Derivatives and Hedging Activities Non-Designated Hedges (Details) - Not Designated as Hedging Instrument	Jun. 30, 2019 USD ($) derivative_contract	Dec. 31, 2018 USD ($) derivative_contract
Interest rate swaps
Derivative [Line Items]
Notional amount	$ 1,400,000,000	$ 1,300,000,000
Foreign exchange contracts
Derivative [Line Items]
Notional amount	0	100,000
Risk participation agreements
Derivative [Line Items]
Notional amount	$ 59,400,000	$ 59,800,000
Number of contracts | derivative_contract	7	7
Other Contract
Derivative [Line Items]
Notional amount	$ 20,600,000	$ 20,700,000
Number of contracts | derivative_contract	4	4