Investment securities - Schedule of Gross Unrealized Losses on Securities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Debt Securities, Available-for-sale [Abstract]
Fair Value, Less than 12 months	$ 928,115	$ 185,695
Unrealized Loss, Less than 12 months	(14,703)	(824)
Fair Value, 12 months or more	102,799	0
Unrealized Loss, 12 months or more	(3,690)	0
Fair Value, Total	1,030,914	185,695
Unrealized Loss, Total	(18,393)	(824)
U.S. government agency securities
Debt Securities, Available-for-sale [Abstract]
Fair Value, Less than 12 months	18,360
Unrealized Loss, Less than 12 months	(171)
Fair Value, 12 months or more	0
Unrealized Loss, 12 months or more	0
Fair Value, Total	18,360
Unrealized Loss, Total	(171)
Mortgage-backed securities - residential
Debt Securities, Available-for-sale [Abstract]
Fair Value, Less than 12 months	871,368	182,012
Unrealized Loss, Less than 12 months	(14,295)	(803)
Fair Value, 12 months or more	102,799	0
Unrealized Loss, 12 months or more	(3,690)	0
Fair Value, Total	974,167	182,012
Unrealized Loss, Total	(17,985)	(803)
Mortgage-backed securities - commercial
Debt Securities, Available-for-sale [Abstract]
Fair Value, Less than 12 months	7,946
Unrealized Loss, Less than 12 months	(46)
Fair Value, 12 months or more	0
Unrealized Loss, 12 months or more	0
Fair Value, Total	7,946
Unrealized Loss, Total	(46)
Municipal securities
Debt Securities, Available-for-sale [Abstract]
Fair Value, Less than 12 months	11,414	3,184
Unrealized Loss, Less than 12 months	(160)	(20)
Fair Value, 12 months or more	0	0
Unrealized Loss, 12 months or more	0	0
Fair Value, Total	11,414	3,184
Unrealized Loss, Total	(160)	(20)
U.S. Treasury securities
Debt Securities, Available-for-sale [Abstract]
Fair Value, Less than 12 months	14,908
Unrealized Loss, Less than 12 months	(6)
Fair Value, 12 months or more	0
Unrealized Loss, 12 months or more	0
Fair Value, Total	14,908
Unrealized Loss, Total	(6)
Corporate securities
Debt Securities, Available-for-sale [Abstract]
Fair Value, Less than 12 months	4,119	499
Unrealized Loss, Less than 12 months	(25)	(1)
Fair Value, 12 months or more	0	0
Unrealized Loss, 12 months or more	0	0
Fair Value, Total	4,119	499
Unrealized Loss, Total	$ (25)	$ (1)

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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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