Effect of Cash Flow Derivatives on the Balance Sheet and Income Statement, Before Tax (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Derivative Instruments Designated as Hedging Instruments [Abstract]
Gain (Loss) Reclassified from AOCI into Income	$ (175)	$ (148)	$ 2,198	$ (785)
Interest Rate Swap [Member]
Derivative Instruments Designated as Hedging Instruments [Abstract]
Amount of Gain (Loss) Recognized in OCI on Derivative	302	81	2,062	(255)
Interest Rate Swap [Member] | Interest Expense [Member]
Derivative Instruments Designated as Hedging Instruments [Abstract]
Gain (Loss) Reclassified from AOCI into Income	314	(92)	649	(637)
Interest Rate Cap [Member]
Derivative Instruments Designated as Hedging Instruments [Abstract]
Amount of Gain (Loss) Recognized in OCI on Derivative	(220)	(24)	149	(225)
Interest Rate Cap [Member] | Interest Expense [Member]
Derivative Instruments Designated as Hedging Instruments [Abstract]
Gain (Loss) Reclassified from AOCI into Income	(149)	(55)	(685)	(148)
Currency Swap 1 [Member]
Derivative Instruments Designated as Hedging Instruments [Abstract]
Amount of Gain (Loss) Recognized in OCI on Derivative	599	0	2,975	0
Currency Swap 2 [Member]
Derivative Instruments Designated as Hedging Instruments [Abstract]
Amount of Gain (Loss) Recognized in OCI on Derivative	0	0	0	0
Currency Swap [Member] | Interest Expense [Member]
Derivative Instruments Designated as Hedging Instruments [Abstract]
Gain (Loss) Reclassified from AOCI into Income	363	0	570	0
Currency Swap [Member] | Other Income (Expense) [Member]
Derivative Instruments Designated as Hedging Instruments [Abstract]
Gain (Loss) Reclassified from AOCI into Income	$ (733)	$ 0	$ 1,635	$ 0