Business Combination - Fair Value of Other Intangible Assets Acquired and Useful Lives (Details) - Boston Private $ in Millions	Jul. 01, 2021 USD ($)
Other intangible assets:
Estimated Fair Value	$ 104
Customer relationships
Other intangible assets:
Estimated Fair Value	$ 85
Weighted Average Estimated Useful Life - in Years	20 years
Other
Other intangible assets:
Estimated Fair Value	$ 19
Weighted Average Estimated Useful Life - in Years	6 years