Income Taxes (Operating Loss Carryforwards) (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Operating Loss Carryforwards
Deferred tax asset valuation allowance	$ 23,696	$ 29,719
Operating loss carryforwards, valuation allowance	481
State and local
Operating Loss Carryforwards
Deferred tax asset valuation allowance	1,708
Operating loss carryforward	$ 1,708	$ 1,378
State and local | Maximum
Operating Loss Carryforwards
Operating loss carryforwards, expiration date	Dec. 31, 2037
Foreign tax authority | Secretariat of the Federal Revenue Bureau of Brazil
Operating Loss Carryforwards
Operating loss carryforward	$ 1,363