Consolidated Comprehensive Income Statements - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 11,179	$ 9,237	$ 8,883
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	170	3	(90)
Change in net unrealized gains (losses) on available-for-sale securities	1,580	1,137	(272)
Pension and other	146	(66)	137
Change in net debt valuation adjustment	(1,028)	(1,639)	1,517
Total other comprehensive income (loss)	868	(565)	1,292
Comprehensive income	12,047	8,672	10,175
Net income applicable to noncontrolling interests	183	195	135
Other comprehensive income (loss) applicable to noncontrolling interests	42	(69)	87
Comprehensive income applicable to Morgan Stanley	$ 11,822	$ 8,546	$ 9,953