New Accounting Standards - Narrative (Details) - Accounting Standards Update 2017-07 - USD ($) $ in Thousands	1 Months Ended	2 Months Ended	8 Months Ended
	Sep. 30, 2017	Aug. 31, 2017	Aug. 31, 2017
Sales General and Administrative Expense
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Interest cost	$ (397)	$ (806)	$ (3,227)
Net periodic pension and postretirement benefit	$ (692)	(1,213)	(4,854)
Interest Expense
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Interest cost		806	3,227
Other Income Net
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net periodic pension and postretirement benefit		$ 1,213	$ 4,854