The amount of tax benefit recognized is the largest amount of benefit that is greater than 50% likely of being realized upon settlement. The Company recognizes interest and penalties, if any, related to income tax matters as part of the provision for income taxes on the Consolidated Statements of Income.
Capital Stock	'
	Capital Stock — The authorized capital stock of the Company consists of a single class of common stock and one or more series of preferred stock as may be authorized for issuance by the Company’s board of directors. Voting, dividend, conversion and liquidation rights of the preferred stock would be established by the board of directors upon issuance of such preferred stock.
Stock-Based Compensation	'
	Stock-Based Compensation — The Company measures and recognizes compensation expense based on estimated grant date fair values for all stock-based payment arrangements. Stock-based compensation expense is based on awards expected to vest and therefore is reduced for estimated forfeitures. Forfeitures are estimated at the time of grant based on the Company’s historical forfeiture experience and revised in subsequent periods if actual forfeitures differ from those estimates.
Comprehensive Income (Loss)	'
	Comprehensive Income (Loss) — Comprehensive income (loss) primarily consists of net income and unrealized gains (losses) on securities available-for-sale, net of reclassification adjustments and related income taxes.
Revenue Recognition	'
	Transaction-based Revenues — Client securities trades are recorded on a settlement-date basis with such trades generally settling within three business days after the trade date. Revenues and expenses related to client trades, including revenues from execution agents (also referred to as payment for order flow) and revenues from markups on riskless principal trades in fixed-income securities, are recorded on a trade-date basis. Revenues related to client trades are recorded net of promotional allowances. Securities owned by clients, including those that collateralize margin or similar transactions, are not reflected in the accompanying consolidated financial statements.
	Net Interest Revenue — Net interest revenue primarily consists of income generated by client cash and interest charged to clients on margin balances, net of interest paid to clients on their credit balances. It also includes net interest revenue from securities borrowed and securities loaned transactions. Net interest revenue is recorded when earned.
	Insured Deposit Account Fees — Insured deposit account fees are recognized in the period earned and consist of revenues resulting from the Insured Deposit Account (“IDA”) agreement with TD Bank USA, N.A. (“TD Bank USA”), TD Bank, N.A. and The Toronto-Dominion Bank (“TD”). Under the IDA agreement, TD Bank USA and TD Bank, N.A. (together, the “Depository Institutions”) make available to clients of the Company FDIC-insured money market deposit accounts as either designated sweep vehicles or as non-sweep deposit accounts. The Company provides marketing, recordkeeping and support services for the Depository Institutions with respect to the money market deposit accounts. In exchange for providing these services, the Depository Institutions pay the Company an aggregate marketing fee based on the weighted average yield earned on the client IDA assets, less the actual interest paid to clients, a servicing fee to the Depository Institutions and the cost of FDIC insurance premiums. The IDA agreement is described further in Note 19.
	Investment Product Fees — Investment product fee revenue is recognized in the period earned and consists of revenues earned on client assets invested in money market mutual funds, other mutual funds and certain Company-sponsored investment programs.
	Education Revenue Recognition — The Company recognizes education revenue in accordance with Accounting Standards Codification (“ASC”) 605, Revenue Recognition. Revenue is not recognized until it is realized or realizable and earned. The criteria to meet this guideline are: (a) persuasive evidence of an arrangement exists; (b) delivery has occurred or services have been rendered; (c) the price to the buyer is fixed or determinable; and (d) collectability is reasonably assured. Education revenue is included in other revenues on the Consolidated Statements of Income.
	The Company sells investor education products separately and in various bundles that contain multiple deliverables including on-demand coaching services, website subscriptions, educational workshops, online courses and other products and services. In accordance with ASC 605-25, Multiple-Element Arrangements, sales arrangements with multiple deliverables are divided into separate units of accounting if the deliverables in the arrangement meet the following criteria: (a) the product has value to the client on a standalone basis and (b) delivery or performance of any undelivered item is probable and substantially in the Company’s control. Each of the significant deliverables in our various investor education bundles qualifies as a separate unit of accounting. The relative selling price method is utilized to allocate the arrangement consideration to each deliverable at the inception of the arrangement. The selling price of each deliverable is generally determined by vendor-specific objective evidence, consisting of actual prices charged by the Company when sold separately. In certain arrangements, the Company offers these products bundled together at a discount. The discount is allocated pro rata to each deliverable based on the relative selling price of each deliverable. Deferred revenue arises because the payments are received before the services have been rendered. Deferred revenue is generally recognized into revenue for each deliverable: (a) upon attendance at educational events; (b) upon usage of on-demand services; or (c) over contractual service periods which are usually less than two years.
	The Company provides some limited rights of return in connection with investor education products and services. The Company estimates its returns based on historical experience and maintains an allowance for estimated returns, which is included in deferred revenue on the Consolidated Balance Sheets.
Advertising	'
	Advertising — The Company expenses advertising costs the first time the advertising takes place.
Derivatives and Hedging Activities	'
	Derivatives and Hedging Activities — The Company occasionally utilizes derivative instruments to manage risks, which may include market price, interest rate and foreign currency risks. The Company does not use derivative instruments for speculative or trading purposes. Derivatives are recorded on the Consolidated Balance Sheets as assets or liabilities at fair value. Derivative instruments properly designated to hedge exposure to changes in the fair value of assets or liabilities are accounted for as fair value hedges. Derivative instruments properly designated to hedge exposure to the variability of expected future cash flows or other forecasted transactions are accounted for as cash flow hedges. The Company formally documents the risk management objective and strategy for each hedge transaction. Derivative instruments that do not qualify for hedge accounting are carried at fair value on the Consolidated Balance Sheets with unrealized gains and losses recorded currently on the Consolidated Statements of Income. Cash flows from derivative instruments accounted for as fair value hedges or cash flow hedges are classified in the same category on the Consolidated Statements of Cash Flows as the cash flows from the items being hedged.
Earnings Per Share	'
	Earnings Per Share — Basic earnings per share (“EPS”) is computed by dividing net income by the weighted average common shares outstanding for the period. Diluted EPS reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock, except when such assumed exercise or conversion would have an antidilutive effect on EPS.
Recently Adopted Accounting Pronouncements	'
	Recently Adopted Accounting Pronouncements
	ASU 2011-05 — On October 1, 2012, the Company adopted Accounting Standards Update (“ASU”) 2011-05, Presentation of Comprehensive Income. ASU 2011-05 eliminates the option to present components of other comprehensive income as part of the statement of changes in stockholders’ equity and allows two options for presenting the components of net income and other comprehensive income: (1) in a single continuous statement of comprehensive income or (2) in two separate but consecutive statements, consisting of a statement of net income followed by a separate statement of other comprehensive income. The Company selected the second option for adoption of ASU 2011-05. Adoption of ASU 2011-05 resulted only in changes to the manner in which the components of other comprehensive income are presented in the Company’s financial statements.
	ASU 2011-08 — On October 1, 2012, the Company adopted ASU 2011-08, Testing Goodwill for Impairment. The amendments under ASU 2011-08 allow entities to first assess qualitative factors to determine whether it is necessary to perform the two-step quantitative goodwill impairment test. Under these amendments, an entity is not required to calculate the fair value of a reporting unit unless the entity determines, based on a qualitative assessment, that it is more likely than not that its fair value is less than its carrying amount. The amendments include a number of events and circumstances for entities to consider in conducting the qualitative assessment. Entities have the option to bypass the qualitative assessment for any reporting unit in any period and proceed directly to performing the first step of the two-step quantitative goodwill impairment test. Adoption of ASU 2011-08 did not have an impact on the Company’s financial statements.
	ASU 2012-02 — On October 1, 2012 the Company adopted ASU 2012-02, Testing Indefinite-Lived Intangible Assets for Impairment. The amendments in ASU 2012-02 allow entities to first to assess qualitative factors to determine whether the existence of events and circumstances indicates that it is more likely than not that an indefinite-lived intangible asset is impaired. If, after assessing the totality of events and circumstances, an entity concludes that it is not more likely than not that the indefinite-lived intangible asset is impaired, then the entity is not required to take further action. However, if an entity concludes otherwise, then it is required to determine the fair value of the indefinite-lived intangible asset and perform the quantitative impairment test by comparing the fair value with the carrying amount. Entities have the option to bypass the qualitative assessment for any indefinite-lived intangible asset in any period and proceed directly to performing the quantitative impairment test. Adoption of ASU 2012-02 did not have an impact on the Company’s financial statements.
Recently Issued Accounting Pronouncements	'
	Recently Issued Accounting Pronouncements
	ASU 2011-11 — In December 2011, the Financial Accounting Standards Board (“FASB”) issued ASU 2011-11, Disclosures about Offsetting Assets and Liabilities, and further clarified the scope of these disclosures by issuing ASU 2013-01, Clarifying the Scope of Disclosures about Offsetting Assets and Liabilities, in January 2013. The amendments in these ASUs will enhance disclosures by requiring improved information about financial and derivative instruments, including bifurcated embedded derivatives, repurchase agreements and reverse repurchase agreements, and securities borrowing and securities lending transactions that are either (1) offset (netting assets and liabilities) in accordance with Section 210-20-45 or Section 815-10-45 of the FASB Accounting Standards Codification or (2) subject to an enforceable master netting arrangement or similar agreement. ASU 2011-11 and ASU 2013-01 are effective for annual periods beginning on or after January 1, 2013, and interim periods within those annual periods, and require retrospective disclosures for comparative periods presented. Therefore, these ASUs will be effective for the Company’s fiscal year beginning October 1, 2013. Adoption of ASU 2011-11 and ASU 2013-01 is not expected to have a material impact on the Company’s financial statements.
Loss Contingencies (ASC) 450	'
	These matters could result in censures, fines, penalties or other sanctions. ASC 450, Loss Contingencies, governs the recognition and disclosure of loss contingencies, including potential losses from legal and regulatory matters. ASC 450 categorizes loss contingencies using three terms based on the likelihood of occurrence of events that result in a loss: “probable” means that “the future event or events are likely to occur;” “remote” means that “the chance of the future event or events occurring is slight;” “and “reasonably possible” means that “the chance of the future event or events occurring is more than remote but less than likely.” Under ASC 450, the Company accrues for losses that are considered both probable and reasonably estimable.
Fair Value Measurement (ASC) 820-10	'
	ASC 820-10, Fair Value Measurement, defines fair value as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the measurement date.
	ASC 820-10 establishes a hierarchy for inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the most observable inputs be used when available. Observable inputs reflect the assumptions market participants would use in pricing the asset or liability, developed based on market data obtained from sources independent of the Company. Unobservable inputs reflect the Company’s own assumptions about the assumptions market participants would use in pricing the asset or liability, developed based on the best information available in the circumstances.

Goodwill_and_Acquired_Intangib1

Goodwill and Acquired Intangible Assets (Tables)	12 Months Ended
	Sep. 30, 2013
Goodwill And Intangible Assets Disclosure [Abstract]	'
Acquired Intangible Assets	'
	Acquired intangible assets consist of the following (dollars in millions):
		September 30,
		2013							2012
		Gross		Accumulated			Net		Gross		Accumulated			Net
		Carrying		Amortization			Carrying		Carrying		Amortization			Carrying
		Amount					Amount		Amount					Amount
	Client relationships	$	1,228	$	(569	)	$	659	$	1,228	$	(493	)	$	735
	Technology and content		99		(63	)		36		99		(48	)		51
	Trademark license		146		—			146		146		—			146
		$	1,473	$	(632	)	$	841	$	1,473	$	(541	)	$	932
Estimated Future Amortization Expense for Acquired Intangible Assets	'
	Amortization expense on acquired intangible assets was $91 million, $92 million and $97 million for fiscal years 2013, 2012 and 2011, respectively. Estimated future amortization expense for acquired intangible assets outstanding as of September 30, 2013 is as follows (dollars in millions):
	Fiscal Year	Estimated
		Amortization
		Expense
	2014	$	90
	2015		90
	2016		85
	2017		76
	2018		72
	Thereafter (to 2025)		282
	Total	$	695

Cash_and_Cash_Equivalents_Tabl

Cash and Cash Equivalents (Tables)	12 Months Ended
	Sep. 30, 2013
Cash And Cash Equivalents [Abstract]	'
Summary of Cash and Cash Equivalents	'
	The Company’s cash and cash equivalents is summarized in the following table (dollars in millions):
		September 30,
		2013		2012
	Corporate	$	429	$	403
	Broker-dealer subsidiaries		540		406
	Trust company subsidiary		74		95
	Investment advisory subsidiaries		19		11
	Total	$	1,062	$	915

Cash_and_Investments_Segregate1

Cash and Investments Segregated and on Deposit for Regulatory Purposes (Tables)	12 Months Ended
	Sep. 30, 2013
Receivables [Abstract]	'
Cash and Investments Segregated and on Deposit for Regulatory Purposes	'
	Cash and investments segregated and on deposit for regulatory purposes consists of the following (dollars in millions):
		September 30,
		2013		2012
	Reverse repurchase agreements (collateralized by U.S. government debt securities)	$	2,618	$	2,181
	U.S. government debt securities		1,995		1,564
	Cash in demand deposit accounts		1,154		179
	Cash on deposit with futures commission merchant		77		96
	U.S. government debt securities on deposit with futures commission merchant		50		10
	Total	$	5,894	$	4,030

Receivable_from_and_Payable_to1

Receivable from and Payable to Brokers, Dealers and Clearing Organizations (Tables)	12 Months Ended
	Sep. 30, 2013
Brokers And Dealers [Abstract]	'
Amounts Receivable from and Payable to Brokers, Dealers and Clearing Organizations	'
	Amounts receivable from and payable to brokers, dealers and clearing organizations consist of the following (dollars in millions):
		September 30,
		2013		2012
	Receivable:
	Deposits paid for securities borrowed	$	1,220	$	924
	Broker-dealers		9		2
	Deposits with clearing organizations		115		177
	Securities failed to deliver		4		7
	Total	$	1,348	$	1,110
	Payable:
	Deposits received for securities loaned	$	1,948	$	1,940
	Broker-dealers		2		3
	Clearing organizations		15		—
	Securities failed to receive		8		49
	Total	$	1,973	$	1,992

Allowance_for_Doubtful_Account1

Allowance for Doubtful Accounts on Receivables (Tables)	12 Months Ended
	Sep. 30, 2013
Valuation And Qualifying Accounts [Abstract]	'
Allowance for Doubtful Accounts on Client and Other Receivables	'
	The following table summarizes activity in the Company’s allowance for doubtful accounts on client and other receivables for the fiscal years indicated (dollars in millions):
		2013			2012			2011
	Beginning balance	$	21		$	18		$	11
	Provision for (recovery of) doubtful accounts, net		(1	)		9			9
	Write-off of doubtful accounts		(5	)		(6	)		(2	)
	Ending balance	$	15		$	21		$	18

Property_and_Equipment_Tables

Property and Equipment (Tables)	12 Months Ended
	Sep. 30, 2013
Property Plant And Equipment [Abstract]	'
Schedule of Property and Equipment	'
	Property and equipment consists of the following (dollars in millions):
		September 30,
		2013			2012
	Computer equipment	$	205		$	190
	Building and building components		198			—
	Building construction in process		—			164
	Leasehold improvements		148			147
	Software		144			117
	Land		17			13
	Other property and equipment		67			48
			779			679
	Less: Accumulated depreciation and amortization		(282	)		(235	)
	Property and equipment, net	$	497		$	444

Longterm_Debt_and_Credit_Facil1

Long-term Debt and Credit Facilities (Tables)	12 Months Ended
	Sep. 30, 2013
Debt Disclosure [Abstract]	'
Schedule of Long Term Debt	'
	Long-term debt consists of the following (dollars in millions):
	September 30, 2013		Face			Unamortized			Fair Value			Net Carrying
			Value			Discount			Adjustment(1)			Value
	Senior Notes:
	4.150% Senior Notes due 2014		$	500		$	—		$	15		$	515
	5.600% Senior Notes due 2019			500			—			37			537
	Total long-term debt		$	1,000		$	—		$	52		$	1,052
	September 30, 2012		Face			Unamortized			Fair Value			Net Carrying
			Value			Discount			Adjustment(1)			Value
	Senior Notes:
	2.950% Senior Notes due 2012		$	250		$	—		$	1		$	251
	4.150% Senior Notes due 2014			500			—			27			527
	5.600% Senior Notes due 2019			500			(1	)		68			567
	Total long-term debt		$	1,250		$	(1	)	$	96		$	1,345
	-1	Fair value adjustments relate to changes in the fair value of the debt while in a fair value hedging relationship. See “Interest Rate Swaps” below.
Fiscal Year Maturities on Long-term Debt Outstanding	'
	Fiscal year maturities on long-term debt outstanding at September 30, 2013 are as follows (dollars in millions):
	2014		$	—
	2015			500
	2016			—
	2017			—
	2018			—
	Thereafter			500
	Total		$	1,000
Gains and Losses Resulting from Changes in Fair Value of Interest Rate Swaps and Hedged Fixed-rate Debt	'
	The following table summarizes gains and losses resulting from changes in the fair value of the interest rate swaps and the hedged fixed-rate debt for the fiscal years indicated (dollars in millions):
			2013			2012			2011
	Gain (loss) on fair value of interest rate swaps		$	(44	)	$	8		$	39
	Gain (loss) on fair value of hedged fixed-rate debt			44			(8	)		(39	)
	Net gain (loss) recorded in interest on borrowings		$	—		$	—		$	—
Fair Value of Outstanding Derivatives Designated as Hedging Instruments	'
	The following table summarizes the fair value of outstanding derivatives designated as hedging instruments on the Consolidated Balance Sheets (dollars in millions):
			September 30,
			2013			2012
	Derivatives recorded under the caption Other assets:
	Interest rate swap assets		$	52		$	96

Income_Taxes_Tables

Income Taxes (Tables)	12 Months Ended
	Sep. 30, 2013
Income Tax Disclosure [Abstract]	'
Provision for Income Taxes	'
	Provision for income taxes is comprised of the following for the fiscal years indicated (dollars in millions):
		2013			2012			2011
	Current expense:
	Federal	$	370		$	314		$	357
	State		33			1			20
			403			315			377
	Deferred expense (benefit):
	Federal		(2	)		(2	)		(5	)
	State		12			7			7
			10			5			2
	Provision for income taxes	$	413		$	320		$	379
Reconciliation of Federal Statutory Tax Rate to Effective Tax Rate	'
	A reconciliation of the federal statutory tax rate to the effective tax rate applicable to pre-tax income follows for the fiscal years indicated:
		2013			2012			2011
	Federal statutory rate		35	%		35	%		35	%
	State taxes, net of federal tax effect		2.6			2.1			2.3
	Adjustments to estimated state income taxes		0.4			0.1			(0.1	)
	Interest recorded on unrecognized tax benefits, net		0.3			0.1			0.5
	Reversal of accruals for unrecognized tax benefits		(0.3	)		(1.7	)		(0.5	)
	Reversal of capital loss valuation allowance		—			(0.4	)		—
	Other		—			0.1			0.1
			38	%		35.3	%		37.3	%
Deferred Tax Assets (Liabilities)	'
	Deferred tax assets (liabilities) are comprised of the following (dollars in millions):
		September 30,
		2013			2012
	Deferred tax assets:
	Accrued liabilities	$	72		$	69
	Intangible assets, state tax benefit		12			15
	Stock-based compensation		36			30
	Allowance for doubtful accounts		6			8
	Unrealized tax gain on IDA agreement		—			9
	Operating loss carryforwards		21			40
	Other deferred tax assets		3			6
	Gross deferred tax assets		150			177
	Less: Valuation allowance		(18	)		(37	)
	Net deferred tax assets		132			140
	Deferred tax liabilities:
	Property and intangible assets		(478	)		(478	)
	Unrealized investment gains		—			(10	)
	Other deferred tax liabilities		(5	)		(4	)
	Total deferred tax liabilities		(483	)		(492	)
	Net deferred tax liabilities	$	(351	)	$	(352	)
Reconciliation of Activity Related to Unrecognized Tax Benefits	'
	A reconciliation of the activity related to unrecognized tax benefits follows for the fiscal years indicated (dollars in millions):
		2013			2012			2011
	Beginning balance	$	139		$	145		$	149
	Additions based on tax positions related to the current year		8			10			10
	Additions for tax positions of prior years		2			8			7
	Reductions for tax positions of prior years		(5	)		(3	)		(12	)
	Reductions due to settlements with taxing authorities		(1	)		(5	)		(1	)
	Reductions due to lapsed statute of limitations		(6	)		(16	)		(8	)
	Ending balance	$	137		$	139		$	145

Capital_Requirements_Tables

Capital Requirements (Tables)	12 Months Ended
	Sep. 30, 2013
Text Block [Abstract]	'
Net Capital and Net Capital Requirements for Company's Broker-dealer Subsidiaries	'
	Net capital and net capital requirements for the Company’s broker-dealer subsidiaries are summarized in the following tables (dollars in millions):
	TD Ameritrade Clearing, Inc.
	Date	Net Capital		Required		Net Capital		Net Capital		Ratio of
				Net Capital		in Excess of		in Excess of		Net Capital
				(2% of		Required		Early Warning		to Aggregate
				Aggregate		Net Capital		Threshold		Debit Balances
				Debit Balances)				(5% of
								Aggregate
								Debit Balances)
	30-Sep-13	$	1,302	$	222	$	1,080	$	746		11.7	%
	30-Sep-12	$	1,302	$	203	$	1,099	$	796		12.86	%
	TD Ameritrade, Inc.
	Date	Net Capital		Required		Net Capital		Net Capital
				Net Capital		in Excess of		in Excess of
				(8% of Total		Required		Early Warning
				Risk Margin)		Net Capital		Threshold
								(110% of
								Required
								Net Capital)
	30-Sep-13	$	305	$	10	$	295	$	294
	30-Sep-12	$	261	$	8	$	253	$	252

Stockbased_Compensation_Tables

Stock-based Compensation (Tables)	12 Months Ended
	Sep. 30, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Summary of Option Activity in Stock Incentive Plans	'
	The following is a summary of option activity in the Company’s stock incentive plans for the fiscal year ended September 30, 2013:
		Number of			Weighted		Weighted		Aggregate
		Options			Average		Average		Intrinsic
		(in thousands)			Exercise		Remaining		Value
					Price		Contractual		(in millions)
							Term (Years)
	Outstanding at beginning of year		7,190		$	9.31
	Exercised		(4,600	)	$	4.13
	Expired		(47	)	$	26.52
	Outstanding at end of year		2,543		$	18.36		5.1	$	20
	Exercisable at end of year		2,515		$	18.34		5.1	$	20
Summary of Restricted Stock Units Activity in Stock Incentive Plans	'
	The following is a summary of RSU activity in the Company’s stock incentive plans for the fiscal year ended September 30, 2013:
		Number of			Weighted
		Units			Average
		(in thousands)			Grant Date
					Fair Value
	Nonvested at beginning of year		4,139		$	17.74
	Granted		2,172		$	16.38
	Dividend equivalents		235		$	16.92
	Vested		(861	)	$	19.13
	Forfeited		(334	)	$	17.15
	Nonvested at end of year		5,351		$	17

Earnings_Per_Share_Tables

Earnings Per Share (Tables)	12 Months Ended
	Sep. 30, 2013
Earnings Per Share [Abstract]	'
Computation of Basic and Diluted Earnings Per Share	'
	The following is a reconciliation of the numerator and denominator used in the computation of basic and diluted earnings per share for the fiscal years indicated (in millions, except per share amounts):
			2013		2012		2011
	Net income		$	675	$	586	$	638
	Weighted average shares outstanding - basic			549		548		570
	Effect of dilutive securities:
	Common stock equivalent shares related to stock-based compensation			5		6		6
	Weighted average shares outstanding - diluted (1)			554		554		576
	Earnings per share - basic		$	1.23	$	1.07	$	1.12
	Earnings per share - diluted		$	1.22	$	1.06	$	1.11
	-1	The Company excluded from the calculation of diluted earnings per share 0.7 million, 2.5 million and 1.5 million shares underlying stock-based compensation awards for the fiscal years ended September 30, 2013, 2012 and 2011, respectively, because their inclusion would have been antidilutive.

Commitments_and_Contingencies_

Commitments and Contingencies (Tables)	12 Months Ended
	Sep. 30, 2013
Commitments And Contingencies Disclosure [Abstract]	'
Future Minimum Rental Commitments Under Non-Cancelable Operating Leases	'
	Lease Commitments — The Company has various non-cancelable operating leases on facilities and certain office equipment requiring annual payments as follows (dollars in millions):
	Fiscal Year	Minimum		Sublease			Net Lease
		Lease		Income			Commitments
		Payments
	2014	$	52	$	(1	)	$	51
	2015		48		(1	)		47
	2016		45		(1	)		44
	2017		45		(2	)		43
	2018		42		(1	)		41
	Thereafter (to 2029)		109		(1	)		108
	Total	$	341	$	(7	)	$	334
Collateral Available, Loaned or Repledged	'
	The following table summarizes the fair values of client margin securities and stock borrowings that were available to the Company to utilize as collateral on various borrowings or for other purposes, and the amount of that collateral loaned or repledged by the Company (dollars in billions):
		September 30,
		2013		2012
	Client margin securities	$	12.5	$	12
	Stock borrowings		1.2		0.9
	Total collateral available	$	13.7	$	12.9
	Collateral loaned	$	1.9	$	1.9
	Collateral repledged		1.8		1.2
	Total collateral loaned or repledged	$	3.7	$	3.1
Summary of Cash Deposited with and Securities Pledged to Clearinghouses	'
	The Company is subject to cash deposit and collateral requirements with clearinghouses based on its clients’ trading activity. The following table summarizes cash deposited with and securities pledged to clearinghouses by the Company (dollars in millions):
		September 30,
		2013		2012
	Cash	$	115	$	121
	U.S. government debt securities		61		56
	Total	$	176	$	177

Fair_Value_Disclosures_Tables

Fair Value Disclosures (Tables)	12 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Fair Value Hierarchy for Assets and Liabilities Measured on Recurring Basis	'
	The following tables present the Company’s fair value hierarchy for assets and liabilities measured at fair value on a recurring basis as of September 30, 2013 and 2012 (dollars in millions):
			As of September 30, 2013
			Level 1			Level 2			Level 3			Fair Value
	Assets:
	Cash equivalents:
	Money market mutual funds		$	969		$	—		$	—		$	969
	Short-term investments available-for-sale:
	U.S. government debt securities			—			4			—			4
	Investments segregated for regulatory purposes:
	U.S. government debt securities			—			2,045			—			2,045
	Securities owned:
	Auction rate securities			—			—			5			5
	Money market and other mutual funds			—			—			1			1
	U.S. government debt securities			—			313			—			313
	Other			1			3			—			4
	Subtotal — Securities owned			1			316			6			323
	Investments available-for-sale:
	Equity securities			13			—			—			13
	Other assets:
	Interest rate swaps(1)			—			52			—			52
	Total assets at fair value		$	983		$	2,417		$	6		$	3,406
	Liabilities:
	Accounts payable and accrued liabilities:
	Securities sold, not yet purchased:
	Equity securities		$	13		$	—		$	—		$	13
	-1	See “Interest Rate Swaps” in Note 9 for details.
			As of September 30, 2012
			Level 1			Level 2			Level 3			Fair Value
	Assets:
	Cash equivalents:
	Money market mutual funds		$	768		$	—		$	—		$	768
	U.S. government debt securities			—			50			—			50
	Subtotal — Cash equivalents			768			50			—			818
	Short-term investments available-for-sale:
	U.S. government debt securities			—			154			—			154
	Investments segregated for regulatory purposes:
	U.S. government debt securities			—			1,574			—			1,574
	Securities owned:
	Auction rate securities			—			—			6			6
	Money market and other mutual funds			—			—			1			1
	U.S. government debt securities			—			333			—			333
	Other			1			2			—			3
	Subtotal—Securities owned			1			335			7			343
	Investments available-for-sale:
	Convertible preferred equity securities			—			70			—			70
	Other assets:
	Interest rate swaps(1)			—			96			—			96
	Total assets at fair value		$	769		$	2,279		$	7		$	3,055
	Liabilities:
	Accounts payable and accrued liabilities:
	Securities sold, not yet purchased:
	Equity securities		$	3		$	—		$	—		$	3
	-1	See “Interest Rate Swaps” in Note 9 for details.
Changes in Level 3 Assets Measured on Recurring Basis	'
	The following tables present the changes in Level 3 assets measured at fair value on a recurring basis for the fiscal years ended September 30, 2013, 2012 and 2011 (dollars in millions):
			Year Ended September 30,
			2013						2012
			Auction Rate			Money Market			Auction Rate			Money Market
			Securities			and Other			Securities			and Other
						Mutual Funds						Mutual Funds
	Balance, beginning of year		$	6		$	1		$	20		$	1
	Purchases			—			—			1			—
	Sales			—			—			(2	)		—
	Settlements			(1	)		—			(13	)		—
	Balance, end of year		$	5		$	1		$	6		$	1
			Year Ended September 30, 2011
			Auction Rate			Money Market
			Securities			and Other
						Mutual Funds
	Balance, beginning of year		$	209		$	5
	Net gains included in earnings			5	(1)		—
	Purchases, sales, issuances and settlements, net			(194	)		(4	)
	Balance, end of year		$	20		$	1
	-1	Net gains on auction rate securities are recorded in other revenues on the Consolidated Statements of Income. For the year ended September 30, 2011, substantially all of the net gains on auction rate securities related to assets not held as of September 30, 2011.
Quantitative Information about Level 3 Unobservable Inputs	'
	The following tables summarize quantitative information about Level 3 unobservable inputs as of September 30, 2013 and 2012:
	As of September 30, 2013
	Asset		Valuation		Unobservable	Range		Weighted
			Technique		Input			Average
	Auction Rate Securities		Discounted		Constant	10% - 20%		15%
			cash flow		prepayment rate
					(Annual)
					Yield premium for	2%		2%
					illiquidity
	As of September 30, 2012
	Asset		Valuation		Unobservable	Range		Weighted
			Technique		Input			Average
	Auction Rate Securities		Discounted		Constant	15% - 20%		17%
			cash flow		prepayment rate
					(Annual)
					Yield premium for	2%		2%
					illiquidity

Related_Party_Transactions_Tab

Related Party Transactions (Tables)	12 Months Ended
	Sep. 30, 2013
Related Party Transactions [Abstract]	'
Summary of Revenues Resulting from Transactions with Related Parties	'
	The following tables summarize revenues and expenses resulting from transactions with TD and its affiliates for the fiscal years indicated (dollars in millions):
	Description	Statement of Income		Revenues from TD and Affiliates
		Classification		2013				2012		2011
	Insured Deposit Account Agreement	Insured deposit account fees		$	804			$	828	$	763
	Mutual Fund Agreements	Investment product fees			1				3		8
	Referral and Strategic Alliance Agreement	Various			11				8		4
	Securities borrowing and lending, net	Net interest revenue			2				3		4
	Other	Various			3				2		3
	Total revenues			$	821			$	844	$	782
Summary of Expenses Resulting from Transactions with Related Parties	'
	Description	Statement of Income		Expenses to TD and Affiliates
		Classification		2013				2012		2011
	Canadian Call Center Services Agreement	Professional Services		$	19			$	18	$	18
	Other	Various			4				4		4
	Total expenses			$	23			$	22	$	22
Summary of Classification and Amount of Receivables from and Payables to Affiliates of Company	'
	The following table summarizes the classification and amount of receivables from and payables to TD and its affiliates on the Consolidated Balance Sheets resulting from related party transactions (dollars in millions):
		September 30,
		2013				2012
	Assets:
	Receivable from brokers, dealers and clearing organizations	$	1			$	1
	Receivable from affiliates		117				85
	Liabilities:
	Payable to brokers, dealers and clearing organizations	$	115			$	125
	Payable to affiliates		4				4

Condensed_Consolidating_Financ1

Condensed Consolidating Financial Information (Tables)	12 Months Ended
	Sep. 30, 2013
Organization Consolidation And Presentation Of Financial Statements [Abstract]	'
Schedule of Condensed Consolidating Balance Sheet	'
	CONDENSED CONSOLIDATING BALANCE SHEET
	As of September 30, 2013
		Parent			Guarantor			Non-Guarantor			Eliminations			Total
					Subsidiary			Subsidiaries
		(In millions)
	ASSETS
	Cash and cash equivalents	$	199		$	7		$	856		$	—		$	1,062
	Short-term investments available-for-sale		—			—			4			—			4
	Cash and investments segregated and on deposit for regulatory purposes		—			—			5,894			—			5,894
	Receivable from brokers, dealers and clearing organizations		—			—			1,348			—			1,348
	Receivable from clients, net		—			—			8,984			—			8,984
	Investments in subsidiaries		5,568			5,360			550			(11,478	)		—
	Receivable from affiliates		4			3			117			(7	)		117
	Goodwill		—			—			2,467			—			2,467
	Acquired intangible assets, net		—			146			695			—			841
	Other, net		140			9			1,011			(41	)		1,119
	Total assets	$	5,911		$	5,525		$	21,926		$	(11,526	)	$	21,836
	LIABILITIES AND STOCKHOLDERS’ EQUITY
	Liabilities:
	Payable to brokers, dealers and clearing organizations	$	—		$	—		$	1,973		$	—		$	1,973
	Payable to clients		—			—			13,183			—			13,183
	Accounts payable and accrued liabilities		180			—			410			(8	)		582
	Payable to affiliates		3			—			8			(7	)		4
	Long-term debt		1,052			—			—			—			1,052
	Other		—			51			348			(33	)		366
	Total liabilities		1,235			51			15,922			(48	)		17,160
	Stockholders’ equity		4,676			5,474			6,004			(11,478	)		4,676
	Total liabilities and stockholders’ equity	$	5,911		$	5,525		$	21,926		$	(11,526	)	$	21,836
	CONDENSED CONSOLIDATING BALANCE SHEET
	As of September 30, 2012
		Parent			Guarantor			Non-Guarantor			Eliminations			Total
					Subsidiary			Subsidiaries
		(In millions)
	ASSETS
	Cash and cash equivalents	$	178		$	6		$	731		$	—		$	915
	Short-term investments available-for-sale		151			—			3			—			154
	Cash and investments segregated and on deposit for regulatory purposes		—			—			4,030			—			4,030
	Receivable from brokers, dealers and clearing organizations		—			—			1,110			—			1,110
	Receivable from clients, net		—			—			8,647			—			8,647
	Investments in subsidiaries		5,456			5,250			548			(11,254	)		—
	Receivable from affiliates		5			3			83			(6	)		85
	Goodwill		—			—			2,467			—			2,467
	Acquired intangible assets, net		—			146			786			—			932
	Other, net		230			7			961			(25	)		1,173
	Total assets	$	6,020		$	5,412		$	19,366		$	(11,285	)	$	19,513
	LIABILITIES AND STOCKHOLDERS’ EQUITY
	Liabilities:
	Payable to brokers, dealers and clearing organizations	$	—		$	—		$	1,992		$	—		$	1,992
	Payable to clients		—			—			10,728			—			10,728
	Accounts payable and accrued liabilities		249			—			391			(8	)		632
	Payable to affiliates		1			—			9			(6	)		4
	Long-term debt		1,345			—			—			—			1,345
	Other		—			48			356			(17	)		387
	Total liabilities		1,595			48			13,476			(31	)		15,088
	Stockholders’ equity		4,425			5,364			5,890			(11,254	)		4,425
	Total liabilities and stockholders’ equity	$	6,020		$	5,412		$	19,366		$	(11,285	)	$	19,513
Schedule of Condensed Consolidating Statement of Income	'
	CONDENSED CONSOLIDATING STATEMENT OF INCOME
	For the Year Ended September 30, 2013
		Parent			Guarantor			Non-Guarantor			Eliminations			Total
					Subsidiary			Subsidiaries
		(In millions)
	Net revenues	$	12		$	—		$	2,763		$	(11	)	$	2,764
	Operating expenses		10			—			1,709			(11	)		1,708
	Operating income		2			—			1,054			—			1,056
	Other income		(23	)		—			(9	)		—			(32	)
	Income before income taxes and equity in income of subsidiaries		25			—			1,063			—			1,088
	Provision for income taxes		8			—			405			—			413
	Income before equity in income of subsidiaries		17			—			658			—			675
	Equity in income of subsidiaries		658			634			36			(1,328	)		—
	Net income	$	675		$	634		$	694		$	(1,328	)	$	675
	CONDENSED CONSOLIDATING STATEMENT OF INCOME
	For the Year Ended September 30, 2012
		Parent			Guarantor			Non-Guarantor			Eliminations			Total
					Subsidiary			Subsidiaries
		(In millions)
	Net revenues	$	32		$	—		$	2,641		$	(32	)	$	2,641
	Operating expenses		28			—			1,711			(32	)		1,707
	Operating income		4			—			930			—			934
	Other expense (income)		29			—			(1	)		—			28
	Income (loss) before income taxes and equity in income of subsidiaries		(25	)		—			931			—			906
	Provision for (benefit from) income taxes		(19	)		(3	)		342			—			320
	Income (loss) before equity in income of subsidiaries		(6	)		3			589			—			586
	Equity in income of subsidiaries		592			577			33			(1,202	)		—
	Net income	$	586		$	580		$	622		$	(1,202	)	$	586
	CONDENSED CONSOLIDATING STATEMENT OF INCOME
	For the Year Ended September 30, 2011
		Parent			Guarantor			Non-Guarantor			Eliminations			Total
					Subsidiary			Subsidiaries
		(In millions)
	Net revenues	$	17		$	—		$	2,763		$	(17	)	$	2,763
	Operating expenses		16			—			1,716			(17	)		1,715
	Operating income		1			—			1,047			—			1,048
	Other expense (income)		33			—			(2	)		—			31
	Income (loss) before income taxes and equity in income of subsidiaries		(32	)		—			1,049			—			1,017
	Provision for (benefit from) income taxes		(13	)		(1	)		393			—			379
	Income (loss) before equity in income of subsidiaries		(19	)		1			656			—			638
	Equity in income of subsidiaries		657			673			38			(1,368	)		—
	Net income	$	638		$	674		$	694		$	(1,368	)	$	638
Schedule of Condensed Consolidating Statement of Cash Flows	'
	CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
	For the Year Ended September 30, 2013
		Parent			Guarantor			Non-Guarantor			Total
					Subsidiary			Subsidiaries
		(In millions)
	Net cash provided by (used in) operating activities	$	(70	)	$	1		$	808		$	739
	Cash flows from investing activities:
	Purchase of property and equipment		—			—			(144	)		(144	)
	Proceeds from sale and maturity of short-term investments		150			—			4			154
	Purchase of short-term investments		—			—			(4	)		(4	)
	Proceeds from sale of investments		78			—			10			88
	Other, net		—			—			2			2
	Net cash provided by (used in) investing activities		228			—			(132	)		96
	Cash flows from financing activities:
	Principal payments on long-term debt		(250	)		—			—			(250	)
	Proceeds from notes payable		275			—			—			275
	Principal payments on notes payable		(275	)		—			—			(275	)
	Payment of cash dividends		(471	)		—			—			(471	)
	Purchase of treasury stock		(5	)		—			—			(5	)
	Other, net		43			—			(5	)		38
	Net cash used in financing activities		(683	)		—			(5	)		(688	)
	Intercompany investing and financing activities, net		546			—			(546	)		—
	Net increase in cash and cash equivalents		21			1			125			147
	Cash and cash equivalents at beginning of year		178			6			731			915
	Cash and cash equivalents at end of year	$	199		$	7		$	856		$	1,062
	CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
	For the Year Ended September 30, 2012
		Parent			Guarantor			Non-Guarantor			Total
					Subsidiary			Subsidiaries
		(In millions)
	Net cash provided by operating activities	$	46		$	2		$	544		$	592
	Cash flows from investing activities:
	Purchase of property and equipment		—			—			(186	)		(186	)
	Purchase of short-term investments		(152	)		—			(3	)		(155	)
	Purchase of investments		(43	)		—			(1	)		(44	)
	Proceeds from sale of investments		2			—			—			2
	Proceeds from sale and maturity of short-term investments		—			—			4			4
	Other, net		—			—			2			2
	Net cash used in investing activities		(193	)		—			(184	)		(377	)
	Cash flows from financing activities:
	Purchase of treasury stock		(208	)		—			—			(208	)
	Payment of cash dividends		(132	)		—			—			(132	)
	Other, net		4			—			4			8
	Net cash provided by (used in) financing activities		(336	)		—			4			(332	)
	Intercompany investing and financing activities, net		567			(3	)		(564	)		—
	Net increase (decrease) in cash and cash equivalents		84			(1	)		(200	)		(117	)
	Cash and cash equivalents at beginning of year		94			7			931			1,032
	Cash and cash equivalents at end of year	$	178		$	6		$	731		$	915
	CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
	For the Year Ended September 30, 2011
		Parent			Guarantor			Non-Guarantor			Total
					Subsidiary			Subsidiaries
		(In millions)
	Net cash provided by (used in) operating activities	$	(45	)	$	202		$	633		$	790
	Cash flows from investing activities:
	Purchase of property and equipment		—			—			(153	)		(153	)
	Purchase of short-term investments		—			—			(4	)		(4	)
	Purchase of investments		—			—			(5	)		(5	)
	Proceeds from sale of investments		—			—			3			3
	Proceeds from sale and maturity of short-term investments		—			—			4			4
	Other, net		—			—			3			3
	Net cash used in investing activities		—			—			(152	)		(152	)
	Cash flows from financing activities:
Principal payments on long-term debt		—			—			(4	)		(4	)
Purchase of treasury stock		(349	)		—			—			(349	)
Return of prepayment on structured stock repurchase		119			—			—			119
Payment of cash dividends		(114	)		—			—			(114	)
Other, net		13			—			(12	)		1
Net cash used in financing activities		(331	)		—			(16	)		(347	)
Intercompany investing and financing activities, net		403			(220	)		(183	)		—
Net increase (decrease) in cash and cash equivalents		27			(18	)		282			291
Cash and cash equivalents at beginning of year		67			25			649			741
Cash and cash equivalents at end of year	$	94		$	7		$	931		$	1,032

Quarterly_Data_Unaudited_Table

Quarterly Data (Unaudited) (Tables)	12 Months Ended
	Sep. 30, 2013
Quarterly Financial Information Disclosure [Abstract]	'
Schedule of Quarterly Financial Data	'
			For the Fiscal Year Ended September 30, 2013
			First		Second		Third		Fourth
			Quarter		Quarter		Quarter		Quarter(1)
	Net revenues		$	651	$	679	$	725	$	709
	Operating income		$	241	$	237	$	298	$	279
	Net income		$	147	$	144	$	184	$	200
	Basic earnings per share		$	0.27	$	0.26	$	0.33	$	0.36
	Diluted earnings per share		$	0.27	$	0.26	$	0.33	$	0.36
			For the Fiscal Year Ended September 30, 2012
			First		Second		Third		Fourth
			Quarter		Quarter		Quarter		Quarter
	Net revenues		$	653	$	673	$	667	$	647
	Operating income		$	228	$	219	$	254	$	232
	Net income		$	152	$	137	$	154	$	143
	Basic earnings per share		$	0.28	$	0.25	$	0.28	$	0.26
	Diluted earnings per share		$	0.27	$	0.25	$	0.28	$	0.26
		-1	The Company’s results of operations for the fourth quarter of fiscal 2013 include a pre-tax gain of $54 million ($34 million after tax, or $0.06 per diluted share) in connection with Knight Capital Group, Inc.’s July 1, 2013 merger with GETCO Holding Company, LLC. For more information regarding the Knight-GETCO merger, see Note 7.

Nature_of_Operations_and_Summa2

Nature of Operations and Summary of Significant Accounting Policies - Additional Information (Detail) (USD $)	12 Months Ended
	Sep. 30, 2013
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]	'
Maturity period of cash equivalents (three months or less)	'3 months
General maturity of the Company's reverse repurchase agreements which are collateralized by U.S. Treasury securities	'7 days
The amount of impairment charges that have resulted from the goodwill annual impairment tests	$0
Estimated useful service life of acquired intangible assets, minimum, in years	'3 years
Estimated useful service life of acquired intangible assets, maximum, in years	'23 years
The amount of impairment charges that have resulted from the intangible assets annual impairment tests	$0
Number of business days that client securities transactions generally settle within (in business days)	'3 days
General timing of the recognition of deferred revenue into revenue (in years)	'Less than two years
Minimum [Member]	'
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]	'
Percent likelihood for tax benefit amounts to be realized upon settlement	50.00%
Minimum [Member] | All Other Depreciable Property and Equipment [Member]	'
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]	'
Estimated useful service lives	'3 years
Minimum [Member] | Building and Building Components [Member]	'
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]	'
Estimated useful service lives	'10 years
Maximum [Member] | All Other Depreciable Property and Equipment [Member]	'
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]	'
Estimated useful service lives	'7 years
Maximum [Member] | Building and Building Components [Member]	'
Organization Consolidation And Presentation Of Financial Statements Disclosure [Line Items]	'
Estimated useful service lives	'40 years

Goodwill_and_Acquired_Intangib2

Goodwill and Acquired Intangible Assets - Acquired Intangible Assets (Detail) (USD $)	Sep. 30, 2013	Sep. 30, 2012
In Millions, unless otherwise specified
Acquired Intangible Assets [Line Items]	'	'
Gross Carrying Amount	$1,473	$1,473
Accumulated Amortization	-632	-541
Net Carrying Amount	841	932
Client relationships [Member]	'	'
Acquired Intangible Assets [Line Items]	'	'
Gross Carrying Amount	1,228	1,228
Accumulated Amortization	-569	-493
Net Carrying Amount	659	735
Technology and content [Member]	'	'
Acquired Intangible Assets [Line Items]	'	'
Gross Carrying Amount	99	99
Accumulated Amortization	-63	-48
Net Carrying Amount	36	51
Trademark license [Member]	'	'
Acquired Intangible Assets [Line Items]	'	'
Gross Carrying Amount	146	146
Accumulated Amortization	'	'
Net Carrying Amount	$146	$146

Goodwill_and_Acquired_Intangib3

Goodwill and Acquired Intangible Assets - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Goodwill And Intangible Assets Disclosure [Abstract]	'	'	'
Amortization expense on acquired intangible assets	$91	$92	$97

Goodwill_and_Acquired_Intangib4

Goodwill and Acquired Intangible Assets - Estimated Future Amortization Expense for Acquired Intangible Assets (Detail) (USD $)	Sep. 30, 2013
In Millions, unless otherwise specified
Goodwill And Intangible Assets Disclosure [Abstract]	'
2014	$90
2015	90
2016	85
2017	76
2018	72
Thereafter (to 2025)	282
Total	$695

Cash_and_Cash_Equivalents_Summ

Cash and Cash Equivalents - Summary of Cash and Cash Equivalents (Detail) (USD $)	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
In Millions, unless otherwise specified
Cash and Cash Equivalents [Line Items]	'	'	'	'
Cash and cash equivalents	$1,062	$915	$1,032	$741
Corporate [Member]	'	'	'	'
Cash and Cash Equivalents [Line Items]	'	'	'	'
Cash and cash equivalents	429	403	'	'
Broker-dealer subsidiaries [Member]	'	'	'	'
Cash and Cash Equivalents [Line Items]	'	'	'	'
Cash and cash equivalents	540	406	'	'
Trust company subsidiary [Member]	'	'	'	'
Cash and Cash Equivalents [Line Items]	'	'	'	'
Cash and cash equivalents	74	95	'	'
Investment advisory subsidiaries [Member]	'	'	'	'
Cash and Cash Equivalents [Line Items]	'	'	'	'
Cash and cash equivalents	$19	$11	'	'

Cash_and_Investments_Segregate2

Cash and Investments Segregated and on Deposit for Regulatory Purposes - Cash and Investments Segregated and on Deposit for Regulatory Purposes (Detail) (USD $)	Sep. 30, 2013	Sep. 30, 2012
In Millions, unless otherwise specified
Restricted Cash and Cash Equivalents Items [Line Items]	'	'
Cash and investments segregated and on deposit for regulatory purposes	$5,894	$4,030
Reverse Repurchase Agreements (Collateralized by U.S. Government Debt Securities) [Member]	'	'
Restricted Cash and Cash Equivalents Items [Line Items]	'	'
Cash and investments segregated and on deposit for regulatory purposes	2,618	2,181
U.S. Government Debt Securities [Member]	'	'
Restricted Cash and Cash Equivalents Items [Line Items]	'	'
Cash and investments segregated and on deposit for regulatory purposes	1,995	1,564
Cash in Demand Deposit Accounts [Member]	'	'
Restricted Cash and Cash Equivalents Items [Line Items]	'	'
Cash and investments segregated and on deposit for regulatory purposes	1,154	179
Cash on Deposit with Futures Commission Merchant [Member]	'	'
Restricted Cash and Cash Equivalents Items [Line Items]	'	'
Cash and investments segregated and on deposit for regulatory purposes	77	96
U.S. Government Debt Securities on Deposit with Futures Commission Merchant [Member]	'	'
Restricted Cash and Cash Equivalents Items [Line Items]	'	'
Cash and investments segregated and on deposit for regulatory purposes	$50	$10

Receivable_from_and_Payable_to2

Receivable from and Payable to Brokers, Dealers and Clearing Organizations - Amounts Receivable from and Payable to Brokers, Dealers and Clearing Organizations (Detail) (USD $)	Sep. 30, 2013	Sep. 30, 2012
In Millions, unless otherwise specified
Receivable:	'	'
Deposits paid for securities borrowed	$1,220	$924
Broker-dealers	9	2
Deposits with clearing organizations	115	177
Securities failed to deliver	4	7
Total	1,348	1,110
Payable:	'	'
Deposits received for securities loaned	1,948	1,940
Broker-dealers	2	3
Clearing organizations	15	'
Securities failed to receive	8	49
Total	$1,973	$1,992

Allowance_for_Doubtful_Account2

Allowance for Doubtful Accounts on Receivables - Allowance for Doubtful Accounts on Client and Other Receivables (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Valuation And Qualifying Accounts [Abstract]	'	'	'
Beginning balance	$21	$18	$11
Provision for (recovery of) doubtful accounts, net	-1	9	9
Write-off of doubtful accounts	-5	-6	-2
Ending balance	$15	$21	$18

Investments_AvailableForSale_A

Investments Available-For-Sale - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended	1 Months Ended
In Millions, except Share data, unless otherwise specified	Feb. 28, 2013	Sep. 30, 2012	Jul. 31, 2013	Sep. 30, 2013
			Class A common stock [Member]	Class A common stock [Member]
Schedule of Available-for-sale Securities [Line Items]	'	'	'	'
Company's investment shares of Knight Capital Group	'	39,000	'	'
Convertible preferred shares	'	2.00%	'	'
Convertible shares of Knight Class A common stock	'	666.667	'	'
Conversion of preferred stock into Knight Class A common stock	26,000,000	'	'	'
Aggregate fair value of merger consideration received	'	'	$95	'
Amount paid in cash for convertible common shares	'	'	69	'
Common stock received	'	'	2,500,000	'
Common stock surrendered, approximate fair value	'	'	26	'
Approximate pre-tax gain on investment	'	'	$54	'
Investment in shares of Knight Capital Group	'	'	'	1,500,000

Property_and_Equipment_Schedul

Property and Equipment - Schedule of Property and Equipment (Detail) (USD $)	Sep. 30, 2013	Sep. 30, 2012
In Millions, unless otherwise specified
Property Plant And Equipment [Abstract]	'	'
Computer equipment	$205	$190
Building and building components	198	'
Building construction in process	'	164
Leasehold improvements	148	147
Software	144	117
Land	17	13
Other property and equipment	67	48
Property and equipment, gross	779	679
Less: Accumulated depreciation and amortization	-282	-235
Property and equipment, net	$497	$444

Longterm_Debt_and_Credit_Facil2

Long-term Debt and Credit Facilities - Schedule of Long-term Debt (Detail) (USD $)

Sep. 30, 2013

Sep. 30, 2012

Nov. 25, 2009

Nov. 25, 2009

Nov. 25, 2009

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2012

In Millions, unless otherwise specified

4.150% Senior Notes due 2014 [Member]

5.600% Senior Notes due 2019 [Member]

2.950% Senior Notes due 2012 [Member]

Senior Notes [Member]

Senior Notes [Member]

Senior Notes [Member]

Senior Notes [Member]

Senior Notes [Member]

Senior Notes [Member]

Senior Notes [Member]

4.150% Senior Notes due 2014 [Member]

4.150% Senior Notes due 2014 [Member]

5.600% Senior Notes due 2019 [Member]

5.600% Senior Notes due 2019 [Member]

2.950% Senior Notes due 2012 [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

Face Value

$1,000

'

$500

$500

$250

$1,000

$1,250

$500

$500

$500

$500

$250

Unamortized Discount

'

'

'

'

'

'

-1

'

'

'

-1

'

Fair Value Adjustment

'

'

'

'

'

52

96

15

27

37

68

1

Net Carrying Value

$1,052

$1,345

'

'

'

$1,052

$1,345

$515

$527

$537

$567

$251

Longterm_Debt_and_Credit_Facil3

Long-term Debt and Credit Facilities - Fiscal Year Maturities on Long-term Debt Outstanding (Detail) (USD $)	Sep. 30, 2013
In Millions, unless otherwise specified
Debt Disclosure [Abstract]	'
2014	'
2015	500
2016	'
2017	'
2018	'
Thereafter	500
Total	$1,000

Longterm_Debt_and_Credit_Facil4

Long-term Debt and Credit Facilities - Senior Notes - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Nov. 25, 2009
Debt Instrument [Line Items]	'	'
Aggregate principal amount of unsecured Senior Notes issued	1,000	'
Senior Notes [Member]	'	'
Debt Instrument [Line Items]	'	'
Aggregate principal amount of unsecured Senior Notes issued	'	1,250
Issue of Senior Notes at Aggregate Discount	'	1
Senior Notes redemption price in percentage based on principal amount of Note	100.00%	'
2.950% Senior Notes due 2012 [Member]	'	'
Debt Instrument [Line Items]	'	'
Aggregate principal amount of unsecured Senior Notes issued	'	250
Due date of Senior Notes	1-Dec-12	'
Debt instrument interest rate stated percentage	2.95%	'
4.150% Senior Notes due 2014 [Member]	'	'
Debt Instrument [Line Items]	'	'
Aggregate principal amount of unsecured Senior Notes issued	'	500
Due date of Senior Notes	1-Dec-14	'
Debt instrument interest rate stated percentage	4.15%	'
Discount rate for redemption of Senior Notes principal and interest, comparable to U.S. Treasury rate plus basis points	0.30%	'
5.600% Senior Notes due 2019 [Member]	'	'
Debt Instrument [Line Items]	'	'
Aggregate principal amount of unsecured Senior Notes issued	'	$500
Due date of Senior Notes	1-Dec-19	'
Debt instrument interest rate stated percentage	5.60%	'
Discount rate for redemption of Senior Notes principal and interest, comparable to U.S. Treasury rate plus basis points	0.35%	'

Longterm_Debt_and_Credit_Facil5

Long-term Debt and Credit Facilities - Interest Rate Swaps - Additional Information (Detail) (USD $)	Sep. 30, 2013	Sep. 30, 2012	Dec. 30, 2009	Dec. 30, 2009	Jan. 07, 2011	Sep. 30, 2013
In Millions, unless otherwise specified	Cash [Member]	Cash [Member]	2.950% Senior Notes due 2012 [Member]	4.150% Senior Notes due 2014 [Member]	5.600% Senior Notes due 2019 [Member]	Senior Notes [Member]
			Interest Rate Swaps [Member]	Interest Rate Swaps [Member]	Interest Rate Swaps [Member]
Debt Instrument [Line Items]	'	'	'	'	'	'
Notional amount of interest rate swaps on Notes	'	'	$250	$500	$500	'
Interest rate swap, variable rate basis	'	'	'Three-month LIBOR	'Three-month LIBOR	'Three-month LIBOR	'
Variable interest rate on swaps in excess of LIBOR rate, percentage	'	'	0.97%	1.25%	2.37%	'
Weighted-average effective interest rate	'	'	'	'	'	2.07%
Pledged collateral from the interest rate swap counterparty	$67	$113	'	'	'	'

Longterm_Debt_and_Credit_Facil6

Long-term Debt and Credit Facilities - Gains and Losses Resulting from Changes in Fair Value of Interest Rate Swaps and Hedged Fixed Rate Debt (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Debt Disclosure [Abstract]	'	'	'
Gain (loss) on fair value of interest rate swaps	($44)	$8	$39
Gain (loss) on fair value of hedged fixed-rate debt	44	-8	-39
Net gain (loss) recorded in interest on borrowings	'	'	'

Longterm_Debt_and_Credit_Facil7

Long-term Debt and Credit Facilities - Fair Value of Outstanding Derivatives Designated as Hedging Instruments (Detail) (USD $)	Sep. 30, 2013	Sep. 30, 2012
In Millions, unless otherwise specified
Derivatives recorded under the caption Other assets:	'	'
Interest rate swap assets	$52	$96

Longterm_Debt_and_Credit_Facil8

Long-term Debt and Credit Facilities - TD Ameritrade Holding Corporation and Clearing, Inc Credit Agreement - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended
	Dec. 28, 2012	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 28, 2011
Debt Instrument [Line Items]	'	'	'	'	'
Amount borrowed under Senior unsecured revolving credit facility	'	$275,000,000	'	'	'
TD Ameritrade Holding Corporation [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Amount borrowed under Senior unsecured revolving credit facility	'	275,000,000	'	'	'
Senior Unsecured Revolving Credit Facility [Member] | TD Ameritrade Holding Corporation [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Senior unsecured revolving credit facility, aggregate principal amount	'	'	'	'	300,000,000
Line of credit facility expiration date	'	28-Jun-14	'	'	'
Amount borrowed under Senior unsecured revolving credit facility	275,000,000	'	'	'	'
Borrowings outstanding under the Revolving Credit Facility	'	0	'	0	'
Per share special cash dividend paid on common stock	'	'	$0.50	'	'
Interest rate under revolving facility option one	'	'LIBOR plus an interest rate margin (bParent LIBOR loansb)	'	'	'
Interest Rate Under Revolving Facility Option Two	'	'(i)B the highest of (x)B the prime rate, (y)B the federal funds effective rate plus 0.50% or (z)B one-month LIBOR plus 1.00%, plus (ii)B an interest rate margin (bBase Rate loansb)	'	'	'
Commitment fee percentage	'	0.15%	'	'	'
Commitment fees range	'	'From 0.15% to 0.375%	'	'	'
Senior Unsecured Revolving Credit Facility [Member] | TD Ameritrade Holding Corporation [Member] | Minimum [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Commitment fee percentage	'	0.15%	'	'	'
Senior Unsecured Revolving Credit Facility [Member] | TD Ameritrade Holding Corporation [Member] | Maximum [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Commitment fee percentage	'	0.38%	'	'	'
Senior Unsecured Revolving Credit Facility [Member] | TD Ameritrade Holding Corporation [Member] | Federal Funds Rate [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Interest rate margin	'	0.50%	'	'	'
Senior Unsecured Revolving Credit Facility [Member] | TD Ameritrade Holding Corporation [Member] | One Month LIBOR [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Interest rate margin	'	1.00%	'	'	'
Senior Unsecured Revolving Credit Facility [Member] | TD Ameritrade Holding Corporation [Member] | LIBOR [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Interest rate margin	'	1.25%	'	'	'
Senior Unsecured Revolving Credit Facility [Member] | TD Ameritrade Holding Corporation [Member] | LIBOR [Member] | Minimum [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Interest rate margin	'	1.25%	'	'	'
Senior Unsecured Revolving Credit Facility [Member] | TD Ameritrade Holding Corporation [Member] | LIBOR [Member] | Maximum [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Interest rate margin	'	2.25%	'	'	'
Senior Unsecured Revolving Credit Facility [Member] | TD Ameritrade Holding Corporation [Member] | Base Rate [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Interest rate margin	'	0.25%	'	'	'
Senior Unsecured Revolving Credit Facility [Member] | TD Ameritrade Holding Corporation [Member] | Base Rate [Member] | Minimum [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Interest rate margin	'	0.25%	'	'	'
Senior Unsecured Revolving Credit Facility [Member] | TD Ameritrade Holding Corporation [Member] | Base Rate [Member] | Maximum [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Interest rate margin	'	1.25%	'	'	'
Senior Unsecured Revolving Credit Facility [Member] | TD Ameritrade Clearing, Inc. [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Senior unsecured revolving credit facility, aggregate principal amount	'	'	'	'	300,000,000
Line of credit facility expiration date	'	28-Jun-14	'	'	'
Borrowings outstanding under the Revolving Credit Facility	'	$0	'	$0	'
Interest rate under revolving facility option one	'	'LIBOR plus an interest rate margin (bTDAC LIBOR loansb)	'	'	'
Interest Rate Under Revolving Facility Option Two	'	'The federal funds effective rate plus an interest rate margin (bFed Funds Rate loansb)	'	'	'
Commitment fee percentage	'	0.13%	'	'	'
Commitment fees range	'	'From 0.125% to 0.30%	'	'	'
Senior Unsecured Revolving Credit Facility [Member] | TD Ameritrade Clearing, Inc. [Member] | Minimum [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Commitment fee percentage	'	0.13%	'	'	'
Senior Unsecured Revolving Credit Facility [Member] | TD Ameritrade Clearing, Inc. [Member] | Maximum [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Commitment fee percentage	'	0.30%	'	'	'
Senior Unsecured Revolving Credit Facility [Member] | TD Ameritrade Clearing, Inc. [Member] | Federal Funds Rate [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Interest rate margin	'	1.00%	'	'	'
Senior Unsecured Revolving Credit Facility [Member] | TD Ameritrade Clearing, Inc. [Member] | Federal Funds Rate [Member] | Minimum [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Interest rate margin	'	1.00%	'	'	'
Senior Unsecured Revolving Credit Facility [Member] | TD Ameritrade Clearing, Inc. [Member] | Federal Funds Rate [Member] | Maximum [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Interest rate margin	'	2.00%	'	'	'
Senior Unsecured Revolving Credit Facility [Member] | TD Ameritrade Clearing, Inc. [Member] | LIBOR [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Interest rate margin	'	1.00%	'	'	'
Senior Unsecured Revolving Credit Facility [Member] | TD Ameritrade Clearing, Inc. [Member] | LIBOR [Member] | Minimum [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Interest rate margin	'	1.00%	'	'	'
Senior Unsecured Revolving Credit Facility [Member] | TD Ameritrade Clearing, Inc. [Member] | LIBOR [Member] | Maximum [Member]	'	'	'	'	'
Debt Instrument [Line Items]	'	'	'	'	'
Interest rate margin	'	2.00%	'	'	'

Income_Taxes_Provision_for_Inc

Income Taxes - Provision for Income Taxes (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Current expense :	'	'	'
Federal	$370	$314	$357
State	33	1	20
Total	403	315	377
Deferred expense (benefit):	'	'	'
Federal	-2	-2	-5
State	12	7	7
Total	10	5	2
Provision for income taxes	$413	$320	$379

Income_Taxes_Reconciliation_of

Income Taxes - Reconciliation of Federal Statutory Tax Rate to Effective Tax Rate (Detail)	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Income Tax Disclosure [Abstract]	'	'	'
Federal statutory rate	35.00%	35.00%	35.00%
State taxes, net of federal tax effect	2.60%	2.10%	2.30%
Adjustments to estimated state income taxes	0.40%	0.10%	-0.10%
Interest recorded on unrecognized tax benefits, net	0.30%	0.10%	0.50%
Reversal of accruals for unrecognized tax benefits	-0.30%	-1.70%	-0.50%
Reversal of capital loss valuation allowance	'	-0.40%	'
Other	'	0.10%	0.10%
Effective income tax rate	38.00%	35.30%	37.30%

Income_Taxes_Additional_Inform

Income Taxes - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
Income Taxes [Line Items]	'	'	'	'
Effective income tax rate	38.00%	35.30%	37.30%	'
Favorable resolutions of certain income tax matters	$6	$19	$6	'
Benefit from reversal of valuation allowance related to capital loss carryover	'	3	'	'
Favorable per share impact on earnings	'	$0.04	$0.01	'
Favorable deferred income tax adjustments	'	'	1	'
Unfavorable deferred income tax adjustments	4	'	'	'
Deferred tax benefits relating to intangible asset amortization deductions	1	2	'	'
Federal net operating loss carryover acquired in thinkorswim acquisition	3	'	'	'
Federal net operating loss carryover acquired in thinkorswim acquisition, expiration year	'2019	'	'	'
Subsidiaries state operating loss carryforwards	340	'	'	'
Decrease in the valuation allowance	19	'	'	'
Unrecognized tax benefits	137	139	145	149
Unrecognized tax benefits net of federal benefit on state matters	89	91	'	'
Unrecognized tax benefits net of federal benefit on state matters that would impact effective tax rate	89	89	'	'
Statute of Limitations Period, Minimum (In years)	'3 years	'	'	'
Statute of Limitations Period, Maximum (In years)	'4 years	'	'	'
Reasonably possible reduction in unrecognized tax benefits	40	'	'	'
Reasonably possible reduction in unrecognized tax benefits net of federal benefit on state matters	26	'	'	'
Interest and penalties expense (benefit) recognized	2	-3	5	'
Accrued interest and penalties related to unrecognized tax benefits	$48	$44	'	'
Minimum [Member]	'	'	'	'
Income Taxes [Line Items]	'	'	'	'
Subsidiaries state operating loss carryforwards, expiration year	'2014	'	'	'
Federal return years that remain open under the statute of limitations	'2010	'	'	'
Maximum [Member]	'	'	'	'
Income Taxes [Line Items]	'	'	'	'
Subsidiaries state operating loss carryforwards, expiration year	'2032	'	'	'
Federal return years that remain open under the statute of limitations	'2012	'	'	'

Income_Taxes_Deferred_Tax_Asse

Income Taxes - Deferred Tax Assets (Liabilities) (Detail) (USD $)	Sep. 30, 2013	Sep. 30, 2012
In Millions, unless otherwise specified
Deferred tax assets:	'	'
Accrued liabilities	$72	$69
Intangible assets, state tax benefit	12	15
Stock-based compensation	36	30
Allowance for doubtful accounts	6	8
Unrealized tax gain on IDA agreement	'	9
Operating loss carryforwards	21	40
Other deferred tax assets	3	6
Gross deferred tax assets	150	177
Less: Valuation allowance	-18	-37
Net deferred tax assets	132	140
Deferred tax liabilities:	'	'
Property and intangible assets	-478	-478
Unrealized investment gains	'	-10
Other deferred tax liabilities	-5	-4
Total deferred tax liabilities	-483	-492
Net deferred tax liabilities	($351)	($352)

Income_Taxes_Reconciliation_of1

Income Taxes - Reconciliation of Activity Related to Unrecognized Tax Benefits (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Income Tax Disclosure [Abstract]	'	'	'
Beginning balance	$139	$145	$149
Additions based on tax positions related to the current year	8	10	10
Additions for tax positions of prior years	2	8	7
Reductions for tax positions of prior years	-5	-3	-12
Reductions due to settlements with taxing authorities	-1	-5	-1
Reductions due to lapsed statute of limitations	-6	-16	-8
Ending balance	$137	$139	$145

Capital_Requirements_Additiona

Capital Requirements - Additional Information (Detail) (USD $)	Sep. 30, 2013	Sep. 30, 2012
Net Capital and Net Capital Requirements For Company's Broker Dealer Subsidiaries [Line Items]	'	'
Percentage of net capital to aggregate debit balances required for a broker-dealer to repay subordinated borrowings, pay cash dividends, or make any unsecured advances or loans to its parent company or employees	5.00%	'
Percentage of net capital to the Company's risk based capital requirement required for a broker-dealer to repay subordinated borrowings, pay cash dividends, or make any unsecured advances or loans to its parent company or employees	110.00%	'
Percentage of net capital to the Company's minimum dollar requirement required for a broker-dealer to repay subordinated borrowings, pay cash dividends, or make any unsecured advances or loans to its parent company or employees	120.00%	'
TD Ameritrade Trust Company's Tier 1 capital	$23,000,000	$20,000,000
Amount in excess of required Tier 1 capital	8,000,000	10,000,000
TD Ameritrade Clearing, Inc. [Member]	'	'
Net Capital and Net Capital Requirements For Company's Broker Dealer Subsidiaries [Line Items]	'	'
Minimum net capital required	1,500,000	'
Percentage of aggregate debit balances required as minimum net capital	2.00%	'
TD Ameritrade, Inc. [Member]	'	'
Net Capital and Net Capital Requirements For Company's Broker Dealer Subsidiaries [Line Items]	'	'
Minimum net capital required	250,000	'
Percentage of aggregate debit balances required as minimum net capital	2.00%	'
Net capital required under Regulation 1.17 of the Commodity Exchange Act	$1,000,000	'
Minimum percentage of the total risk margin requirements for all positions carried in non-client accounts to be added to the minimum percentage of the total risk margin requirements for all positions carried in client accounts for minimum net capital calculation	8.00%	'
Minimum percentage of the total risk margin requirements for all positions carried in client accounts to be added to the minimum percentage of the total risk margin requirements for all positions carried in non-client accounts for minimum net capital calculation	8.00%	'

Capital_Requirements_Net_Capit

Capital Requirements - Net Capital and Net Capital Requirements for Company's Broker-dealer Subsidiaries (Detail) (USD $)	Sep. 30, 2013	Sep. 30, 2012
In Millions, unless otherwise specified
TD Ameritrade Clearing, Inc. [Member]	'	'
Net Capital and Net Capital Requirements For Company's Broker Dealer Subsidiaries [Line Items]	'	'
Net Capital	$1,302	$1,302
Required Net Capital	222	203
Net Capital in Excess of Required Net Capital	1,080	1,099
Net Capital in Excess of Early Warning Threshold	746	796
Ratio of Net Capital to Aggregate Debit Balances	11.70%	12.86%
TD Ameritrade, Inc. [Member]	'	'
Net Capital and Net Capital Requirements For Company's Broker Dealer Subsidiaries [Line Items]	'	'
Net Capital	305	261
Required Net Capital	10	8
Net Capital in Excess of Required Net Capital	295	253
Net Capital in Excess of Early Warning Threshold	$294	$252

Stockbased_Compensation_Additi

Stock-based Compensation - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
	Plans
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Number of stock incentive plans	2	'	'
Expiration period of stock options from grant date	'10 years	'	'
Stock-based compensation expense	$29	$41	$35
Income tax benefits	11	15	13
Total intrinsic value of options exercised	65	21	10
Number of options granted	0	0	0
Unrecognized compensation cost related to nonvested stock option awards	0	'	'
Stock Options [Member] | Minimum [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Vesting period	'1 year	'	'
Stock Options [Member] | Maximum [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Vesting period	'4 years	'	'
Restricted Stock Units (RSUs) [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Total unrecognized compensation costs related to nonvested stock-based compensation awards	$27	'	'
Weighted average period of recognition of unrecognized compensation cost related to nonvested stock-based compensation awards	'1 year 9 months 18 days	'	'
Restricted Stock Units (RSUs) [Member] | Employees [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Vesting period	'3 years	'	'
Restricted Stock Units (RSUs) [Member] | Non-employee directors [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Vesting period	'1 year	'	'
Long-Term Incentive Plan [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Company's common stock reserved for issuance to employee	42,104,174	'	'
2006 Directors Incentive Plan [Member]	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'
Company's common stock reserved for issuance to employee	1,830,793	'	'

Stockbased_Compensation_Summar

Stock-based Compensation - Summary of Option Activity in Stock Incentive Plans (Detail) (USD $)	12 Months Ended
In Millions, except Share data in Thousands, unless otherwise specified	Sep. 30, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Number of Options, Outstanding at beginning of year	7,190
Number of Options, Exercised	-4,600
Number of Options, Expired	-47
Number of Options, Outstanding at end of year	2,543
Number of Options, Exercisable at end of year	2,515
Weighted Average Exercise Price, Outstanding at beginning of year	$9.31
Weighted Average Exercise Price, Exercised	$4.13
Weighted Average Exercise Price, Expired	$26.52
Weighted Average Exercise Price, Outstanding at end of year	$18.36
Weighted Average Exercise Price, Exercisable at end of year	$18.34
Weighted Average Remaining Contractual Term, Outstanding at end of year	'5 years 1 month 6 days
Weighted Average Remaining Contractual Term, Exercisable at end of year	'5 years 1 month 6 days
Aggregate Intrinsic Value, Outstanding at end of year	$20
Aggregate Intrinsic Value, Exercisable at end of year	$20

Stockbased_Compensation_Summar1

Stock-based Compensation - Summary of Restricted Stock Units Activity in Stock Incentive Plans (Detail) (USD $)	12 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]	'
Number of units, Nonvested at beginning of year	4,139
Number of units, Granted	2,172
Number of Units, Dividend equivalents	235
Number of Units, Vested	-861
Number of Units, Forfeited	-334
Number of units, Nonvested at end of year	5,351
Weighted Average Grant Date Fair Value, Nonvested at beginning of year	$17.74
Weighted Average Grant Date Fair Value, Granted	$16.38
Weighted Average Grant Date Fair Value, Dividend equivalents	$16.92
Weighted Average Grant Date Fair Value, Vested	$19.13
Weighted Average Grant Date Fair Value, Forfeited	$17.15
Weighted Average Grant Date Fair Value, Nonvested at end of year	$17

Employee_Benefit_Plans_Additio

Employee Benefit Plans - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Compensation And Retirement Disclosure [Abstract]	'	'	'
Profit-sharing and matching contributions expense	$28	$28	$31

Earnings_Per_Share_Computation

Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Detail) (USD $)	3 Months Ended								12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Earnings Per Share [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Net income	$200	$184	$144	$147	$143	$154	$137	$152	$675	$586	$638
Weighted average shares outstanding - basic	'	'	'	'	'	'	'	'	549	548	570
Effect of dilutive securities:	'	'	'	'	'	'	'	'	'	'	'
Common stock equivalent shares related to stock-based compensation	'	'	'	'	'	'	'	'	5	6	6
Weighted average shares outstanding - diluted	'	'	'	'	'	'	'	'	554	554	576
Earnings per share - basic	$0.36	$0.33	$0.26	$0.27	$0.26	$0.28	$0.25	$0.28	$1.23	$1.07	$1.12
Earnings per share - diluted	$0.36	$0.33	$0.26	$0.27	$0.26	$0.28	$0.25	$0.27	$1.22	$1.06	$1.11

Earnings_Per_Share_Computation1

Earnings Per Share - Computation of Basic and Diluted Earnings Per Share (Parenthetical) (Detail)	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Earnings Per Share [Abstract]	'	'	'
Antidilutive shares excluded from the calculation of diluted EPS	0.7	2.5	1.5

Commitments_and_Contingencies_1

Commitments and Contingencies - Future Minimum Rental Commitments Under Non-Cancelable Operating Leases (Detail) (USD $)	Sep. 30, 2013
In Millions, unless otherwise specified
Commitments And Contingencies Disclosure [Abstract]	'
Minimum Lease Payments 2014	$52
Minimum Lease Payments 2015	48
Minimum Lease Payments 2016	45
Minimum Lease Payments 2017	45
Minimum Lease Payments 2018	42
Minimum Lease Payments Thereafter (to 2029)	109
Total Minimum Lease Payments	341
Sublease Income 2014	-1
Sublease Income 2015	-1
Sublease Income 2016	-1
Sublease Income 2017	-2
Sublease Income 2018	-1
Sublease Income Thereafter (to 2029)	-1
Total Sublease Income	-7
Net Lease Commitments 2014	51
Net Lease Commitments 2015	47
Net Lease Commitments 2016	44
Net Lease Commitments 2017	43
Net Lease Commitments 2018	41
Net Lease Commitments Thereafter (to 2029)	108
Total Net Lease Commitments	$334

Commitments_and_Contingencies_2

Commitments and Contingencies - Additional Information (Detail) (USD $)	1 Months Ended	12 Months Ended
	Feb. 28, 2011	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2008	Jan. 27, 2011	Jul. 23, 2010
Contingencies And Commitments [Line Items]	'	'	'	'	'	'	'
Rental expense, net of sublease income	'	$54,000,000	$50,000,000	$50,000,000	'	'	'
Per share net asset value of the Reserve Yield Plus Fund	'	'	'	'	'Below $1.00 per share	'	'
Yield Plus Fund's stated objective to maintain a per share net asset value	'	'	'	'	$1	'	'
Approximate percentage of the Yield Plus Fund assets which have been distributed	'	'	'	'	'	'	94.80%
Approximate remaining total assets in Yield Plus Fund	'	'	'	'	'	'	39,700,000
Approximate percentage of Yield Plus Fund held by TD Ameritrade, Inc. clients	'	79.00%	'	'	'	'	'
Per share amount payable to all eligible clients that purchased shares of the yield plus fund and continued to own those shares	'	'	'	'	'	$0.01	'
Amount paid to clients under the SEC yield plus fund settlement agreement	10,000,000	'	'	'	'	'	'
Company's estimate of its clients current aggregate shortfall in the Yield Plus Fund	'	36,000,000	'	'	'	'	'
Contingent liability for guarantees to securities clearinghouses and exchanges	'	0	'	'	'	'	'
Minimum [Member]	'	'	'	'	'	'	'
Contingencies And Commitments [Line Items]	'	'	'	'	'	'	'
Aggregate range of reasonably possible losses in excess of amounts accrued	'	0	'	'	'	'	'
Maximum [Member]	'	'	'	'	'	'	'
Contingencies And Commitments [Line Items]	'	'	'	'	'	'	'
Aggregate range of reasonably possible losses in excess of amounts accrued	'	$50,000,000	'	'	'	'	'

Commitments_and_Contingencies_3

Commitments and Contingencies - Collateral Available, Loaned or Repledged (Detail) (USD $)	Sep. 30, 2013	Sep. 30, 2012
In Billions, unless otherwise specified
Commitments And Contingencies Disclosure [Abstract]	'	'
Client margin securities	$12.50	$12
Stock borrowings	1.2	0.9
Total collateral available	13.7	12.9
Collateral loaned	1.9	1.9
Collateral repledged	1.8	1.2
Total collateral loaned or repledged	$3.70	$3.10

Commitments_and_Contingencies_4

Commitments and Contingencies - Summary of Cash Deposited with and Securities Pledged to Clearinghouses (Detail) (USD $)	Sep. 30, 2013	Sep. 30, 2012
In Millions, unless otherwise specified
Cash Deposited with and Securities Pledged to Clearinghouses [Line Items]	'	'
Cash deposited and securities pledged	$176	$177
Cash [Member]	'	'
Cash Deposited with and Securities Pledged to Clearinghouses [Line Items]	'	'
Cash deposited and securities pledged	115	121
U.S. Government Debt Securities [Member]	'	'
Cash Deposited with and Securities Pledged to Clearinghouses [Line Items]	'	'
Cash deposited and securities pledged	$61	$56

Fair_Value_Disclosures_Additio

Fair Value Disclosures - Additional Information (Detail) (USD $)	12 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
Fair Value Disclosures [Abstract]	'	'
Net Asset Value per share of money market and other mutual funds, before decline in value	$1	'
Company's investment shares of Knight Capital Group	'	39,000
Convertible preferred shares	'	2.00%
Convertible shares of Knight Class A common stock	'	666.667
Minimum range of occurrence of auction process	'7 days	'
Maximum range of occurrence of auction process	'35 days	'
Maximum range of cash and cash equivalents original maturity	'3 months	'
Reverse repurchase agreements generally have a maturity	'7 days	'
Aggregate estimated fair value of the Senior Notes	$1,100	$1,373
Long-term debt	$1,052	$1,345

Fair_Value_Disclosures_Fair_Va

Fair Value Disclosures - Fair Value Hierarchy for Assets and Liabilities Measured on Recurring Basis (Detail) (USD $)	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
In Millions, unless otherwise specified
Assets:	'	'	'	'
Cash equivalents	$1,062	$915	$1,032	$741
Short-term investments available-for-sale	4	154	'	'
Cash and investments segregated and on deposit for regulatory purposes	5,894	4,030	'	'
Securities owned	323	343	'	'
Investments available-for-sale	13	70	'	'
Other assets	52	96	'	'
Fair Value, Measurements, Recurring [Member]	'	'	'	'
Assets:	'	'	'	'
Cash equivalents	'	818	'	'
Securities owned	323	343	'	'
Total assets at fair value	3,406	3,055	'	'
Fair Value, Measurements, Recurring [Member] | Money Market Mutual Funds [Member]	'	'	'	'
Assets:	'	'	'	'
Cash equivalents	969	768	'	'
Fair Value, Measurements, Recurring [Member] | U.S. Government Debt Securities [Member]	'	'	'	'
Assets:	'	'	'	'
Cash equivalents	'	50	'	'
Short-term investments available-for-sale	4	154	'	'
Cash and investments segregated and on deposit for regulatory purposes	2,045	1,574	'	'
Securities owned	313	333	'	'
Fair Value, Measurements, Recurring [Member] | Auction Rate Securities [Member]	'	'	'	'
Assets:	'	'	'	'
Securities owned	5	6	'	'
Fair Value, Measurements, Recurring [Member] | Money Market and Other Mutual Funds [Member]	'	'	'	'
Assets:	'	'	'	'
Securities owned	1	1	'	'
Fair Value, Measurements, Recurring [Member] | Other Securities [Member]	'	'	'	'
Assets:	'	'	'	'
Securities owned	4	3	'	'
Fair Value, Measurements, Recurring [Member] | Convertible Preferred Equity Securities [Member]	'	'	'	'
Assets:	'	'	'	'
Investments available-for-sale	'	70	'	'
Fair Value, Measurements, Recurring [Member] | Interest Rate Swaps [Member]	'	'	'	'
Assets:	'	'	'	'
Other assets	52	96	'	'
Fair Value, Measurements, Recurring [Member] | Equity Securities [Member]	'	'	'	'
Assets:	'	'	'	'
Investments available-for-sale	13	'	'	'
Liabilities:	'	'	'	'
Securities sold, not yet purchased	13	3	'	'
Level 1 [Member] | Fair Value, Measurements, Recurring [Member]	'	'	'	'
Assets:	'	'	'	'
Cash equivalents	'	768	'	'
Securities owned	1	1	'	'
Total assets at fair value	983	769	'	'
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Money Market Mutual Funds [Member]	'	'	'	'
Assets:	'	'	'	'
Cash equivalents	969	768	'	'
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | U.S. Government Debt Securities [Member]	'	'	'	'
Assets:	'	'	'	'
Cash equivalents	'	'	'	'
Short-term investments available-for-sale	'	'	'	'
Cash and investments segregated and on deposit for regulatory purposes	'	'	'	'
Securities owned	'	'	'	'
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Auction Rate Securities [Member]	'	'	'	'
Assets:	'	'	'	'
Securities owned	'	'	'	'
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Money Market and Other Mutual Funds [Member]	'	'	'	'
Assets:	'	'	'	'
Securities owned	'	'	'	'
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Other Securities [Member]	'	'	'	'
Assets:	'	'	'	'
Securities owned	1	1	'	'
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Convertible Preferred Equity Securities [Member]	'	'	'	'
Assets:	'	'	'	'
Investments available-for-sale	'	'	'	'
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Interest Rate Swaps [Member]	'	'	'	'
Assets:	'	'	'	'
Other assets	'	'	'	'
Level 1 [Member] | Fair Value, Measurements, Recurring [Member] | Equity Securities [Member]	'	'	'	'
Assets:	'	'	'	'
Investments available-for-sale	13	'	'	'
Liabilities:	'	'	'	'
Securities sold, not yet purchased	13	3	'	'
Level 2 [Member] | Fair Value, Measurements, Recurring [Member]	'	'	'	'
Assets:	'	'	'	'
Cash equivalents	'	50	'	'
Securities owned	316	335	'	'
Total assets at fair value	2,417	2,279	'	'
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Money Market Mutual Funds [Member]	'	'	'	'
Assets:	'	'	'	'
Cash equivalents	'	'	'	'
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | U.S. Government Debt Securities [Member]	'	'	'	'
Assets:	'	'	'	'
Cash equivalents	'	50	'	'
Short-term investments available-for-sale	4	154	'	'
Cash and investments segregated and on deposit for regulatory purposes	2,045	1,574	'	'
Securities owned	313	333	'	'
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Auction Rate Securities [Member]	'	'	'	'
Assets:	'	'	'	'
Securities owned	'	'	'	'
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Money Market and Other Mutual Funds [Member]	'	'	'	'
Assets:	'	'	'	'
Securities owned	'	'	'	'
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Other Securities [Member]	'	'	'	'
Assets:	'	'	'	'
Securities owned	3	2	'	'
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Convertible Preferred Equity Securities [Member]	'	'	'	'
Assets:	'	'	'	'
Investments available-for-sale	'	70	'	'
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Interest Rate Swaps [Member]	'	'	'	'
Assets:	'	'	'	'
Other assets	52	96	'	'
Level 2 [Member] | Fair Value, Measurements, Recurring [Member] | Equity Securities [Member]	'	'	'	'
Assets:	'	'	'	'
Investments available-for-sale	'	'	'	'
Liabilities:	'	'	'	'
Securities sold, not yet purchased	'	'	'	'
Level 3 [Member] | Fair Value, Measurements, Recurring [Member]	'	'	'	'
Assets:	'	'	'	'
Cash equivalents	'	'	'	'
Securities owned	6	7	'	'
Total assets at fair value	6	7	'	'
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Money Market Mutual Funds [Member]	'	'	'	'
Assets:	'	'	'	'
Cash equivalents	'	'	'	'
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | U.S. Government Debt Securities [Member]	'	'	'	'
Assets:	'	'	'	'
Cash equivalents	'	'	'	'
Short-term investments available-for-sale	'	'	'	'
Cash and investments segregated and on deposit for regulatory purposes	'	'	'	'
Securities owned	'	'	'	'
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Auction Rate Securities [Member]	'	'	'	'
Assets:	'	'	'	'
Securities owned	5	6	'	'
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Money Market and Other Mutual Funds [Member]	'	'	'	'
Assets:	'	'	'	'
Securities owned	1	1	'	'
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Other Securities [Member]	'	'	'	'
Assets:	'	'	'	'
Securities owned	'	'	'	'
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Convertible Preferred Equity Securities [Member]	'	'	'	'
Assets:	'	'	'	'
Investments available-for-sale	'	'	'	'
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Interest Rate Swaps [Member]	'	'	'	'
Assets:	'	'	'	'
Other assets	'	'	'	'
Level 3 [Member] | Fair Value, Measurements, Recurring [Member] | Equity Securities [Member]	'	'	'	'
Assets:	'	'	'	'
Investments available-for-sale	'	'	'	'
Liabilities:	'	'	'	'
Securities sold, not yet purchased	'	'	'	'

Fair_Value_Disclosures_Changes

Fair Value Disclosures - Changes in Level 3 Assets And Liabilities Measured on Recurring Basis (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Auction Rate Securities [Member]	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'	'
Balance, beginning of year	$6	$20	$209
Purchases	'	1	'
Net gains included in earnings	'	'	5
Sales	'	-2	'
Purchases, sales, issuances and settlements, net	'	'	-194
Settlements	-1	-13	'
Balance, end of year	5	6	20
Money Market and Other Mutual Funds [Member]	'	'	'
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]	'	'	'
Balance, beginning of year	1	1	5
Purchases	'	'	'
Net gains included in earnings	'	'	'
Sales	'	'	'
Purchases, sales, issuances and settlements, net	'	'	-4
Settlements	'	'	'
Balance, end of year	$1	$1	$1

Fair_Value_Disclosures_Quantit

Fair Value Disclosures - Quantitative Information about Level 3 Unobservable Inputs (Detail) (Auction Rate Securities [Member])	12 Months Ended
	Sep. 30, 2013	Sep. 30, 2012
Fair Value, Option, Quantitative Disclosures [Line Items]	'	'
Asset	'Auction Rate Securities	'Auction Rate Securities
Valuation Technique	'Discounted cash flow	'Discounted cash flow
Yield premium for illiquidity	2.00%	2.00%
Weighted Average [Member]	'	'
Fair Value, Option, Quantitative Disclosures [Line Items]	'	'
Constant prepayment rate (Annual)	15.00%	17.00%
Yield premium for illiquidity	2.00%	2.00%
Minimum [Member]	'	'
Fair Value, Option, Quantitative Disclosures [Line Items]	'	'
Constant prepayment rate (Annual)	10.00%	15.00%
Maximum [Member]	'	'
Fair Value, Option, Quantitative Disclosures [Line Items]	'	'
Constant prepayment rate (Annual)	20.00%	20.00%

Structured_Stock_Repurchase_Ad

Structured Stock Repurchase - Additional Information (Detail) (USD $)	12 Months Ended			1 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011	Dec. 01, 2010	Aug. 20, 2010
				Structured Stock Repurchase Agreement [Member]	Structured Stock Repurchase Agreement [Member]
Maximum number of Company common stock shares to be repurchased under structured stock repurchase	'	'	'	'	12
Prepayment of structured stock repurchase to the counterparty	'	'	'	'	$169
Number of shares purchased from the counterparty under the structured stock repurchase	'	12	21	3.2	'
Value of shares purchased from the counterparty under the structured stock repurchase	5	208	349	50	'
Per share price of shares purchased from the counterparty under the structured stock repurchase	'	'	'	$15.94	'
Return of excess prepayment amount on structured stock repurchase	'	'	'	$119	'

Related_Party_Transactions_Add

Related Party Transactions - Additional Information (Detail) (USD $)	12 Months Ended	3 Months Ended	1 Months Ended		12 Months Ended				3 Months Ended
	Sep. 30, 2013	Dec. 31, 2012	Jan. 31, 2013	Jan. 17, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Dec. 31, 2012
		Old IDA Agreement [Member]	New IDA Agreement [Member]	New IDA Agreement [Member]	New IDA Agreement [Member]	New IDA Agreement [Member]	New IDA Agreement [Member]	New IDA Agreement [Member]	Insured Deposit Account Agreement Fee Example [Member]
						Maximum [Member]	Minimum [Member]	New Fixed Rate Notional Investments [Member]
Related Party Transaction [Line Items]	'	'	'	'	'	'	'	'	'
Toronto-Dominion Bank percentage of ownership in the Company	42.00%	'	'	'	'	'	'	'	'
Toronto-Dominion Bank's right to designate to the Company's board of directors	'Five of twelve members	'	'	'	'	'	'	'	'
Flat servicing fee (in basis points)	'	0.25%	'	'	'	'	'	'	0.25%
Component of fee earned, period for monthly average rate of LIBOR floating rate investment (in days)	'	'30 days	'	'	'	'	'	'	'
Adjustments required to adjust variable rate leg of interest rate swaps	'	'One-month reset frequency and the overall swap payment frequency to monthly	'	'	'	'	'	'	'
Amount of deposits, in the insured deposit account agreement fee example	'	'	'	'	'	'	'	'	$100,000,000
Term of deposits invested in fixed rate investments, in the insured deposit account agreement fee example	'	'	'	'	'	'	'	'	'5 years
Term of fixed rate investments that deposits are invested in, in the insured deposit account agreement fee example	'	'	'	'	'	'	'	'	'5 years
Fixed yield for applicable LIBOR-based swaps, in the insured deposit account agreement fee example	'	'	'	'	'	'	'	'	1.00%
Gross fixed yield earned on deposits, in the insured deposit account agreement fee example	'	'	'	'	'	'	'	'	1.00%
Agreement effective date	'	'	'	1-Jan-13	'	'	'	'	'
Agreement expiration date	'	'	'	1-Jul-18	'	'	'	'	'
Agreement successive renewal terms	'	'	'5 years	'	'	'	'	'	'
Prior written notice period for termination of agreement by any party	'	'	'2 years	'	'	'	'	'	'
Description of rate earned on new fixed-rate notional investments	'	'	'	'	'In the event that (1)B the federal funds effective rate is established at 0.75% or greater and (2)B the rate on 5-year U.S. dollar interest rate swaps is equal to or greater than 1.50% for 20 consecutive business days, then the rate earned by the Company on new fixed-rate notional investments will be reduced by 20% of the excess of the 5-year U.S. dollar swap rate over 1.50%, up to a maximum of 0.10%.	'	'	'	'
Event 1 Federal Funds effective rate minimum	'	'	'	'	'	'	'	0.75%	'
Event 2 Minimum Rate on five-year U.S. dollar interest rate swaps for 20 consecutive business days	'	'	'	'	'	'	'	1.50%	'
Maximum reduction to rate earned by Company in the case of event 1 and event 2	'	'	'	'	'	'	'	0.10%	'
The percentage used in the calculation to reduce the rate earned by the Company in the case of event 1 and event 2	'	'	'	'	'	'	'	20.00%	'
Term of U.S. dollar interest rate swaps	'	'	'	'	'	'	'	'5 years	'
Event 2 number of consecutive business days required above the minimum rate on U.S. dollar interest rate swaps for reduction in rate earned by Company in the case of Event 1 and Event 2	'	'	'	'	'	'	'	'20 days	'
Percentage of fixed rate notional investments	'	'	'	'	79.00%	'	'	'	'
Percentage of floating rate investments	'	'	'	'	21.00%	'	'	'	'
Servicing fee to the Depository Institutions Description	'	'	'	'	'The servicing fee to the Depository Institutions under the new IDA Agreement is equal to 25 basis points on the aggregate average daily balance in the IDA accounts, subject to adjustment as it relates to deposits of less than or equal to $20 billion kept in floating-rate investments or in fixed-rate notional investments with a maturity of up to 24 months (bshort-term fixed-rate investmentsb). For floating-rate and short-term fixed-rate investments, the servicing fee is equal to the difference of the interest rate earned on the investments less the FDIC premiums paid (in basis points), divided by two. The servicing fee has a floor of 3 basis points (subject to adjustment from time to time to reflect material changes to the Depository Institutionsb leverage costs) and a maximum of 25 basis points.	'	'	'	'
Deposit amount threshold for floating-rate or fixed-rate notional investments with a maturity of up to 24 months subject to servicing fee adjustment	'	'	'	'	'	20,000,000,000	'	'	'
Short-term fixed-rate notional investments maturity	'	'	'	'	'Up to 24 months	'	'	'	'
Servicing fee percentage (in basis points)	'	'	'	'	'	0.25%	0.03%	'	'
Contingent liability carried on the consolidated balance sheets for the Insured Deposit Account Agreement	'	'	'	'	$0	'	'	'	'

Related_Party_Transactions_Sum

Related Party Transactions - Summary of Revenues Resulting from Transactions with Related Parties (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Related Party Transaction [Line Items]	'	'	'
Revenues from TD and Affiliates	$821	$844	$782
Insured Deposit Account Fees [Member] | Insured Deposit Account Agreement [Member]	'	'	'
Related Party Transaction [Line Items]	'	'	'
Revenues from TD and Affiliates	804	828	763
Investment Product Fees [Member] | Mutual Fund Agreements [Member]	'	'	'
Related Party Transaction [Line Items]	'	'	'
Revenues from TD and Affiliates	1	3	8
Various [Member] | Referral and Strategic Alliance Agreement [Member]	'	'	'
Related Party Transaction [Line Items]	'	'	'
Revenues from TD and Affiliates	11	8	4
Various [Member] | Other [Member]	'	'	'
Related Party Transaction [Line Items]	'	'	'
Revenues from TD and Affiliates	3	2	3
Net Interest Revenue [Member] | Securities borrowing and lending, net [Member]	'	'	'
Related Party Transaction [Line Items]	'	'	'
Revenues from TD and Affiliates	$2	$3	$4

Related_Party_Transactions_Sum1

Related Party Transactions - Summary of Expenses Resulting from Transactions with Related Parties (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Related Party Transaction [Line Items]	'	'	'
Expenses to TD and Affiliates	$23	$22	$22
Professional Services [Member] | Canadian Call Center Services Agreement [Member]	'	'	'
Related Party Transaction [Line Items]	'	'	'
Expenses to TD and Affiliates	19	18	18
Various [Member] | Other [Member]	'	'	'
Related Party Transaction [Line Items]	'	'	'
Expenses to TD and Affiliates	$4	$4	$4

Related_Party_Transactions_Sum2

Related Party Transactions - Summary of Classification and Amount of Receivables from and Payables to Affiliates of Company (Detail) (USD $)	Sep. 30, 2013	Sep. 30, 2012
In Millions, unless otherwise specified
Assets:	'	'
Receivable from brokers, dealers and clearing organizations	$1,348	$1,110
Receivable from affiliates	117	85
Liabilities:	'	'
Payable to brokers, dealers and clearing organizations	1,973	1,992
Payable to affiliates	4	4
Related Party Assets [Member]	'	'
Assets:	'	'
Receivable from brokers, dealers and clearing organizations	1	1
Receivable from affiliates	117	85
Related Party Liabilities [Member]	'	'
Liabilities:	'	'
Payable to brokers, dealers and clearing organizations	115	125
Payable to affiliates	$4	$4

Condensed_Consolidating_Financ2

Condensed Consolidating Financial Information - Schedule of Condensed Consolidating Balance Sheet (Detail) (USD $)	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2010
In Millions, unless otherwise specified
ASSETS	'	'	'	'
Cash and cash equivalents	$1,062	$915	$1,032	$741
Short-term investments available-for-sale	4	154	'	'
Cash and investments segregated and on deposit for regulatory purposes	5,894	4,030	'	'
Receivable from brokers, dealers and clearing organizations	1,348	1,110	'	'
Receivable from clients, net	8,984	8,647	'	'
Investments in subsidiaries	'	'	'	'
Receivable from affiliates	117	85	'	'
Goodwill	2,467	2,467	'	'
Acquired intangible assets, net	841	932	'	'
Other, net	1,119	1,173	'	'
Total assets	21,836	19,513	'	'
Liabilities:	'	'	'	'
Payable to brokers, dealers and clearing organizations	1,973	1,992	'	'
Payable to clients	13,183	10,728	'	'
Accounts payable and accrued liabilities	582	632	'	'
Payable to affiliates	4	4	'	'
Long-term debt	1,052	1,345	'	'
Other	366	387	'	'
Total liabilities	17,160	15,088	'	'
Stockholders' equity	4,676	4,425	4,116	3,772
Total liabilities and stockholders' equity	21,836	19,513	'	'
TD Ameritrade Holding Corporation [Member]	'	'	'	'
ASSETS	'	'	'	'
Cash and cash equivalents	199	178	94	67
Short-term investments available-for-sale	'	151	'	'
Cash and investments segregated and on deposit for regulatory purposes	'	'	'	'
Receivable from brokers, dealers and clearing organizations	'	'	'	'
Receivable from clients, net	'	'	'	'
Investments in subsidiaries	5,568	5,456	'	'
Receivable from affiliates	4	5	'	'
Goodwill	'	'	'	'
Acquired intangible assets, net	'	'	'	'
Other, net	140	230	'	'
Total assets	5,911	6,020	'	'
Liabilities:	'	'	'	'
Payable to brokers, dealers and clearing organizations	'	'	'	'
Payable to clients	'	'	'	'
Accounts payable and accrued liabilities	180	249	'	'
Payable to affiliates	3	1	'	'
Long-term debt	1,052	1,345	'	'
Other	'	'	'	'
Total liabilities	1,235	1,595	'	'
Stockholders' equity	4,676	4,425	'	'
Total liabilities and stockholders' equity	5,911	6,020	'	'
Guarantor Subsidiary [Member]	'	'	'	'
ASSETS	'	'	'	'
Cash and cash equivalents	7	6	7	25
Short-term investments available-for-sale	'	'	'	'
Cash and investments segregated and on deposit for regulatory purposes	'	'	'	'
Receivable from brokers, dealers and clearing organizations	'	'	'	'
Receivable from clients, net	'	'	'	'
Investments in subsidiaries	5,360	5,250	'	'
Receivable from affiliates	3	3	'	'
Goodwill	'	'	'	'
Acquired intangible assets, net	146	146	'	'
Other, net	9	7	'	'
Total assets	5,525	5,412	'	'
Liabilities:	'	'	'	'
Payable to brokers, dealers and clearing organizations	'	'	'	'
Payable to clients	'	'	'	'
Accounts payable and accrued liabilities	'	'	'	'
Payable to affiliates	'	'	'	'
Long-term debt	'	'	'	'
Other	51	48	'	'
Total liabilities	51	48	'	'
Stockholders' equity	5,474	5,364	'	'
Total liabilities and stockholders' equity	5,525	5,412	'	'
Non-Guarantor Subsidiaries [Member]	'	'	'	'
ASSETS	'	'	'	'
Cash and cash equivalents	856	731	931	649
Short-term investments available-for-sale	4	3	'	'
Cash and investments segregated and on deposit for regulatory purposes	5,894	4,030	'	'
Receivable from brokers, dealers and clearing organizations	1,348	1,110	'	'
Receivable from clients, net	8,984	8,647	'	'
Investments in subsidiaries	550	548	'	'
Receivable from affiliates	117	83	'	'
Goodwill	2,467	2,467	'	'
Acquired intangible assets, net	695	786	'	'
Other, net	1,011	961	'	'
Total assets	21,926	19,366	'	'
Liabilities:	'	'	'	'
Payable to brokers, dealers and clearing organizations	1,973	1,992	'	'
Payable to clients	13,183	10,728	'	'
Accounts payable and accrued liabilities	410	391	'	'
Payable to affiliates	8	9	'	'
Long-term debt	'	'	'	'
Other	348	356	'	'
Total liabilities	15,922	13,476	'	'
Stockholders' equity	6,004	5,890	'	'
Total liabilities and stockholders' equity	21,926	19,366	'	'
Eliminations [Member]	'	'	'	'
ASSETS	'	'	'	'
Cash and cash equivalents	'	'	'	'
Short-term investments available-for-sale	'	'	'	'
Cash and investments segregated and on deposit for regulatory purposes	'	'	'	'
Receivable from brokers, dealers and clearing organizations	'	'	'	'
Receivable from clients, net	'	'	'	'
Investments in subsidiaries	-11,478	-11,254	'	'
Receivable from affiliates	-7	-6	'	'
Goodwill	'	'	'	'
Acquired intangible assets, net	'	'	'	'
Other, net	-41	-25	'	'
Total assets	-11,526	-11,285	'	'
Liabilities:	'	'	'	'
Payable to brokers, dealers and clearing organizations	'	'	'	'
Payable to clients	'	'	'	'
Accounts payable and accrued liabilities	-8	-8	'	'
Payable to affiliates	-7	-6	'	'
Long-term debt	'	'	'	'
Other	-33	-17	'	'
Total liabilities	-48	-31	'	'
Stockholders' equity	-11,478	-11,254	'	'
Total liabilities and stockholders' equity	($11,526)	($11,285)	'	'

Condensed_Consolidating_Financ3

Condensed Consolidating Financial Information - Schedule of Condensed Consolidating Statement of Income (Detail) (USD $)	3 Months Ended								12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Condensed Income Statements, Captions [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net revenues	$709	$725	$679	$651	$647	$667	$673	$653	$2,764	$2,641	$2,763
Operating expenses	'	'	'	'	'	'	'	'	1,708	1,707	1,715
Operating income	279	298	237	241	232	254	219	228	1,056	934	1,048
Other expense (income)	'	'	'	'	'	'	'	'	-32	28	31
Income (loss) before income taxes and equity in income of subsidiaries	'	'	'	'	'	'	'	'	1,088	906	1,017
Provision for (benefit from) income taxes	'	'	'	'	'	'	'	'	413	320	379
Income (loss) before equity in income of subsidiaries	'	'	'	'	'	'	'	'	675	586	638
Equity in income of subsidiaries	'	'	'	'	'	'	'	'	'	'	'
Net income	200	184	144	147	143	154	137	152	675	586	638
TD Ameritrade Holding Corporation [Member]	'	'	'	'	'	'	'	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net revenues	'	'	'	'	'	'	'	'	12	32	17
Operating expenses	'	'	'	'	'	'	'	'	10	28	16
Operating income	'	'	'	'	'	'	'	'	2	4	1
Other expense (income)	'	'	'	'	'	'	'	'	-23	29	33
Income (loss) before income taxes and equity in income of subsidiaries	'	'	'	'	'	'	'	'	25	-25	-32
Provision for (benefit from) income taxes	'	'	'	'	'	'	'	'	8	-19	-13
Income (loss) before equity in income of subsidiaries	'	'	'	'	'	'	'	'	17	-6	-19
Equity in income of subsidiaries	'	'	'	'	'	'	'	'	658	592	657
Net income	'	'	'	'	'	'	'	'	675	586	638
Guarantor Subsidiary [Member]	'	'	'	'	'	'	'	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net revenues	'	'	'	'	'	'	'	'	'	'	'
Operating expenses	'	'	'	'	'	'	'	'	'	'	'
Operating income	'	'	'	'	'	'	'	'	'	'	'
Other expense (income)	'	'	'	'	'	'	'	'	'	'	'
Income (loss) before income taxes and equity in income of subsidiaries	'	'	'	'	'	'	'	'	'	'	'
Provision for (benefit from) income taxes	'	'	'	'	'	'	'	'	'	-3	-1
Income (loss) before equity in income of subsidiaries	'	'	'	'	'	'	'	'	'	3	1
Equity in income of subsidiaries	'	'	'	'	'	'	'	'	634	577	673
Net income	'	'	'	'	'	'	'	'	634	580	674
Non-Guarantor Subsidiaries [Member]	'	'	'	'	'	'	'	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net revenues	'	'	'	'	'	'	'	'	2,763	2,641	2,763
Operating expenses	'	'	'	'	'	'	'	'	1,709	1,711	1,716
Operating income	'	'	'	'	'	'	'	'	1,054	930	1,047
Other expense (income)	'	'	'	'	'	'	'	'	-9	-1	-2
Income (loss) before income taxes and equity in income of subsidiaries	'	'	'	'	'	'	'	'	1,063	931	1,049
Provision for (benefit from) income taxes	'	'	'	'	'	'	'	'	405	342	393
Income (loss) before equity in income of subsidiaries	'	'	'	'	'	'	'	'	658	589	656
Equity in income of subsidiaries	'	'	'	'	'	'	'	'	36	33	38
Net income	'	'	'	'	'	'	'	'	694	622	694
Eliminations [Member]	'	'	'	'	'	'	'	'	'	'	'
Condensed Income Statements, Captions [Line Items]	'	'	'	'	'	'	'	'	'	'	'
Net revenues	'	'	'	'	'	'	'	'	-11	-32	-17
Operating expenses	'	'	'	'	'	'	'	'	-11	-32	-17
Operating income	'	'	'	'	'	'	'	'	'	'	'
Other expense (income)	'	'	'	'	'	'	'	'	'	'	'
Income (loss) before income taxes and equity in income of subsidiaries	'	'	'	'	'	'	'	'	'	'	'
Provision for (benefit from) income taxes	'	'	'	'	'	'	'	'	'	'	'
Income (loss) before equity in income of subsidiaries	'	'	'	'	'	'	'	'	'	'	'
Equity in income of subsidiaries	'	'	'	'	'	'	'	'	-1,328	-1,202	-1,368
Net income	'	'	'	'	'	'	'	'	($1,328)	($1,202)	($1,368)

Condensed_Consolidating_Financ4

Condensed Consolidating Financial Information - Schedule of Condensed Consolidating Statement of Cash Flows (Detail) (USD $)	12 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Condensed Cash Flow Statements, Captions [Line Items]	'	'	'
Net cash provided by (used in) operating activities	$739	$592	$790
Cash flows from investing activities:	'	'	'
Purchase of property and equipment	-144	-186	-153
Proceeds from sale and maturity of short-term investments	154	4	4
Purchase of short-term investments	-4	-155	-4
Purchase of investments	'	-44	-5
Proceeds from sale of investments	88	2	3
Other, net	2	2	3
Net cash provided by (used in) investing activities	96	-377	-152
Cash flows from financing activities:	'	'	'
Principal payments on long-term debt	-250	'	-4
Proceeds from notes payable	275	'	'
Principal payments on notes payable	-275	'	'
Payment of cash dividends	-471	-132	-114
Purchase of treasury stock	-5	-208	-349
Return of prepayment on structured stock repurchase	'	'	119
Other, net	38	8	1
Net cash provided by (used in) financing activities	-688	-332	-347
Intercompany investing and financing activities, net	'	'	'
Net increase (decrease) in cash and cash equivalents	147	-117	291
Cash and cash equivalents at beginning of year	915	1,032	741
Cash and cash equivalents at end of year	1,062	915	1,032
TD Ameritrade Holding Corporation [Member]	'	'	'
Condensed Cash Flow Statements, Captions [Line Items]	'	'	'
Net cash provided by (used in) operating activities	-70	46	-45
Cash flows from investing activities:	'	'	'
Purchase of property and equipment	'	'	'
Proceeds from sale and maturity of short-term investments	150	'	'
Purchase of short-term investments	'	-152	'
Purchase of investments	'	-43	'
Proceeds from sale of investments	78	2	'
Other, net	'	'	'
Net cash provided by (used in) investing activities	228	-193	'
Cash flows from financing activities:	'	'	'
Principal payments on long-term debt	-250	'	'
Proceeds from notes payable	275	'	'
Principal payments on notes payable	-275	'	'
Payment of cash dividends	-471	-132	-114
Purchase of treasury stock	-5	-208	-349
Return of prepayment on structured stock repurchase	'	'	119
Other, net	43	4	13
Net cash provided by (used in) financing activities	-683	-336	-331
Intercompany investing and financing activities, net	546	567	403
Net increase (decrease) in cash and cash equivalents	21	84	27
Cash and cash equivalents at beginning of year	178	94	67
Cash and cash equivalents at end of year	199	178	94
Guarantor Subsidiary [Member]	'	'	'
Condensed Cash Flow Statements, Captions [Line Items]	'	'	'
Net cash provided by (used in) operating activities	1	2	202
Cash flows from investing activities:	'	'	'
Purchase of property and equipment	'	'	'
Proceeds from sale and maturity of short-term investments	'	'	'
Purchase of short-term investments	'	'	'
Proceeds from sale of investments	'	'	'
Other, net	'	'	'
Net cash provided by (used in) investing activities	'	'	'
Cash flows from financing activities:	'	'	'
Principal payments on long-term debt	'	'	'
Proceeds from notes payable	'	'	'
Principal payments on notes payable	'	'	'
Payment of cash dividends	'	'	'
Purchase of treasury stock	'	'	'
Other, net	'	'	'
Net cash provided by (used in) financing activities	'	'	'
Intercompany investing and financing activities, net	'	-3	-220
Net increase (decrease) in cash and cash equivalents	1	-1	-18
Cash and cash equivalents at beginning of year	6	7	25
Cash and cash equivalents at end of year	7	6	7
Non-Guarantor Subsidiaries [Member]	'	'	'
Condensed Cash Flow Statements, Captions [Line Items]	'	'	'
Net cash provided by (used in) operating activities	808	544	633
Cash flows from investing activities:	'	'	'
Purchase of property and equipment	-144	-186	-153
Proceeds from sale and maturity of short-term investments	4	4	4
Purchase of short-term investments	-4	-3	-4
Purchase of investments	'	-1	-5
Proceeds from sale of investments	10	'	3
Other, net	2	2	3
Net cash provided by (used in) investing activities	-132	-184	-152
Cash flows from financing activities:	'	'	'
Principal payments on long-term debt	'	'	-4
Proceeds from notes payable	'	'	'
Principal payments on notes payable	'	'	'
Payment of cash dividends	'	'	'
Purchase of treasury stock	'	'	'
Other, net	-5	4	-12
Net cash provided by (used in) financing activities	-5	4	-16
Intercompany investing and financing activities, net	-546	-564	-183
Net increase (decrease) in cash and cash equivalents	125	-200	282
Cash and cash equivalents at beginning of year	731	931	649
Cash and cash equivalents at end of year	$856	$731	$931

Quarterly_Data_Schedule_of_Qua

Quarterly Data - Schedule of Quarterly Financial Data (Detail) (USD $)	3 Months Ended								12 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2011
Quarterly Financial Information Disclosure [Abstract]	'	'	'	'	'	'	'	'	'	'	'
Net revenues	$709	$725	$679	$651	$647	$667	$673	$653	$2,764	$2,641	$2,763
Operating income	279	298	237	241	232	254	219	228	1,056	934	1,048
Net income	$200	$184	$144	$147	$143	$154	$137	$152	$675	$586	$638
Basic earnings per share	$0.36	$0.33	$0.26	$0.27	$0.26	$0.28	$0.25	$0.28	$1.23	$1.07	$1.12
Diluted earnings per share	$0.36	$0.33	$0.26	$0.27	$0.26	$0.28	$0.25	$0.27	$1.22	$1.06	$1.11

Quarterly_Data_Schedule_of_Qua1

Quarterly Data - Schedule of Quarterly Financial Data (Parenthetical) (Detail) (Knight-GETCO Merger Impact [Member], USD $)	3 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013
Knight-GETCO Merger Impact [Member]	'
Interim Reporting [Line Items]	'
Pre-tax gain in connection with Knight-GETCO merger	$54
After tax gain in connection with Knight-GETCO merger	$34
Per diluted share impact of the after tax gain in connection with Knight-GETCO merger	$0.06