Derivative and Hedging Activities - Fair Value of Derivatives (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Derivatives Not Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	$ 14,405	$ 6,304
Liability Derivatives	14,766	6,315
Derivatives Not Designated as Hedging Instrument [Member] | Other Assets [Member] | Interest Rate Products [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	14,154	6,303
Derivatives Not Designated as Hedging Instrument [Member] | Other Assets [Member] | Credit Risk Contract [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	251	1
Derivatives Not Designated as Hedging Instrument [Member] | Other Liabilities [Member] | Interest Rate Products [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	14,766	6,315
Derivatives Not Designated as Hedging Instrument [Member] | Other Liabilities [Member] | Credit Risk Contract [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	0	0
Designated as Hedging Instrument [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	1,229	915
Liability Derivatives	0	0
Designated as Hedging Instrument [Member] | Other Assets [Member] | Interest Rate Products [Member]
Derivatives, Fair Value [Line Items]
Asset Derivatives	1,229	915
Designated as Hedging Instrument [Member] | Other Liabilities [Member] | Interest Rate Products [Member]
Derivatives, Fair Value [Line Items]
Liability Derivatives	$ 0	$ 0