Stockholders' Equity - Accumulated Other Comprehensive (Loss) Income (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2023
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	$ 998,907	$ 785,328
Realized loss on sale of securities, net of tax		1,616
Realized loss due to settlement and curtailment, net of tax	1,858	1,858
Other comprehensive (loss) income, net of reclassifications and tax		(20,134)
Ending balance	993,219	993,219
Accumulated Other Comprehensive Loss
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance	(118,920)	(127,136)
Realized loss due to settlement and curtailment, net of tax	1,858	1,858
Ending balance	(143,796)	(143,796)
Unrealized (Loss) Gain on Securities
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		(129,896)
Realized loss on sale of securities, net of tax		1,616
Realized loss due to settlement and curtailment, net of tax		0
Other comprehensive (loss) income, net of reclassifications and tax		(19,824)
Ending balance	(148,104)	(148,104)
Unrecognized Net Pension and Postretirement Costs
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		(1,633)
Realized loss on sale of securities, net of tax		0
Realized loss due to settlement and curtailment, net of tax		1,858
Other comprehensive (loss) income, net of reclassifications and tax		(180)
Ending balance	45	45
Unrealized Gain (Loss) on Cash Flow Hedges
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Beginning balance		4,393
Realized loss on sale of securities, net of tax		0
Realized loss due to settlement and curtailment, net of tax		0
Other comprehensive (loss) income, net of reclassifications and tax		(130)
Ending balance	$ 4,263	$ 4,263