Other Comprehensive Income - Comprehensive Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Pre Tax Amount
Total other comprehensive income (loss)	$ 403,620	$ (468,830)
Tax (Expense) Benefit
Total other comprehensive income (loss)	(90,292)	112,872
After Tax Amount
Before reclassifications	48,779	(353,524)
Less: reclassification adjustments	(264,549)	2,434
Total other comprehensive income (loss)	313,328	(355,958)
Total realized gain, net of tax	41,200
Balance of gain after amortization, net of tax		3,600
Change in fair value of securities available for sale
Pre Tax Amount
Before reclassifications	42,301	(465,532)
Less: reclassification adjustments	(333,170)	(2,172)
Total other comprehensive income (loss)	375,471	(463,360)
Tax (Expense) Benefit
Before reclassifications	(8,810)	112,008
Less: reclassification adjustments	74,630	673
Total other comprehensive income (loss)	(83,440)	111,335
After Tax Amount
Before reclassifications	33,491	(353,524)
Less: reclassification adjustments	(258,540)	(1,499)
Total other comprehensive income (loss)	292,031	(352,025)
Unrealized gains (losses) on cash flow hedges:
Pre Tax Amount
Before reclassifications	19,746	0
Less: reclassification adjustments	(8,905)	5,298
Total other comprehensive income (loss)	28,651	(5,298)
Tax (Expense) Benefit
Before reclassifications	(4,458)	0
Less: reclassification adjustments	2,515	(1,489)
Total other comprehensive income (loss)	(6,973)	1,489
After Tax Amount
Before reclassifications	15,288	0
Less: reclassification adjustments	(6,390)	3,809
Total other comprehensive income (loss)	21,678	(3,809)
Defined benefit pension plans:
Pre Tax Amount
Total other comprehensive income (loss)	(502)	(172)
Tax (Expense) Benefit
Total other comprehensive income (loss)	121	48
After Tax Amount
Before reclassifications	0	0
Less: reclassification adjustments	381	124
Total other comprehensive income (loss)	(381)	(124)
Change in actuarial net loss
Pre Tax Amount
Before reclassifications	0	0
Tax (Expense) Benefit
Before reclassifications	0	0
After Tax Amount
Before reclassifications	0	0
Less: amortization of actuarial net loss
Pre Tax Amount
Less: reclassification adjustments	(2,468)	(2,798)
Tax (Expense) Benefit
Less: reclassification adjustments	697	787
After Tax Amount
Less: reclassification adjustments	(1,771)	(2,011)
Less: accretion of prior service credit
Pre Tax Amount
Less: reclassification adjustments	2,970	2,970
Tax (Expense) Benefit
Less: reclassification adjustments	(818)	(835)
After Tax Amount
Less: reclassification adjustments	$ 2,152	$ 2,135