Subsequent Events (Details) - Merger Agreement - Northwest Bancshares - Subsequent Event $ in Millions	Oct. 18, 2019 USD ($) shares
Subsequent Event [Line Items]
Right to receive number of shares \| shares	2.4
Total consideration \| $	$ 346

Amount of consideration transferred, consisting of acquisition-date fair value of assets transferred by the acquirer, liabilities incurred by the acquirer, and equity interest issued by the acquirer.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-Section 30
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