Derivative Financial Instruments - Impact of Derivatives on Consolidated Balance Sheet (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Derivatives, Fair Value [Line Items]
Total net derivatives	$ 66,000	$ 27,000
Interest rate swaps
Derivatives, Fair Value [Line Items]
Derivative instruments	772	2,090
Derivative Liabilities	(359)	(2,032)
Total net derivatives	413	58
Interest rate swaps | Trading
Derivatives, Fair Value [Line Items]
Derivative instruments	0	90
Derivative Liabilities	(111)	0
Total net derivatives	(111)	90
Interest rate swaps | Cash Flow | Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative instruments	772	0
Derivative Liabilities	0	(2,032)
Total net derivatives	772	(2,032)
Interest rate swaps | Fair Value | Designated as Hedging Instrument
Derivatives, Fair Value [Line Items]
Derivative instruments	0	2,000
Derivative Liabilities	(248)	0
Total net derivatives	$ (248)	$ 2,000