Accumulated Other Comprehensive Income (Loss) - Reclassifications Out of Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2020	Mar. 31, 2019
Amortization of pension and postretirement benefits items:
Prior service benefit/cost	[1]		$ (25)
Actuarial loss (1)	[1]		9
Total before tax			(16)
Income tax			4
Amount reclassified out of accumulated other comprehensive loss		$ 1	$ (12)

[1] These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost in Note 3 “Employee Benefit Plans”