v3.25.2
Reporting Segments (Information by Reporting Segment) (Detail) - USD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2025
Mar. 31, 2025
Jun. 30, 2024
Mar. 31, 2024
Jun. 30, 2025
Jun. 30, 2024
Noninterest Income            
Trust, Investment and Other Servicing Fees $ 1,231.1   $ 1,166.1   $ 2,444.9 $ 2,309.0
Foreign Exchange Trading Income 50.6   58.4   109.3 115.4
Other Noninterest Income (Loss) 105.7   968.1   205.1 886.9
Total Noninterest Income 1,387.4   2,192.6   2,759.3 3,311.3
Net interest income 610.5   522.9   1,178.6 1,051.0
Revenue 1,997.9   2,715.5   3,937.9 4,362.3
Provision for Credit Losses 16.5   8.0   17.5 (0.5)
Compensation 614.8   665.2   1,259.2 1,292.3
Employee Benefits 117.7   100.2   227.4 201.3
Outside Services 247.0   260.9   492.2 490.2
Allocated Expense 0.0   0.0   0.0 0.0
Other Segment Items 437.1   507.6   855.4 914.8
Total Noninterest Expense 1,416.6   1,533.9   2,834.2 2,898.6
Income before Income Taxes 564.8   1,173.6   1,086.2 1,464.2
Provision for Income Taxes 143.5   277.5   272.9 353.4
Net Income $ 421.3 $ 392.0 $ 896.1 $ 214.7 $ 813.3 $ 1,110.8
Percentage of Consolidated Net Income 100.00%   100.00%   100.00% 100.00%
Average Assets $ 157,719.2   $ 148,001.2   $ 154,011.3 $ 146,559.8
Average Loans 41,158.0   41,034.6   41,117.4 41,310.7
Average Deposits 122,377.8   113,341.6   119,166.3 112,852.2
Other            
Noninterest Income            
Trust, Investment and Other Servicing Fees 0.0   0.0   0.0 0.0
Foreign Exchange Trading Income 0.0   0.0   0.0 0.0
Other Noninterest Income (Loss) 0.5   878.7   (2.2) 688.3
Total Noninterest Income 0.5   878.7   (2.2) 688.3
Net interest income (5.0)   (4.1)   (10.7) (10.0)
Revenue (4.5)   874.6   (12.9) 678.3
Provision for Credit Losses 1.4   (1.5)   1.2 (2.5)
Compensation 397.4   377.6   796.4 764.3
Employee Benefits 78.4   62.4   148.6 125.9
Outside Services 186.1   195.9   370.1 365.8
Allocated Expense (1,045.7)   (997.0)   (2,062.2) (1,958.9)
Other Segment Items 393.8   461.9   767.2 829.6
Total Noninterest Expense 10.0   100.8   20.1 126.7
Income before Income Taxes (15.9)   775.3   (34.2) 554.1
Provision for Income Taxes 9.8   182.0   13.9 135.8
Net Income $ (25.7)   $ 593.3   $ (48.1) $ 418.3
Percentage of Consolidated Net Income (7.00%)   66.00%   (6.00%) 38.00%
Average Assets $ 1,580.1   $ 882.2   $ 1,457.2 $ 494.1
Average Loans 0.0   0.0   0.0 0.0
Average Deposits 1,580.1   882.2   1,457.2 494.1
ASSET SERVICING | Operating Segments            
Noninterest Income            
Trust, Investment and Other Servicing Fees 691.8   650.6   1,363.7 1,290.2
Foreign Exchange Trading Income 61.0   62.2   124.9 122.1
Other Noninterest Income (Loss) 70.6   59.4   139.2 130.1
Total Noninterest Income 823.4   772.2   1,627.8 1,542.4
Net interest income 347.2   282.7   670.9 575.3
Revenue 1,170.6   1,054.9   2,298.7 2,117.7
Provision for Credit Losses 3.9   4.5   6.0 (1.3)
Compensation 75.2   132.4   169.5 228.1
Employee Benefits 16.4   17.2   33.8 34.3
Outside Services 43.9   52.4   90.8 101.9
Allocated Expense 740.7   689.2   1,450.3 1,355.0
Other Segment Items 19.4   23.6   41.8 44.8
Total Noninterest Expense 895.6   914.8   1,786.2 1,764.1
Income before Income Taxes 271.1   135.6   506.5 354.9
Provision for Income Taxes 58.1   29.2   108.9 77.7
Net Income $ 213.0   $ 106.4   $ 397.6 $ 277.2
Percentage of Consolidated Net Income 51.00%   12.00%   49.00% 25.00%
Average Assets $ 117,044.6   $ 108,290.3   $ 113,432.9 $ 107,563.3
Average Loans 5,812.8   6,472.3   5,781.2 6,690.9
Average Deposits 95,506.7   86,223.0   92,418.8 86,455.9
WEALTH MANAGEMENT | Operating Segments            
Noninterest Income            
Trust, Investment and Other Servicing Fees 539.3   515.5   1,081.2 1,018.8
Foreign Exchange Trading Income (10.4)   (3.8)   (15.6) (6.7)
Other Noninterest Income (Loss) 34.6   30.0   68.1 68.5
Total Noninterest Income 563.5   541.7   1,133.7 1,080.6
Net interest income 268.3   244.3   518.4 485.7
Revenue 831.8   786.0   1,652.1 1,566.3
Provision for Credit Losses 11.2   5.0   10.3 3.3
Compensation 142.2   155.2   293.3 299.9
Employee Benefits 22.9   20.6   45.0 41.1
Outside Services 17.0   12.6   31.3 22.5
Allocated Expense 305.0   307.8   611.9 603.9
Other Segment Items 23.9   22.1   46.4 40.4
Total Noninterest Expense 511.0   518.3   1,027.9 1,007.8
Income before Income Taxes 309.6   262.7   613.9 555.2
Provision for Income Taxes 75.6   66.3   150.1 139.9
Net Income $ 234.0   $ 196.4   $ 463.8 $ 415.3
Percentage of Consolidated Net Income 56.00%   22.00%   57.00% 37.00%
Average Assets $ 39,094.5   $ 38,828.7   $ 39,121.2 $ 38,502.4
Average Loans 35,345.2   34,562.3   35,336.2 34,619.8
Average Deposits $ 25,291.0   $ 26,236.4   $ 25,290.3 $ 25,902.2