REGULATORY CAPITAL (Tables)

12 Months Ended

Dec. 31, 2018

Banking and Thrift [Abstract]

Schedule of compliance with regulatory capital requirements under banking regulations

 The following table sets forth for Citigroup and Citibank the regulatory capital tiers, total risk-weighted assets, quarterly adjusted average total assets, Total Leverage Exposure, risk-based capital ratios and leverage ratios:

In millions of dollars, except ratios	Stated minimum		Citigroup					Citibank
			Well- capitalized minimum		December 31, 2018			Well- capitalized minimum		December 31, 2018
Common Equity Tier 1 Capital					$	139,252				$	129,217
Tier 1 Capital					158,122					131,341
Total Capital(Tier 1 Capital + Tier 2 Capital)—Standardized Approach					195,440					155,280
Total Capital(Tier 1 Capital + Tier 2 Capital)—Advanced Approaches					183,144					144,485
Total risk-weighted assets—Standardized Approach					1,174,448					1,030,514
Total risk-weighted assets—Advanced Approaches					1,131,933					927,931
Quarterly adjusted average total assets(1)					1,896,959					1,399,029
Total Leverage Exposure(2)					2,465,641					1,914,817
Common Equity Tier 1 Capital ratio(3)	4.5	%	N/A		11.86		%	6.5	%	12.54		%
Tier 1 Capital ratio(3)	6.0		6.0	%	13.46			8.0		12.75
Total Capital ratio(3)	8.0		10.0		16.18			10.0		15.07
Tier 1 Leverage ratio	4.0		N/A		8.34			5.0		9.39
Supplementary Leverage ratio	3.0		N/A		6.41			6.0		6.86

(1) Tier 1 Leverage ratio denominator.

(2) Supplementary Leverage ratio denominator.

(3) As of December 31, 2018, Citigroup’s reportable Common Equity Tier 1 Capital and Tier 1 Capital ratios were the lower derived under the Basel III Standardized Approach, whereas the reportable Total Capital ratios were the lower derived under the Basel III Advanced Approaches framework. Citibank’s reportable Common Equity Tier 1 Capital, Tier 1 Capital and Total Capital ratios were the lower derived under the Basel III Standardized Approach.

N/A  Not applicable