International Retirement Plan (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Non-Contributory Defined Benefit Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Net present value of annuity	$ 3,207	$ 2,760
International Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Unrecognized net gain (loss)	555	(1,437)
Actuarial amortization	244	128
Tax (benefit) provision	247	(407)
Adjustment to AOCI	$ (552)	$ 902