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Segment Reporting (Narrative) (Details) $ in Thousands	9 Months Ended
Segment Reporting (Narrative) (Details) $ in Thousands	Sep. 30, 2022 USD ($) Segment	Jan. 31, 2022 USD ($)	Jan. 01, 2022 USD ($)	Dec. 31, 2021 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments \| Segment	3
Deposits	$ 54,008,887			$ 29,847,029
Goodwill	$ 2,513,771			$ 538,373	$ 538,373	$ 538,373
Sterling
Segment Reporting Information [Line Items]
Goodwill		$ 1,939,432	$ 1,900,000
Commercial Banking \| Sterling
Segment Reporting Information [Line Items]
Goodwill		1,700,000
Consumer Banking
Segment Reporting Information [Line Items]
Deposits			125,400
Consumer Banking \| Assets Under Administration
Segment Reporting Information [Line Items]
Off-balance sheet assets			4,300,000
Consumer Banking \| Sterling
Segment Reporting Information [Line Items]
Goodwill		$ 200
HSA Bank \| Bend
Segment Reporting Information [Line Items]
Goodwill			$ 36,000