Securities - Summary of Debt Securities with Unrealized Losses, Segregated by Duration of Unrealized Loss (Detail) $ in Thousands	Jun. 30, 2022 USD ($) Investments	Dec. 31, 2021 USD ($) Investments
Debt Securities, Available-for-sale [Abstract]
Number of investments \| Investments	140	21
Available-for-sale Securities, Less than 12 Months, Fair Value	$ 1,146,136	$ 304,779
Available-for-sale Securities, Less than 12 Months, Unrealized Losses	61,139	1,791
Available-for-sale Securities, 12 Months or Longer, Fair Value	5,705
Available-for-sale Securities, 12 Months or Longer, Unrealized Losses	211
Available-for-sale Securities, Fair Value, Total	1,151,841	304,779
Available-for-sale Securities, Unrealized Losses, Total	$ 61,350	$ 1,791
U.S. Treasuries [Member]
Debt Securities, Available-for-sale [Abstract]
Number of investments \| Investments	58	10
Available-for-sale Securities, Less than 12 Months, Fair Value	$ 1,112,058	$ 298,080
Available-for-sale Securities, Less than 12 Months, Unrealized Losses	58,843	1,766
Available-for-sale Securities, 12 Months or Longer, Fair Value	4,853
Available-for-sale Securities, 12 Months or Longer, Unrealized Losses	144
Available-for-sale Securities, Fair Value, Total	1,116,911	298,080
Available-for-sale Securities, Unrealized Losses, Total	$ 58,987	$ 1,766
U.S. Federal Agencies [Member]
Debt Securities, Available-for-sale [Abstract]
Number of investments \| Investments	2	1
Available-for-sale Securities, Less than 12 Months, Fair Value	$ 363	$ 376
Available-for-sale Securities, Less than 12 Months, Unrealized Losses	1	2
Available-for-sale Securities, Fair Value, Total	363	376
Available-for-sale Securities, Unrealized Losses, Total	$ 1	$ 2
Mortgage Backed Securities [Member]
Debt Securities, Available-for-sale [Abstract]
Number of investments \| Investments	71	7
Available-for-sale Securities, Less than 12 Months, Fair Value	$ 15,971	$ 2,824
Available-for-sale Securities, Less than 12 Months, Unrealized Losses	1,368	14
Available-for-sale Securities, 12 Months or Longer, Fair Value	657
Available-for-sale Securities, 12 Months or Longer, Unrealized Losses	61
Available-for-sale Securities, Fair Value, Total	16,628	2,824
Available-for-sale Securities, Unrealized Losses, Total	$ 1,429	$ 14
States and Political Subdivisions [Member]
Debt Securities, Available-for-sale [Abstract]
Number of investments \| Investments	7	2
Available-for-sale Securities, Less than 12 Months, Fair Value	$ 2,135	$ 505
Available-for-sale Securities, Less than 12 Months, Unrealized Losses	173	3
Available-for-sale Securities, 12 Months or Longer, Fair Value	195
Available-for-sale Securities, 12 Months or Longer, Unrealized Losses	6
Available-for-sale Securities, Fair Value, Total	2,330	505
Available-for-sale Securities, Unrealized Losses, Total	$ 179	$ 3
Asset backed Securities [Member]
Debt Securities, Available-for-sale [Abstract]
Number of investments \| Investments	1
Available-for-sale Securities, Less than 12 Months, Fair Value	$ 12,877
Available-for-sale Securities, Less than 12 Months, Unrealized Losses	486
Available-for-sale Securities, Fair Value, Total	12,877
Available-for-sale Securities, Unrealized Losses, Total	$ 486
Other Securities [Member]
Debt Securities, Available-for-sale [Abstract]
Number of investments \| Investments	1	1
Available-for-sale Securities, Less than 12 Months, Fair Value	$ 2,732	$ 2,994
Available-for-sale Securities, Less than 12 Months, Unrealized Losses	268	6
Available-for-sale Securities, Fair Value, Total	2,732	2,994
Available-for-sale Securities, Unrealized Losses, Total	$ 268	$ 6

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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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Amount of accumulated unrealized loss on 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 12 months or longer, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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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 less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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Amount of accumulated unrealized loss on 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 less than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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