Loans - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 7,167,016,000		$ 7,167,016,000		$ 6,857,194,000
Syndication facilities included in loans	403,000,000		403,000,000		367,000,000
Collateral of cash, cash equivalents or other financial instruments	6,600,000		6,600,000		6,300,000
Interest income on nonaccrual loans	0	$ 0	0	$ 0
Interest receivable	32,900,000		32,900,000		27,700,000
Reversal of interest receivable	200,000		400,000
International
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	87,600,000		87,600,000		99,200,000
Consumer loans and overdrafts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	503,432,000		503,432,000		604,460,000
Reversal of interest receivable		100,000
Real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	5,073,043,000		5,073,043,000		4,858,208,000
Real estate loans | Single-family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,285,857,000		1,285,857,000		1,102,845,000
Payments to acquire loans held-for-investment	6,200,000		7,100,000
Real estate loans | Indirect Consumer Loans Purchased
Accounts, Notes, Loans and Financing Receivable [Line Items]
Payments to acquire loans held-for-investment		130,000,000		254,000,000
Commercial loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	1,577,209,000		1,577,209,000		1,381,234,000
Commercial loans | Single-family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Payments to acquire loans held-for-investment		$ 0		0
Commercial loans | Indirect Consumer Loans Purchased
Accounts, Notes, Loans and Financing Receivable [Line Items]
Payments to acquire loans held-for-investment	0		0
Indirect Consumer Loans Purchased | Consumer loans and overdrafts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	312,300,000		312,300,000		433,300,000
Under Non-Accrual Status
Accounts, Notes, Loans and Financing Receivable [Line Items]
Reversal of interest receivable				300,000
Under Non-Accrual Status | Consumer loans and overdrafts
Accounts, Notes, Loans and Financing Receivable [Line Items]
Reversal of interest receivable				200,000
Under Non-Accrual Status | Real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Reversal of interest receivable				$ 100,000
Pledged as Collateral
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans	$ 1,900,000,000		$ 1,900,000,000		$ 1,200,000,000