New Accounting Standards - Narrative (Details) - Accounting Standards Update 2017-07 - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2017
Sales General and Administrative Expense
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Interest cost	$ (1,211)	$ (2,421)
Net periodic pension and postretirement benefit	(1,821)	(3,641)
Interest Expense
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Interest cost	1,211	2,421
Other Income Net
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net periodic pension and postretirement benefit	$ 1,821	$ 3,641