Regulatory Capital (Tables)

12 Months Ended

Dec. 31, 2022

Broker-Dealer, Net Capital Requirement, SEC Regulation [Abstract]

Summary of Capital Position

The following is a summary of the capital position of the Corporation and Comerica Bank, its principal banking subsidiary.

(dollar amounts in millions)	Comerica Incorporated (Consolidated)			Comerica Bank
December 31, 2022
CET1 capital (minimum $3.5 billion (Consolidated))	$	7,884		$	7,801
Tier 1 capital (minimum $4.7 billion (Consolidated))	8,278			7,801
Total capital (minimum $6.3 billion (Consolidated))	9,817			9,190
Risk-weighted assets	78,871			78,781
Average assets (fourth quarter)	86,726			86,608
CET1 capital to risk-weighted assets (minimum-4.5%)	10.00		%	9.90		%
Tier 1 capital to risk-weighted assets (minimum-6.0%)	10.50			9.90
Total capital to risk-weighted assets (minimum-8.0%)	12.45			11.67
Tier 1 capital to average assets (minimum-4.0%)	9.55			9.01
Capital conservation buffer (minimum-2.5%)	4.45			3.67
December 31, 2021
CET1 capital (minimum $3.1 billion (Consolidated))	$	7,064		$	7,634
Tier 1 capital (minimum $4.2 billion (Consolidated))	7,458			7,634
Total capital (minimum $5.6 billion (Consolidated))	8,608			8,584
Risk-weighted assets	69,708			69,542
Average assets (fourth quarter)	96,417			96,216
CET1 capital to risk-weighted assets (minimum-4.5%)	10.13		%	10.98		%
Tier 1 capital to risk-weighted assets (minimum-6.0%)	10.70			10.98
Total capital to risk-weighted assets (minimum-8.0%)	12.35			12.34
Tier 1 capital to average assets (minimum-4.0%)	7.74			7.93
Capital conservation buffer (minimum-2.5%)	4.35			4.34