CONSOLIDATED STATEMENT OF CASH FLOWS - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash flows from operating activities of continuing operations
Net income before attribution of noncontrolling interests		$ 19,467	$ 18,080	$ (6,738)
Net income attributable to noncontrolling interests		66	35	60
Citigroup’s net income (loss)		19,401	18,045	(6,798)
Loss from discontinued operations, net of taxes		(4)	(8)	(111)
Income (loss) from continuing operations—excluding noncontrolling interests		19,405	18,053	(6,687)
Adjustments to reconcile net income to net cash provided by (used in) operating activities of continuing operations
Net gains on significant disposals	[1]	0	(247)	(602)
Depreciation and amortization		3,905	3,754	3,659
Deferred income taxes	[2]	(610)	(51)	24,877
Provision for loan losses		8,218	7,354	7,503
Realized gains from sales of investments		(1,474)	(421)	(778)
Net impairment losses on investments		32	132	91
Change in trading account assets		(20,124)	(3,469)	(7,038)
Change in trading account liabilities		(24,411)	19,135	(15,375)
Change in brokerage receivables net of brokerage payables		(20,377)	6,163	(5,307)
Change in loans HFS		(909)	770	247
Change in other assets		4,724	(5,791)	(3,364)
Change in other liabilities		1,829	(871)	(3,044)
Other, net		16,955	(7,559)	(2,956)
Total adjustments		(32,242)	18,899	(2,087)
Net cash provided by (used in) operating activities of continuing operations		(12,837)	36,952	(8,774)
Cash flows from investing activities of continuing operations
Change in securities borrowed and purchased under agreements to resell		19,362	(38,206)	4,335
Change in loans		(22,466)	(29,002)	(58,062)
Proceeds from sales and securitizations of loans		2,878	4,549	8,365
Purchases of investments		(274,491)	(152,487)	(185,740)
Proceeds from sales of investments		137,173	61,491	107,368
Proceeds from maturities of investments		119,051	83,604	84,369
Proceeds from significant disposals	[1]	0	314	3,411
Capital expenditures on premises and equipment and capitalized software		(5,336)	(3,774)	(3,361)
Proceeds from sales of premises and equipment, subsidiaries and affiliates and repossessed assets		259	212	377
Other, net		196	181	187
Net cash used in investing activities of continuing operations		(23,374)	(73,118)	(38,751)
Cash flows from financing activities of continuing operations
Dividends paid		(5,447)	(5,020)	(3,797)
Issuance of preferred stock		1,496	0	0
Redemption of preferred stock		(1,980)	(793)	0
Treasury stock acquired		(17,571)	(14,433)	(14,541)
Stock tendered for payment of withholding taxes		(364)	(482)	(405)
Change in securities loaned and sold under agreements to repurchase		(11,429)	21,491	14,456
Issuance of long-term debt		59,134	60,655	67,960
Payments and redemptions of long-term debt		(51,029)	(58,132)	(40,986)
Change in deposits		57,420	53,348	30,416
Change in short-term borrowings			(12,106)
Change in short-term borrowings		12,703		13,751
Net cash provided by financing activities of continuing operations		42,933	44,528	66,854
Effect of exchange rate changes on cash and cash equivalents		(908)	(773)	693
Change in cash and due from banks and deposits with banks		5,814	7,589	20,022
Cash, due from banks and deposits with banks at beginning of period	[3]	188,105	180,516	160,494
Cash, due from banks and deposits with banks at end of period	[3]	193,919	188,105	180,516
Cash, due from banks and deposits with banks at end of period	[3]	193,919	180,516	160,494
Supplemental disclosure of cash flow information for continuing operations
Cash paid during the year for income taxes		4,888	4,313	2,083
Cash paid during the year for interest		28,682	22,963	15,675
Non-cash investing activities
Transfers to loans HFS (Other assets) from loans	[4]	$ 5,500	$ 4,200	$ 5,900

[1] See Note 2 to the Consolidated Financial Statements for further information on significant disposals.

[2] Includes the full impact of the $22.6 billion non-cash charge related to the Tax Cuts and Jobs Act (Tax Reform) in 2017. See Notes 1 and 9 to the Consolidated Financial Statements for further information.

[3] Includes the impact of ASU 2016-18, Restricted Cash. See Notes 1 and 26 to the Consolidated Financial Statements.

[4] Operating and finance lease right-of-use assets and lease liabilities represent non-cash investing and financing activities, respectively, and are not included in the non-cash investing activities presented here. See Note 26 to the Consolidated Financial Statements for more information and balances as of December 31, 2019.