Accumulated Other Comprehensive Income (Loss) - Reclassifications Out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Amortization of pension and postretirement benefits items:
Prior service benefit/cost		$ (10)
Actuarial loss	$ (60)	(1,728)
Settlement expense	526	19,900
Total before tax	466	18,162
Income tax	(133)	(4,994)
Amount reclassified out of accumulated other comprehensive income (loss)	$ 333	$ 13,168