Derivative Financial Instruments Schedule of Fair Value Hedging Instruments, Statements of Financial Performance and Financial Position, Location (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Derivative [Line Items]
Derivative Asset, Fair Value, Amount Offset Against Collateral	$ 6,240	$ 2,495
Derivative Asset	181,804	38,847
Derivative Liability, Fair Value, Amount Offset Against Collateral	6,240	2,495
Derivative Liability	1,314	36,515
Derivative Asset, Fair Value, Amount Not Offset Against Collateral	201	755
Derivative Asset, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election	57	1,742
Derivative Liability, Fair Value, Amount Not Offset Against Collateral	104	0
Derivative Liability, Fair Value, Offset Against Collateral, Net of Not Subject to Master Netting Arrangement, Policy Election	34	71
Designated as Hedging Instrument [Member]
Derivative [Line Items]
Derivative Liability, Fair Value, Gross Liability	8,816	2,566
Derivative Asset, Fair Value, Gross Asset	19,683	9,928
Derivative Asset, Fair Value, Amount Offset Against Collateral	19,539	7,431
Derivative Asset	144	2,497
Derivative Liability, Fair Value, Amount Offset Against Collateral	8,746	2,495
Derivative Liability	$ 70	$ 71