Summary of Significant Accounting Policies - Revenue from Contracts with Customers (Details) $ in Thousands	3 Months Ended
Mar. 31, 2019 USD ($) contract	Mar. 31, 2018 USD ($) contract
Summary of Significant Accounting Policies
Number of active contracts \| contract	816,000	791,000
Transferred at Point in Time
Summary of Significant Accounting Policies
Revenue from contract with customers	$ 24,100	$ 33,800
Transferred over Time
Summary of Significant Accounting Policies
Revenue from contract with customers	5,000	4,800
Interchange and debit card transaction fees
Summary of Significant Accounting Policies
Revenue from contract with customers	2,600	7,600
Interchange and debit card transaction fees \| Before 606
Summary of Significant Accounting Policies
Transaction fees	5,500	10,600
Network costs	2,900	3,000
Trust and investment services income
Summary of Significant Accounting Policies
Revenue from contract with customers	7,269	7,514
Deposit account services
Summary of Significant Accounting Policies
Revenue from contract with customers	$ 18,100	$ 25,800

The number of active contracts to which services are provided.

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The aggregate cost of goods produced and sold and services rendered during the reporting period.

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Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

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Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

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