Shareholders' Equity and Regulatory Matters - Detailed AOCI Table (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Accumulated other comprehensive loss, Beginning balance	$ (5,613)
Other comprehensive income before reclassification - AFS	(782)	$ 1,482
Other comprehensive income before reclassification - benefits		(2)
Net current period other comprehensive income	(782)	1,484
Accumulated other comprehensive loss, Ending balance	(6,395)		$ (5,613)
Unrealized Losses on AFS Securities
Accumulated other comprehensive loss, Beginning balance	(5,604)	(10,863)	(10,863)
Other comprehensive income before reclassification - AFS			1,320
Amounts reclassified from AOCI into earnings			3,939
Net current period other comprehensive income			5,259
Accumulated other comprehensive loss, Ending balance			(5,604)
Defined Benefit Plan
Accumulated other comprehensive loss, Beginning balance	(9)	(18)	(18)
Other comprehensive income before reclassification - benefits			9
Net current period other comprehensive income			9
Accumulated other comprehensive loss, Ending balance	(9)		(9)
Accumulated Other Comprehensive Income (Loss)
Accumulated other comprehensive loss, Beginning balance	(5,613)	$ (10,881)	(10,881)
Other comprehensive income before reclassification - AFS and benefits			1,329
Amounts reclassified from AOCI into earnings	(782)		3,939
Net current period other comprehensive income	(782)		5,268
Accumulated other comprehensive loss, Ending balance	(6,395)		(5,613)
Accumulated Other Comprehensive Income (Loss) | Unrealized Losses on AFS Securities
Accumulated other comprehensive loss, Beginning balance	(5,604)
Amounts reclassified from AOCI into earnings	(782)
Net current period other comprehensive income	(782)
Accumulated other comprehensive loss, Ending balance	$ (6,386)		$ (5,604)