Parent Company - Condensed Income Statements and Comprehensive Income Statements (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Revenues
Trading	$ 12,810	$ 13,983	$ 11,274
Other	3,694	3,132	2,327
Total non-interest revenues	51,710	42,444	36,844
Interest income	9,411	10,162	17,098
Interest expense	1,366	3,849	12,404
Net interest	8,045	6,313	4,694
Net revenues	59,755	48,757	41,538
Total non-interest expenses	40,083	33,578	30,076
Provision for (benefit from) income taxes	4,548	3,239	2,064
Undistributed gain of subsidiaries			3,254
Net income	15,120	11,179	9,237
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(331)	170	3
Change in net unrealized gains (losses) on available-for-sale securities	(1,542)	1,580	1,137
Change in net debt valuation adjustment	696	(1,028)	(1,639)
Comprehensive income	13,890	12,047	8,672
Net income	15,120	11,179	9,237
Preferred stock dividends and other	468	496	530
Earnings applicable to Morgan Stanley common shareholders	14,566	10,500	8,512
Parent Company
Revenues
Dividends from bank subsidiaries	0	2,811	3,531
Dividends from BHC and non-bank subsidiaries	8,898	1,170	1,998
Total dividends from subsidiaries	8,898	3,981	5,529
Trading	229	(244)	(54)
Other	4	51	80
Total non-interest revenues	9,131	3,788	5,555
Interest income	2,648	3,666	5,121
Interest expense	2,822	3,087	4,661
Net interest	(174)	579	460
Net revenues	8,957	4,367	6,015
Total non-interest expenses	443	387	300
Income before income taxes	8,514	3,980	5,715
Provision for (benefit from) income taxes	(203)	(109)	(73)
Net income before undistributed gain of subsidiaries	8,717	4,089	5,788
Undistributed gain of subsidiaries	6,317	6,907
Net income	15,034	10,996	9,042
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	(207)	102	(8)
Change in net unrealized gains (losses) on available-for-sale securities	(1,542)	1,580	1,137
Pensions and other	(53)	146	(66)
Change in net debt valuation adjustment	662	(1,002)	(1,559)
Comprehensive income	13,894	11,822	8,546
Net income	15,034	10,996	9,042
Preferred stock dividends and other	468	496	530
Earnings applicable to Morgan Stanley common shareholders	$ 14,566	$ 10,500	$ 8,512