Investment Securities - Summary of Continuous Unrealized Loss Position of Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Schedule of Investments [Line Items]
Fair Value, Less Than 12 Months, Available-for-sale	$ 764,181	$ 1,736,843
Gross Unrealized Holding Loss, Less than 12 Months, Available-for-sale	43,522	193,815
Fair Value, 12 Months or Longer, Available-for-sale	2,430,213	1,514,552
Gross Unrealized Holding Losses, 12 Months or Longer, Available-for-sale	416,259	306,377
Fair Value, Available-for-sale	3,194,394	3,251,395
Gross Unrealized Holding Losses, Available-for-sale	459,781	500,192
Fair Value, Less Than 12 Months, Held-to-maturity	298,387	1,057,070
Gross Unrealized Holding Loss, Less than 12 Months, Held-to-maturity	7,741	145,162
Fair Value, 12 Months or Longer, Held-to-maturity	1,751,596	1,039,955
Gross Unrealized Holding Losses, 12 Months or Longer, Held-to-maturity	362,074	254,465
Fair Value, Held-to-maturity	2,049,983	2,097,025
Gross Unrealized Holding Losses, Held-to-maturity	369,815	399,627
CMO/REMIC [Member]
Schedule of Investments [Line Items]
Fair Value, Less Than 12 Months, Available-for-sale	6,062	54,005
Gross Unrealized Holding Loss, Less than 12 Months, Available-for-sale	148	4,796
Fair Value, 12 Months or Longer, Available-for-sale	423,357	385,295
Gross Unrealized Holding Losses, 12 Months or Longer, Available-for-sale	97,352	91,170
Fair Value, Available-for-sale	429,419	439,300
Gross Unrealized Holding Losses, Available-for-sale	97,500	95,966
Fair Value, Less Than 12 Months, Held-to-maturity	48,202	376,540
Gross Unrealized Holding Loss, Less than 12 Months, Held-to-maturity	2,033	60,598
Fair Value, 12 Months or Longer, Held-to-maturity	639,623	319,076
Gross Unrealized Holding Losses, 12 Months or Longer, Held-to-maturity	132,741	71,132
Fair Value, Held-to-maturity	687,825	695,616
Gross Unrealized Holding Losses, Held-to-maturity	134,774	131,730
Government Agency/GSE [Member]
Schedule of Investments [Line Items]
Fair Value, Less Than 12 Months, Held-to-maturity	23,225	179,348
Gross Unrealized Holding Loss, Less than 12 Months, Held-to-maturity	579	39,866
Fair Value, 12 Months or Longer, Held-to-maturity	419,597	255,080
Gross Unrealized Holding Losses, 12 Months or Longer, Held-to-maturity	99,917	74,477
Fair Value, Held-to-maturity	442,822	434,428
Gross Unrealized Holding Losses, Held-to-maturity	100,496	114,343
Mortgage-backed Securities [Member]
Schedule of Investments [Line Items]
Fair Value, Less Than 12 Months, Available-for-sale	753,978	1,658,331
Gross Unrealized Holding Loss, Less than 12 Months, Available-for-sale	43,323	187,842
Fair Value, 12 Months or Longer, Available-for-sale	1,992,196	1,129,257
Gross Unrealized Holding Losses, 12 Months or Longer, Available-for-sale	318,240	215,207
Fair Value, Available-for-sale	2,746,174	2,787,588
Gross Unrealized Holding Losses, Available-for-sale	361,563	403,049
Fair Value, Less Than 12 Months, Held-to-maturity	128,307	188,480
Gross Unrealized Holding Loss, Less than 12 Months, Held-to-maturity	2,858	9,042
Fair Value, 12 Months or Longer, Held-to-maturity	471,641	412,449
Gross Unrealized Holding Losses, 12 Months or Longer, Held-to-maturity	94,960	96,825
Fair Value, Held-to-maturity	599,948	600,929
Gross Unrealized Holding Losses, Held-to-maturity	97,818	105,867
Municipal Bonds [Member]
Schedule of Investments [Line Items]
Fair Value, Less Than 12 Months, Available-for-sale	4,141	24,507
Gross Unrealized Holding Loss, Less than 12 Months, Available-for-sale	51	1,177
Fair Value, 12 Months or Longer, Available-for-sale	14,660	0
Gross Unrealized Holding Losses, 12 Months or Longer, Available-for-sale	667	0
Fair Value, Available-for-sale	18,801	24,507
Gross Unrealized Holding Losses, Available-for-sale	718	1,177
Fair Value, Less Than 12 Months, Held-to-maturity	98,653	312,702
Gross Unrealized Holding Loss, Less than 12 Months, Held-to-maturity	2,271	35,656
Fair Value, 12 Months or Longer, Held-to-maturity	220,735	53,350
Gross Unrealized Holding Losses, 12 Months or Longer, Held-to-maturity	34,456	12,031
Fair Value, Held-to-maturity	319,388	366,052
Gross Unrealized Holding Losses, Held-to-maturity	$ 36,727	$ 47,687

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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