Fair-Value Measurements (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Derivative [Line Items]
Interest expense (income)	$ (4,417)	$ (4,288)
Interest Rate Current Swap [Member]
Derivative [Line Items]
Interest expense (income)	(300)	500
Interest Rate Swap Buyouts [Member]
Derivative [Line Items]
Interest expense (income)	$ 100	$ 200