Comprehensive Income - Components of Other Comprehensive Income (Loss) and Amounts Reclassified from Accumulated Other Comprehensive Income (Loss) to Net Income (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, before tax	$ (172,054)	$ (85,143)	$ (279,959)
Unrealized holding gains (losses), net, before tax	(550,648)	(95,114)	141,081
Foreign currency translation adjustment, before tax	(7,845)	(1,218)	2,724
Unrealized gain (losses) on cash flow hedges	(461,033)	(32,292)	505,042
Current year benefit plans gains (loss), before tax	71,262	(206,274)	(238,218)
Total other comprehensive income (loss) before reclassifications, before tax	(948,264)	77,650	410,629
Amortization of unrealized holding losses on held-to-maturity securities	1,765	4,427	3,606
Gains (losses) realized in net income		(8)	(2)
Accretion of net gain on terminated cash flow hedges, before tax	(120)	(120)	(125)
Net yield adjustment from cash flow hedges currently in effect, before tax	36,338	(252,397)	(271,971)
Amortization of prior service credit, before tax	(2,256)	(4,185)	(4,181)
Amortization of actuarial losses, before tax	18,414	87,722	56,860
Total other comprehensive income (loss), before tax	(894,123)	(86,911)	194,816
Ending balance, before tax	(1,066,177)	(172,054)	(85,143)
Beginning balance, tax	44,476	22,111	73,279
Unrealized holding gains (losses), net, tax	142,546	24,870	(36,498)
Foreign currency translation adjustment, tax	2,058	356	(440)
Unrealized gain (losses) on cash flow hedges	119,360	8,410	(130,432)
Current year benefit plans gains (loss),tax	(18,309)	54,016	60,208
Total other comprehensive income (loss) before reclassifications, tax	245,655	(20,380)	(107,162)
Amortization of unrealized holding losses on held-to-maturity securities, tax	(456)	(1,154)	(966)
Gains (losses) realized in net income, tax		2	1
Accretion of net gain on terminated cash flow hedges, tax	31	32	34
Net yield adjustment from cash flow hedges currently in effect, tax	(9,407)	65,741	70,239
Amortization of prior service credit, tax	579	1,095	1,057
Amortization of actuarial losses, tax	(4,731)	(22,971)	(14,371)
Total other comprehensive income (loss), tax	231,671	22,365	(51,168)
Ending balance, tax	276,147	44,476	22,111
Current year benefit plans gains loss, tax	18,309	(54,016)	(60,208)
Beginning balance, net of tax	(127,578)	(63,032)	(206,680)
Unrealized holding gains (losses), net of tax	(408,102)	(70,244)	104,583
Foreign currency translation adjustments	(5,787)	(862)	2,284
Unrealized gain (losses) on cash flow hedges net of tax	(341,673)	(23,882)	374,610
Current year benefit plans gains (losses) , net of tax	52,953	152,258	(178,010)
Total other comprehensive income (loss) before reclassifications, net of tax	(702,609)	57,270	303,467
Amortization of unrealized holding losses on held-to-maturity securities	1,309	3,273	2,640
Gains (losses) realized in net income, net of tax		(6)	(1)
Accretion of net gain on terminated cash flow hedges, net of tax	(89)	(88)	(91)
Net yield adjustment from cash flow hedges currently in effect, net of tax	26,931	(186,656)	(201,732)
Amortization of prior service credit, net of tax	(1,677)	(3,090)	(3,124)
Amortization of actuarial losses, net of tax	13,683	64,751	42,489
Total other comprehensive income (loss)	(662,452)	(64,546)	143,648
Ending balance, net of tax	(790,030)	(127,578)	(63,032)
Investment Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, before tax	104,691	195,386	50,701
Unrealized holding gains (losses), net, before tax	(550,648)	(95,114)	141,081
Total other comprehensive income (loss) before reclassifications, before tax	(550,648)	(95,114)	141,081
Amortization of unrealized holding losses on held-to-maturity securities	1,765	4,427	3,606
Gains (losses) realized in net income		(8)	(2)
Total other comprehensive income (loss), before tax	(548,883)	(90,695)	144,685
Ending balance, before tax	(444,192)	104,691	195,386
Total other comprehensive income (loss)	(406,793)	(66,977)	107,222
Defined Benefit Plans [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, before tax	(360,276)	(650,087)	(464,548)
Current year benefit plans gains (loss), before tax	71,262	206,274	(238,218)
Total other comprehensive income (loss) before reclassifications, before tax	71,262	206,274	(238,218)
Amortization of prior service credit, before tax	(2,256)	(4,185)	(4,181)
Amortization of actuarial losses, before tax	18,414	87,722	56,860
Total other comprehensive income (loss), before tax	87,420	289,811	(185,539)
Ending balance, before tax	(272,856)	(360,276)	(650,087)
Total other comprehensive income (loss)	64,959	213,919	(138,645)
Other [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning balance, before tax	83,531	369,558	133,888
Foreign currency translation adjustment, before tax	(7,845)	(1,218)	2,724
Unrealized gain (losses) on cash flow hedges	(461,033)	(32,292)	505,042
Total other comprehensive income (loss) before reclassifications, before tax	(468,878)	(33,510)	507,766
Accretion of net gain on terminated cash flow hedges, before tax	(120)	(120)	(125)
Net yield adjustment from cash flow hedges currently in effect, before tax	36,338	(252,397)	(271,971)
Total other comprehensive income (loss), before tax	(432,660)	(286,027)	235,670
Ending balance, before tax	$ (349,129)	$ 83,531	$ 369,558