Basis of Presentation (Narratives) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Basis of Presentation [Abstract]
(Income) expense from deferred compensation plan liability	$ (404)	$ 2,469
(Loss) income from deferred compensation plan assets	$ (404)	$ 2,469