Restrictions on Subsidiary Dividends, Loans, or Advances (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Maximum amount available for transfer in the form of loans or advances	$ 579.8	$ 536.1
Outstanding loans or advances	0.0	$ 0.0
Announced stock repurchase program
Amount available for special dividend distribution without approval from SCBFI	180.0
Special dividend for general operating liquidity	$ 154.9

Amount of dividends that can be declared or paid without approval of regulatory agency.

No definition available.

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant