v3.26.1
Shareholders' Equity - Net Change in Components of Accumulated Other Comprehensive Income (Loss) and the Related Tax Effects (Details) - USD ($)
$ in Thousands
 3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Other comprehensive income (loss), before tax amount $ (19,796) $ 24,285 $ (38,210) $ 70,893
Other Comprehensive Income (Loss), Tax, Total 4,950 (6,072) 9,553 (17,723)
Other comprehensive income (loss), before reclassifications, net of tax amount     (30,057) 49,082
Reclassification from accumulated other comprehensive income, current period, net of tax amount     1,400 4,088
Other comprehensive income (loss), net of tax amount (14,846) 18,213 (28,657) 53,170
Securities Available for Sale and Transferred Securities [Member]        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Other comprehensive income (loss), before reclassifications, before tax amount (15,035) 13,992 (31,721) 46,591
Other comprehensive income (loss), change in net unrealized holding loss on securities transferred to held to maturity, before tax amount 2,600 3,450 5,559 6,875
Other comprehensive income (loss), before tax amount (12,435) 17,442 (26,162) 53,466
Other comprehensive income (loss), before reclassifications, tax (expense) benefit 3,760 (3,499) 7,931 (11,648)
Other comprehensive income (loss), change in net unrealized holding loss on securities transferred to held to maturity, tax (expense) benefit (650) (863) (1,390) (1,719)
Other Comprehensive Income (Loss), Tax, Total 3,110 (4,362) 6,541 (13,367)
Other comprehensive income (loss), before reclassifications, net of tax amount (11,275) 10,493 (23,790) 34,943
Other comprehensive income (loss), change in net unrealized holding loss on securities transferred to held to maturity, net of tax amount 1,950 2,587 4,169 5,156
Other comprehensive income (loss), net of tax amount (9,325) 13,080 (19,621) 40,099
Net Change in Prior Service Costs [Member]        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Reclassification from accumulated other comprehensive income, current period, before tax amount 0 3 0 7
Reclassification from accumulated other comprehensive income, current period, tax (expense) benefit 0 0 0 (1)
Reclassification from accumulated other comprehensive income, current period, net of tax amount 0 3 0 6
Recognized Net Loss Due to Lump Sum Settlements [Member]        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Reclassification from accumulated other comprehensive income, current period, before tax amount (31) 0 (31) (50)
Reclassification from accumulated other comprehensive income, current period, tax (expense) benefit 8 0 8 12
Reclassification from accumulated other comprehensive income, current period, net of tax amount (23) 0 (23) (38)
Change in Net Actuarial Loss [Member]        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Reclassification from accumulated other comprehensive income, current period, before tax amount 73 61 158 132
Reclassification from accumulated other comprehensive income, current period, tax (expense) benefit (19) (16) (40) (33)
Reclassification from accumulated other comprehensive income, current period, net of tax amount 54 45 118 99
Pension and Other Postretirement Benefit Plans [Member]        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Reclassification from accumulated other comprehensive income, current period, before tax amount 42 64 127 89
Reclassification from accumulated other comprehensive income, current period, tax (expense) benefit (11) (16) (32) (22)
Reclassification from accumulated other comprehensive income, current period, net of tax amount 31 48 95 67
Cash Flow Hedge Derivatives [Member]        
Accumulated Other Comprehensive Income (Loss) [Line Items]        
Other comprehensive income (loss), before reclassifications, before tax amount (8,208) 4,098 (13,915) 11,977
Reclassification from accumulated other comprehensive income, current period, before tax amount 805 2,681 1,740 5,361
Other comprehensive income (loss), before tax amount (7,403) 6,779 (12,175) 17,338
Other comprehensive income (loss), before reclassifications, tax (expense) benefit 2,052 (1,024) 3,479 (2,994)
Reclassification from accumulated other comprehensive income, current period, tax (expense) benefit (201) (670) (435) (1,340)
Other Comprehensive Income (Loss), Tax, Total 1,851 (1,694) 3,044 (4,334)
Other comprehensive income (loss), before reclassifications, net of tax amount (6,156) 3,074 (10,436) 8,983
Reclassification from accumulated other comprehensive income, current period, net of tax amount 604 2,011 1,305 4,021
Other comprehensive income (loss), net of tax amount $ (5,552) $ 5,085 $ (9,131) $ 13,004