Acquisition of First Priority Financial Corp. (Fair Value Adjustments) (Details) - First Priority Financial Corp. [Member]	Jul. 31, 2018 USD ($)
Business Acquisition [Line Items]
Gross amortized cost basis at July 31, 2018	$ 521,644,000
Market rate adjustment	(3,023,000)
Credit fair value adjustment on pools of homogeneous loans	(6,742,000)
Credit fair value adjustment on impaired loans	(256,000)
Fair value of purchased loans at July 31, 2018	$ 511,623,000

Purchased loans credit fair value adjustment on impaired loans

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Purchased loans, credit fair value adjustment on pools of homogeneous loans

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Purchased loans market rate adjustment

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Fair value of acquired receivable from business combination, excluding certain loans and debt securities acquired in transfer.

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The amount of financial assets (as defined) recognized as of the acquisition date.

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