Share Repurchase Plan (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Mar. 21, 2022
Equity, Class of Treasury Stock [Line Items]
Repurchase of S&T Stock (in shares)	151,220		151,220
Cost to repurchase common shares	$ 4,153,000		$ 4,153,000
New Share Repurchase Plan
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount					$ 50,000,000
Stock repurchase program, remaining authorized repurchase amount	$ 33,300,000		$ 33,300,000
Repurchase of S&T Stock (in shares)	151,220	0	151,220	0
Cost to repurchase common shares	$ 4,200,000		$ 4,200,000
Cost to repurchase common shares (in dollars per share)	$ 27.46		$ 27.46