Line of Business Information - Summary of Line of Business (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
Segment Reporting Information [Line Items]
Servicing fees	$ 1,381	$ 1,339	$ 2,802	$ 2,635
Management fees	465	397	937	779
Trading services	315	289	619	564
Securities finance	154	179	295	312
Processing fees and other	43	31	83	143
Total fee revenue	2,358	2,235	4,736	4,433
Net interest income	659	575	1,302	1,085
Gains (losses) related to investment securities, net	9	0	7	(40)
Total revenue	3,026	2,810	6,045	5,478
Provision for loan losses	2	3	2	1
Total expenses	2,159	2,031	4,415	4,117
Income before income tax expense (benefit)	$ 865	$ 776	$ 1,628	$ 1,360
Pre-tax margin	29.00%	28.00%	27.00%	25.00%
Investment Servicing
Segment Reporting Information [Line Items]
Total revenue	$ 2,530		$ 5,052
Investment Management
Segment Reporting Information [Line Items]
Total revenue	496		993
Operating Segments \| Investment Servicing
Segment Reporting Information [Line Items]
Servicing fees	1,381	$ 1,339	2,802	$ 2,635
Management fees	0	0	0	0
Trading services	282	272	555	529
Securities finance	154	179	295	312
Processing fees and other	41	32	82	138
Total fee revenue	1,858	1,822	3,734	3,614
Net interest income	663	576	1,311	1,085
Gains (losses) related to investment securities, net	9	0	7	(40)
Total revenue	2,530	2,398	5,052	4,659
Provision for loan losses	2	3	2	1
Total expenses	1,693	1,649	3,551	3,377
Income before income tax expense (benefit)	$ 835	$ 746	$ 1,499	$ 1,281
Pre-tax margin	33.00%	31.00%	30.00%	27.00%
Operating Segments \| Investment Management
Segment Reporting Information [Line Items]
Servicing fees	$ 0	$ 0	$ 0	$ 0
Management fees	465	397	937	779
Trading services	33	17	64	35
Securities finance	0	0	0	0
Processing fees and other	2	(1)	1	5
Total fee revenue	500	413	1,002	819
Net interest income	(4)	(1)	(9)	0
Gains (losses) related to investment securities, net	0	0	0	0
Total revenue	496	412	993	819
Provision for loan losses	0	0	0	0
Total expenses	389	311	787	640
Income before income tax expense (benefit)	$ 107	$ 101	$ 206	$ 179
Pre-tax margin	22.00%	25.00%	21.00%	22.00%
Other
Segment Reporting Information [Line Items]
Servicing fees	$ 0	$ 0	$ 0	$ 0
Management fees	0	0	0	0
Trading services	0	0	0	0
Securities finance	0	0	0	0
Processing fees and other	0	0	0	0
Total fee revenue	0	0	0	0
Net interest income	0	0	0	0
Gains (losses) related to investment securities, net	0	0	0	0
Total revenue	0	0	0	0
Provision for loan losses	0	0	0	0
Total expenses	77	71	77	100
Income before income tax expense (benefit)	$ (77)	$ (71)	$ (77)	$ (100)

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Trading Services Revenue

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Income from services rendered by trust departments or by any consolidated subsidiaries acting in a fiduciary capacity, including fees earned for (1) acting as an agent for fiduciary placement and loans and (2) custody or investment advisory services when such fees are not separately billed to the customer. This item excludes commissions and fees received for the accumulation or disbursement of funds deposited to Individual Retirement or Keogh plan accounts when such are not handled by the reporting entity's trust department.

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Amount of fee and commission revenue classified as other.

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Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

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The net amount of operating interest income (expense).

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Amount of revenue from providing investment advisory, asset management and administrative services, including, but not limited to, distribution and shareholder services, accounting, tax, legal, regulatory filing, share registration, and shareholder correspondence activities.

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Amount of fees and commissions from banking, advisory, brokerage, and securities underwriting activities. Activities include, but are not limited to, underwriting securities, private placements of securities, investment advisory and management services, merger and acquisition services, sale and servicing of mutual funds, and other related consulting fees.

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This item represents the net total realized and unrealized gain (loss) included in earnings for the period as a result of selling or holding marketable securities categorized as trading, available-for-sale, or held-to-maturity, including the unrealized holding gain (loss) of held-to-maturity securities transferred to the trading security category and the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) for available-for-sale securities transferred to trading securities during the period. Additionally, this item would include any losses recognized for other than temporary impairments (OTTI) of the subject investments in debt and equity securities.

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Total aggregate amount of all noninterest expense.

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The total amount of noninterest income which may be derived from: (1) fees and commissions; (2) premiums earned; (3) insurance policy charges; (4) the sale or disposal of assets; and (5) other sources not otherwise specified.

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Amount of expense related to estimated loss from loan and lease transactions.

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-Topic 942
-SubTopic 225
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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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