Defined Benefit Pension Plans (Defined Benefit Plans) (Details) - Pension Plan - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 320	$ 316
Interest cost	4,141	5,584
Expected return on assets	(7,018)	(7,471)
Amortization of actuarial loss	2,620	2,722
Net periodic cost	$ 63	$ 1,151