Regulatory Matters (Tables)

12 Months Ended

Dec. 31, 2025

Regulatory Capital Requirements Under Banking Regulations [Abstract]

Summary of Risk-Based Capital Amounts and Ratios

The following table summarizes risk-based capital amounts and ratios for S&T and S&T Bank:

	Actual				Minimum Regulatory Capital Requirements				To be Well Capitalized Under Prompt Corrective Action Provisions
(dollars in thousands)	Amount		Ratio		Amount		Ratio		Amount		Ratio
As of December 31, 2025
Leverage Ratio
S&T	$	1,154,736	12.18	%	$	379,316	4.00	%	$	474,146	5.00	%
S&T Bank	1,128,495		11.91	%	379,139		4.00	%	473,923		5.00	%
Common Equity Tier 1 ratio
S&T	1,130,736		14.32	%	355,419		4.50	%	513,383		6.50	%
S&T Bank	1,128,495		14.30	%	355,206		4.50	%	513,076		6.50	%
Tier 1 Capital (to Risk-Weighted Assets)
S&T	1,154,736		14.62	%	473,892		6.00	%	631,856		8.00	%
S&T Bank	1,128,495		14.30	%	473,608		6.00	%	631,478		8.00	%
Total Capital (to Risk-Weighted Assets)
S&T	1,278,474		16.19	%	631,856		8.00	%	789,821		10.00	%
S&T Bank	1,252,175		15.86	%	631,478		8.00	%	789,347		10.00	%
As of December 31, 2024
Leverage Ratio
S&T	$	1,112,126	11.98	%	$	371,211	4.00	%	$	464,014	5.00	%
S&T Bank	1,060,010		11.43	%	371,002		4.00	%	463,752		5.00	%
Common Equity Tier 1 ratio
S&T	1,088,126		14.58	%	335,888		4.50	%	485,172		6.50	%
S&T Bank	1,060,010		14.21	%	335,722		4.50	%	484,932		6.50	%
Tier 1 Capital (to Risk-Weighted Assets)
S&T	1,112,126		14.90	%	447,851		6.00	%	597,134		8.00	%
S&T Bank	1,060,010		14.21	%	447,629		6.00	%	596,839		8.00	%
Total Capital (to Risk-Weighted Assets)
S&T	1,230,497		16.49	%	597,134		8.00	%	746,418		10.00	%
S&T Bank	1,178,335		15.79	%	596,839		8.00	%	746,049		10.00	%