v3.25.2
Regulatory Capital (Details)
$ in Millions
Jun. 30, 2025
USD ($)
Dec. 31, 2024
USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]    
Retained Earnings (Accumulated Deficit) $ 1,191.2 $ 1,166.4
Total risk-based capital:    
Actual, Amount $ 3,109.7 $ 2,962.8
Actual, Ratio 0.1649 0.1438
Minimum Required for Capital Adequacy Purposes, Amount $ 1,508.4 $ 1,647.8
Minimum Required for Capital Adequacy Purposes, Ratio 0.0800 0.0800
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Amount $ 1,979.8 $ 2,162.8
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Ratio 10.50% 10.50%
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Amount $ 1,885.5 $ 2,059.8
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Ratio 0.1000 0.1000
Banking Regulation, Common Equity Tier One Risk-Based Capital, Capital Adequacy, Minimum $ 848.5 $ 926.9
Tier 1 risk-based capital:    
Actual, Amount $ 2,532.0 $ 2,504.0
Actual, Ratio 0.1343 0.1216
Minimum Required for Capital Adequacy Purposes, Amount $ 1,131.3 $ 1,235.9
Minimum Required for Capital Adequacy Purposes, Ratio 0.0600 0.0600
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Amount $ 1,602.7 $ 1,750.8
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Ratio 8.50% 8.50%
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Amount $ 1,508.4 $ 1,647.8
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Ratio 0.0800 0.0800
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Well Capitalized, Minimum 0.0650 0.0650
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Capital Adequacy, Minimum 0.0450 0.0450
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Actual 0.1343 0.1216
Banking Regulation, Common Equity Tier One Risk-Based Capital, Well Capitalized, Minimum $ 1,225.6 $ 1,338.8
Banking Regulation, Common Equity Tier One Risk-Based Capital, Actual 2,532.0 2,504.0
Common equity tier 1 risk-based capital:    
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Amount $ 1,319.8 $ 1,441.8
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Ratio 7.00% 7.00%
Leverage capital ratio:    
Actual, Amount $ 2,532.0 $ 2,504.0
Actual, Ratio 0.0937 0.0871
Banking Regulation, Tier One Leverage Capital, Capital Adequacy, Minimum $ 1,080.9 $ 1,149.4
Capital Adequacy Purposes and Conservation Buffer, Ratio 0.0400 0.0400
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Amount $ 1,351.1 $ 1,436.8
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Ratio 0.0500 0.0500
FIB    
Total risk-based capital:    
Actual, Amount $ 2,725.4 $ 2,691.5
Actual, Ratio 0.1449 0.1310
Minimum Required for Capital Adequacy Purposes, Amount $ 1,504.4 $ 1,644.1
Minimum Required for Capital Adequacy Purposes, Ratio 0.0800 0.0800
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Amount $ 1,974.5 $ 2,157.9
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Ratio 10.50% 10.50%
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Amount $ 1,880.5 $ 2,055.2
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Ratio 0.1000 0.1000
Banking Regulation, Common Equity Tier One Risk-Based Capital, Capital Adequacy, Minimum $ 846.2 $ 924.8
Tier 1 risk-based capital:    
Actual, Amount $ 2,510.3 $ 2,490.3
Actual, Ratio 0.1335 0.1212
Minimum Required for Capital Adequacy Purposes, Amount $ 1,128.3 $ 1,233.1
Minimum Required for Capital Adequacy Purposes, Ratio 0.0600 0.0600
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Amount $ 1,598.4 $ 1,746.9
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Ratio 8.50% 8.50%
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Amount $ 1,504.4 $ 1,644.1
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Ratio 0.0800 0.0800
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Well Capitalized, Minimum 0.0650 0.0650
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Capital Adequacy, Minimum 0.0450 0.0450
Banking Regulation, Common Equity Tier One Risk-Based Capital Ratio, Actual 0.1335 0.1212
Banking Regulation, Common Equity Tier One Risk-Based Capital, Well Capitalized, Minimum $ 1,222.3 $ 1,335.8
Banking Regulation, Common Equity Tier One Risk-Based Capital, Actual 2,510.3 2,490.3
Common equity tier 1 risk-based capital:    
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Amount $ 1,316.3 $ 1,438.6
For Capital Adequacy Purposes Plus Capital Conservation Buffer, Ratio 7.00% 7.00%
Leverage capital ratio:    
Actual, Amount $ 2,510.3 $ 2,490.3
Actual, Ratio 0.0931 0.0868
Banking Regulation, Tier One Leverage Capital, Capital Adequacy, Minimum $ 1,079.0 $ 1,147.5
Capital Adequacy Purposes and Conservation Buffer, Ratio 0.0400 0.0400
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Amount $ 1,348.7 $ 1,434.4
Minimum to Be Well Capitalized Under Prompt Corrective Action Requirements, Ratio 0.0500 0.0500