Comprehensive Income - Components of Other Comprehensive Income (Loss) and Amounts Reclassified from Accumulated Other Comprehensive Income (Loss) to Net Income (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, before tax			$ (172,054,000)	$ (85,143,000)
Unrealized holding losses, net, before tax			(576,266,000)	(57,388,000)
Foreign currency translation adjustment, before tax			(14,564,000)	(1,246,000)
Unrealized gains (losses) on cash flow hedges			(429,310,000)	(821,000)
Total other comprehensive income (loss) before reclassifications, before tax			(1,020,140,000)	(57,813,000)
Amortization of unrealized holding losses on held-to-maturity securities			1,766,000	3,333,000
Gains realized in net income				(8,000)
Accretion of net gain on terminated cash flow hedges, before tax			(90,000)	(90,000)
Net yield adjustment from cash flow hedges currently in effect, before tax			(35,500,000)	(206,713,000)
Amortization of prior service credit, before tax			(1,692,000)	(3,139,000)
Amortization of actuarial losses, before tax			13,810,000	65,792,000
Total other comprehensive income (loss), before tax			(1,041,846,000)	(198,638,000)
Ending balance, before tax	$ (1,213,900,000)	$ (283,781,000)	(1,213,900,000)	(283,781,000)
Beginning balance, tax			44,476,000	22,111,000
Unrealized holding losses, net, tax			149,186,000	15,124,000
Foreign currency translation adjustment, tax			3,293,000	360,000
Unrealized [losses] on cash flow hedges			111,150,000	(214,000)
Total other comprehensive income (loss) before reclassifications, tax			263,629,000	15,270,000
Amortization of unrealized holding losses on held-to-maturity securities, tax			(456,000)	(871,000)
Gains realized in net income, tax				2,000
Accretion of net gain on terminated cash flow hedges, tax			24,000	24,000
Net yield adjustment from cash flow hedges currently in effect, tax			9,192,000	53,997,000
Amortization of prior service credit, tax			413,000	860,000
Amortization of actuarial losses, tax			(3,371,000)	(18,031,000)
Total other comprehensive income (loss), tax			269,431,000	51,251,000
Ending balance, tax	313,907,000	73,362,000	313,907,000	73,362,000
Beginning balance, net of tax			(127,578,000)	(63,032,000)
Unrealized holding losses, net of tax			(427,080,000)	(42,264,000)
Foreign currency translation adjustments	(5,359,000)	(1,579,000)	(11,271,000)	(886,000)
Unrealized losses on cash flow hedges, net of tax			(318,160,000)	607,000
Total other comprehensive income (loss) before reclassifications, net of tax			(756,511,000)	(42,543,000)
Amortization of unrealized holding losses on held-to-maturity securities			1,310,000	2,462,000
Gains realized in net income, net of tax				(6,000)
Accretion of net gain on terminated cash flow hedges, net of tax			(66,000)	(66,000)
Net yield adjustment from cash flow hedges currently in effect, net of tax			(26,308,000)	(152,716,000)
Amortization of prior service credit, net of tax			(1,279,000)	(2,279,000)
Amortization of actuarial losses, net of tax			10,439,000	47,761,000
Total other comprehensive income (loss)	(393,503,000)	(33,445,000)	(772,415,000)	(147,387,000)
Ending balance, net of tax	(899,993,000)	(210,419,000)	(899,993,000)	(210,419,000)
Investment Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, before tax			104,691,000	195,386,000
Unrealized holding losses, net, before tax			(576,266,000)	(57,388,000)
Total other comprehensive income (loss) before reclassifications, before tax			(576,266,000)	(57,388,000)
Amortization of unrealized holding losses on held-to-maturity securities			1,766,000	3,333,000
Gains realized in net income				(8,000)
Total other comprehensive income (loss), before tax			(574,500,000)	(54,063,000)
Ending balance, before tax	(469,809,000)	141,323,000	(469,809,000)	141,323,000
Total other comprehensive income (loss)			(425,770,000)
Defined Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, before tax			(360,276,000)	(650,087,000)
Amortization of prior service credit, before tax			(1,692,000)	(3,139,000)
Amortization of actuarial losses, before tax			13,810,000	65,792,000
Total other comprehensive income (loss), before tax			12,118,000	62,653,000
Ending balance, before tax	(348,158,000)	(587,434,000)	(348,158,000)	(587,434,000)
Total other comprehensive income (loss)			9,160,000
Other [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, before tax			83,531,000	369,558,000
Foreign currency translation adjustment, before tax			(14,564,000)	(1,246,000)
Unrealized gains (losses) on cash flow hedges			(429,310,000)	(821,000)
Total other comprehensive income (loss) before reclassifications, before tax			(443,874,000)	(425,000)
Accretion of net gain on terminated cash flow hedges, before tax			(90,000)	(90,000)
Net yield adjustment from cash flow hedges currently in effect, before tax			(35,500,000)	(206,713,000)
Total other comprehensive income (loss), before tax			(479,464,000)	(207,228,000)
Ending balance, before tax	$ (395,933,000)	$ 162,330,000	$ (395,933,000)	$ 162,330,000