Income Tax (Reconciliation of unrecognized tax benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation Of Unrecognized Tax Benefits Excluding Amounts Pertaining To Examined Tax Returns Roll Forward
Balance at beginning of year	$ 2,040	$ 2,175	$ 2,560
Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions	97	229	175
Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities	0	999	560
Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations	877	1,363	0
Balance at end of year	$ 1,260	$ 2,040	$ 2,175