New Accounting Standards New Accounting Standards (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
AOCI Attributable to Parent [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Reclassification of excess income tax benefits	$ (1,742)	$ 0
Restatement Adjustment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit)		$ 2,000