Regulatory Capital (Tables)

12 Months Ended

Dec. 31, 2020

Banking and Thrift, Other Disclosures [Abstract]

Regulatory Capital Ratios

The following tables present the regulatory capital requirements under the applicable Basel III based U.S. capital rules:

Flagstar Bancorp	Actual				Minimum Capital Ratios				Well-Capitalized Under Prompt Corrective Action Provisions
	Amount		Ratio		Amount		Ratio		Amount		Ratio
	(Dollars in millions)
December 31, 2020
Tier 1 capital (to adjusted avg. total assets)	$	2,270	7.71	%	$	1,178	4.0	%	$	1,472	5.0	%
Common equity Tier 1 capital (to RWA)	2,030		9.15	%	999		4.5	%	1,442		6.5	%
Tier 1 capital (to RWA)	2,270		10.23	%	1,331		6.0	%	1,775		8.0	%
Total capital (to RWA)	2,638		11.89	%	1,775		8.0	%	2,219		10.0	%
December 31, 2019
Tier 1 capital (to adjusted avg. total assets)	$	1,720	7.57	%	$	909	4.0	%	$	1,136	5.0	%
Common equity Tier 1 capital (to RWA)	1,480		9.32	%	715		4.5	%	1,033		6.5	%
Tier 1 capital (to RWA)	1,720		10.83	%	953		6.0	%	1,271		8.0	%
Total capital (to RWA)	1,830		11.52	%	1,271		8.0	%	1,589		10.0	%

Flagstar Bank	Actual				Minimum Capital Ratios				Well-Capitalized Under Prompt Corrective Action Provisions
	Amount		Ratio		Amount		Ratio		Amount		Ratio
	(Dollars in millions)
December 31, 2020
Tier 1 capital (to adjusted avg. total assets)	$	2,390	8.12	%	$	1,177	4.0	%	$	1,472	5.0	%
Common equity Tier 1 capital (to RWA)	2,390		10.77	%	999		4.5	%	1,443		6.5	%
Tier 1 capital (to RWA)	2,390		10.77	%	1,332		6.0	%	1,775		8.0	%
Total capital (to RWA)	2,608		11.75	%	1,775		8.0	%	2,219		10.0	%
December 31, 2019
Tier 1 capital (to adjusted avg. total assets)	$	1,752	7.71	%	$	909	4.0	%	$	1,136	5.0	%
Common equity Tier 1 capital (to RWA)	1,752		11.04	%	714		4.5	%	1,032		6.5	%
Tier 1 capital (to RWA)	1,752		11.04	%	952		6.0	%	1,270		8.0	%
Total capital (to RWA)	1,862		11.73	%	1,270		8.0	%	1,587		10.0	%