Derivatives, Hedging Activities, and Other Financial Instruments - Narrative (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Derivative [Line Items]
Collateral already posted, fair value	$ 8,800,000		$ 8,800,000		$ 4,100,000
Derivative liability	7,300,000		7,300,000		$ 1,800,000
Interest Rate Swap
Derivative [Line Items]
Income (expense) in fair value adjustments	$ (141,000)	$ 0	$ (195,000)	$ 2,000