Parent Company Condensed Financial Information - Balance Sheets (Details) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
ASSETS
Cash	$ 163,436	$ 244,820
Investments in:
Other assets	219,115	262,342
Total Assets	9,870,980	9,657,972
LIABILITIES
Other liabilities	182,979	244,247
Total Liabilities	8,407,103	8,277,678
Total Shareholders’ Equity	1,463,877	1,380,294	$ 1,283,445	$ 1,184,659
Total Liabilities and Shareholders’ Equity	9,870,980	9,657,972
S&T
ASSETS
Cash	11,962	39,304
Investments in:
Bank subsidiary	1,461,635	1,352,177
Nonbank subsidiaries	4,462	4,169
Other assets	11,329	9,666
Total Assets	1,489,388	1,405,316
LIABILITIES
Long-term debt	24,572	24,515
Other liabilities	939	507
Total Liabilities	25,511	25,022
Total Shareholders’ Equity	1,463,877	1,380,294
Total Liabilities and Shareholders’ Equity	$ 1,489,388	$ 1,405,316