Nature of Business	12 Months Ended
Dec. 31, 2011
Nature of Business [Abstract]
Nature of Business	Note 1 — Nature of Business Flagstar Bancorp, Inc. (“Flagstar” or the “Company”), is the holding company for Flagstar Bank, FSB (the “Bank”), a federally chartered stock savings bank founded in 1987. With $13.6 billion in assets at December 31, 2011, the Company is the largest savings institution and banking institution headquartered in Michigan and is the largest publicly held savings bank headquartered in the Midwest. The Company is a full-service financial services company, offering a range of products and services to consumers, businesses, and homeowners. The Company currently operates 113 branches in Michigan and 27 home lending centers in 13 states. During the fourth quarter 2011, the Company completed the sale or lease of 27 banking centers in Georgia to PNC Bank, N.A., part of The PNC Financial Services Group, Inc. (“PNC”) and 22 retail banking centers in Indiana to First Financial Bank, N.A. (“First Financial”). For further information concerning branch sales, refer to Note 2 — Recent Developments — Branch Sales. Originating residential loans nationwide, the Company is one of the leading originators of residential mortgages in the country. The Company also offers consumer products including deposit accounts, standard and jumbo home loans, home equity lines of credit, and personal loans, including auto and boat loans. The Company also offers commercial loans and treasury management services throughout Michigan and through its four commercial banking offices in Massachusetts, Rhode Island and Connecticut. Commercial products include deposit and sweep accounts, telephone banking, term loans and lines of credit, lease financing, government banking products and treasury management services such as remote deposit and merchant services. The Company sells or securitizes most of the mortgage loans that it originates and generally retains the right to service the mortgage loans that it sells. These mortgage-servicing rights (“MSRs”) are occasionally sold by the Company in transactions separate from the sale of the underlying mortgages. The Company may also invest in its loan originations to refine the Company’s leverage ability and to receive the interest spread between earning assets and paying liabilities. The Bank is a member of the Federal Home Loan Bank (“FHLB”) of Indianapolis and is subject to regulation, examination and supervision by the Office of the Comptroller of the Currency (“OCC”) of the United States Department of the Treasury (“U.S. Treasury”). The Bank is also subject to regulation, examination and supervision by the Federal Deposit Insurance Corporation (“FDIC”) and the Consumer Financial Protection Bureau (the “CFPB”). The Bank’s deposits are insured by the FDIC through the Deposit Insurance Fund (“DIF”). The Company is subject to regulation, examination and supervision by the Board of Governors of the Federal Reserve.

Nature of Business

12 Months Ended

Dec. 31, 2011

Note 1 — Nature of Business

Flagstar Bancorp, Inc. (“Flagstar” or the “Company”), is the holding company for Flagstar Bank, FSB (the “Bank”), a federally chartered stock savings bank founded in 1987. With $13.6 billion in assets at December 31, 2011, the Company is the largest savings institution and banking institution headquartered in Michigan and is the largest publicly held savings bank headquartered in the Midwest.

The Company is a full-service financial services company, offering a range of products and services to consumers, businesses, and homeowners. The Company currently operates 113 branches in Michigan and 27 home lending centers in 13 states. During the fourth quarter 2011, the Company completed the sale or lease of 27 banking centers in Georgia to PNC Bank, N.A., part of The PNC Financial Services Group, Inc. (“PNC”) and 22 retail banking centers in Indiana to First Financial Bank, N.A. (“First Financial”). For further information concerning branch sales, refer to Note 2 — Recent Developments — Branch Sales. Originating residential loans nationwide, the Company is one of the leading originators of residential mortgages in the country. The Company also offers consumer products including deposit accounts, standard and jumbo home loans, home equity lines of credit, and personal loans, including auto and boat loans. The Company also offers commercial loans and treasury management services throughout Michigan and through its four commercial banking offices in Massachusetts, Rhode Island and Connecticut. Commercial products include deposit and sweep accounts, telephone banking, term loans and lines of credit, lease financing, government banking products and treasury management services such as remote deposit and merchant services.

The Company sells or securitizes most of the mortgage loans that it originates and generally retains the right to service the mortgage loans that it sells. These mortgage-servicing rights (“MSRs”) are occasionally sold by the Company in transactions separate from the sale of the underlying mortgages. The Company may also invest in its loan originations to refine the Company’s leverage ability and to receive the interest spread between earning assets and paying liabilities.

The Bank is a member of the Federal Home Loan Bank (“FHLB”) of Indianapolis and is subject to regulation, examination and supervision by the Office of the Comptroller of the Currency (“OCC”) of the United States Department of the Treasury (“U.S. Treasury”). The Bank is also subject to regulation, examination and supervision by the Federal Deposit Insurance Corporation (“FDIC”) and the Consumer Financial Protection Bureau (the “CFPB”). The Bank’s deposits are insured by the FDIC through the Deposit Insurance Fund (“DIF”). The Company is subject to regulation, examination and supervision by the Board of Governors of the Federal Reserve.