Consolidated Comprehensive Income Statements - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net income	$ 2,246	$ 2,467	$ 4,714	$ 5,171
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments	65	(192)	43	(75)
Change in net unrealized gains (losses) on available-for-sale securities	609	(126)	1,038	(536)
Pension, postretirement and other	3	6	4	11
Change in net debt valuation adjustment	(246)	639	(866)	1,090
Total other comprehensive income (loss)	431	327	219	490
Comprehensive income	2,677	2,794	4,933	5,661
Net income applicable to noncontrolling interests	45	30	84	66
Other comprehensive income (loss) applicable to noncontrolling interests	9	(9)	(22)	63
Comprehensive income applicable to Morgan Stanley	$ 2,623	$ 2,773	$ 4,871	$ 5,532