Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Statement of Comprehensive Income [Abstract]
Net income		$ 62,644	$ 61,776	$ 123,891	$ 114,873
Other comprehensive (loss) income, net of tax
Other Comprehensive Income (Loss), Securities, Available-for-sale, Adjustment, after Tax		(11,451)	(23,734)	5,617	(86,290)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax		(5,448)	(7,649)	4,715	(25,599)
Net change in other comprehensive income for defined benefit postretirement plans	[1]	(91)	121	(183)	242
Total other comprehensive (loss) income		(16,990)	(31,262)	10,149	(111,647)
Total comprehensive income		$ 45,654	$ 30,514	$ 134,040	$ 3,226

[1] The amortization of prior service costs is included in the computation of net periodic pension cost as disclosed in Note 13 - Employee Benefit Plans within the Notes to the Consolidated Financial Statements included in Item 8 of the Company's 2022 Form 10-K.