Subsequent Events (Detail) - Subsequent Event - Century Merger Agreement $ / shares in Units, $ in Millions	Apr. 07, 2021 USD ($) bank $ / shares
Subsequent Event [Line Items]
Cash payment	$ 641.9
Assets acquired	6,400.0
Deposits acquired	$ 5,400.0
Number of full-service branches acquired \| bank	27
Common Class A
Subsequent Event [Line Items]
Share price (in dollars per share) \| $ / shares	$ 115.28
Common Class B
Subsequent Event [Line Items]
Share price (in dollars per share) \| $ / shares	$ 115.28

Business Combination, Number of Banks Acquired

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- Definition

Price of a single share of a number of saleable stocks paid or offered to be paid in a business combination.

+ References

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- Definition

Amount of assets acquired at the acquisition date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 20
-Section 50
-Paragraph 1
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- Definition

Amount of liabilities assumed at the acquisition date.

+ References

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- Definition

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
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-Name Accounting Standards Codification
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- Definition

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

+ References

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