Regulatory Capital (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Retained earnings	$ 27,028	$ 25,238
Capital ratio: required common equity tier 1 capital	8.00%	8.00%
Capital ratio: required tier 1 capital	0.095	0.095
Capital ratio: required total capital	0.115	0.115
Tier 1 leverage capital ratio, minimum	0.040	0.040
Capital conservation buffer, capital conserved, minimum	0.025
Stress capital buffer, minimum	2.50%
Banking Regulation, Global Systemically Important Bank (GSIB) Surcharge	0.010
Countercyclical capital buffer	0
Leverage ratio minimum	0.05
Basel III Advanced Approaches
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common stock and related surplus	$ 11,234	$ 11,291
Retained earnings	27,028	25,238
Accumulated other comprehensive income (loss)	(3,711)	(1,133)
Treasury stock, at cost		(10,009)
Total	23,215	25,387
Goodwill and other intangible assets, net of associated deferred tax liabilities	(8,545)	(8,935)
Other adjustments(1)	(123)	(505)
Common equity tier 1 capital	14,547	15,947
Preferred stock	1,976	1,976
Tier 1 capital	16,523	17,923
Qualifying subordinated long-term debt	1,376	1,588
Allowance for credit losses	0	0
Total capital	17,899	19,511
Credit risk	61,108	63,735
Operational risk	42,763	45,550
Market risk	1,488	2,113
Total risk-weighted assets	105,359	111,398
Adjusted quarterly average assets	$ 275,678	$ 293,567
Common equity tier 1 capital	13.80%	14.30%
Tier 1 capital	0.157	0.161
Total capital	0.170	0.175
Tier 1 leverage capital ratio, actual	0.060	0.061
Basel III Standardized Approach
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common stock and related surplus	$ 11,234	$ 11,291
Retained earnings	27,028	25,238
Accumulated other comprehensive income (loss)	(3,711)	(1,133)
Total	23,215	25,387
Goodwill and other intangible assets, net of associated deferred tax liabilities	(8,545)	(8,935)
Other adjustments(1)	(123)	(505)
Common equity tier 1 capital	14,547	15,947
Preferred stock	1,976	1,976
Tier 1 capital	16,523	17,923
Qualifying subordinated long-term debt	1,376	1,588
Allowance for credit losses	120	108
Total capital	18,019	19,619
Credit risk	105,739	109,554
Market risk	1,488	2,113
Total risk-weighted assets	107,227	111,667
Adjusted quarterly average assets	$ 275,678	$ 293,567
Common equity tier 1 capital	13.60%	14.30%
Tier 1 capital	0.154	0.161
Total capital	0.168	0.176
Tier 1 leverage capital ratio, actual	0.060	0.061
State Street Bank | Basel III Advanced Approaches
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common stock and related surplus	$ 13,033	$ 13,047
Retained earnings	16,975	15,700
Accumulated other comprehensive income (loss)	(3,428)	(926)
Treasury stock, at cost	0	0
Total	26,580	27,821
Goodwill and other intangible assets, net of associated deferred tax liabilities	(8,288)	(8,667)
Other adjustments(1)	(19)	(309)
Common equity tier 1 capital	18,273	18,845
Preferred stock	0	0
Tier 1 capital	18,273	18,845
Qualifying subordinated long-term debt	542	752
Allowance for credit losses	0	0
Total capital	18,815	19,597
Credit risk	54,675	57,405
Operational risk	42,325	42,813
Market risk	1,488	2,113
Total risk-weighted assets	98,488	102,331
Adjusted quarterly average assets	$ 273,220	$ 290,403
Common equity tier 1 capital	18.60%	18.40%
Tier 1 capital	0.186	0.184
Total capital	0.191	0.192
Tier 1 leverage capital ratio, actual	0.067	0.065
State Street Bank | Basel III Standardized Approach
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common stock and related surplus	$ 13,033	$ 13,047
Retained earnings	16,975	15,700
Accumulated other comprehensive income (loss)	(3,428)	(926)
Treasury stock, at cost	0	0
Total	26,580	27,821
Goodwill and other intangible assets, net of associated deferred tax liabilities	(8,288)	(8,667)
Other adjustments(1)	(19)	(309)
Common equity tier 1 capital	18,273	18,845
Preferred stock	0	0
Tier 1 capital	18,273	18,845
Qualifying subordinated long-term debt	542	752
Allowance for credit losses	120	108
Total capital	18,935	19,705
Credit risk	104,184	106,405
Market risk	1,488	2,113
Total risk-weighted assets	105,672	108,518
Adjusted quarterly average assets	$ 273,220	$ 290,403
Common equity tier 1 capital	17.30%	17.40%
Tier 1 capital	0.173	0.174
Total capital	0.179	0.182
Tier 1 leverage capital ratio, actual	0.067	0.065