Equity and EPS - Reclassification out of Accumulated Other Comprehensive Income (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	$ (111)
Pension Plan Items
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service cost	(155)
Reclassification from AOCI, Current Period, Tax	40
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(115)
Post Employment Benefit Items: Amortization of prior service cost
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service cost	(339)
Post Employment Benefit Items: Recognized net actuarial loss
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service cost	(184)
Other
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Amortization of prior service cost	7
Reclassification from AOCI, Current Period, Tax	(3)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	$ 4