Derivative Financial Instruments - Effect of Cash Flow Derivatives on the Balance Sheet and Income Statement, Before Tax (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Interest Rate Swap Contracts [Abstract]
Gain (Loss) Reclassified from AOCI into Income	$ 2,507	$ (916)	$ (1,322)
Interest Rate Swap [Member]
Interest Rate Swap Contracts [Abstract]
Amount of Gain (Loss) Recognized in OCI on Derivative	1,306	768	(1,163)
Interest Rate Swap [Member] | Interest Expense [Member]
Interest Rate Swap Contracts [Abstract]
Gain (Loss) Reclassified from AOCI into Income	1,065	(706)	(1,296)
Interest Rate Cap [Member]
Interest Rate Swap Contracts [Abstract]
Amount of Gain (Loss) Recognized in OCI on Derivative	18	(183)	(605)
Interest Rate Cap [Member] | Interest Expense [Member]
Interest Rate Swap Contracts [Abstract]
Gain (Loss) Reclassified from AOCI into Income	(439)	(210)	(27)
Currency Swap 1 [Member]
Interest Rate Swap Contracts [Abstract]
Amount of Gain (Loss) Recognized in OCI on Derivative	1,584	0	0
Currency Swap [Member] | Interest Expense [Member]
Interest Rate Swap Contracts [Abstract]
Gain (Loss) Reclassified from AOCI into Income	949	0	0
Currency Swap [Member] | Other Income (Expense) [Member]
Interest Rate Swap Contracts [Abstract]
Gain (Loss) Reclassified from AOCI into Income	932	0	0
Currency Swap 2 [Member]
Interest Rate Swap Contracts [Abstract]
Amount of Gain (Loss) Recognized in OCI on Derivative	$ 0	$ 0	$ 0