Pension and Other Post-Retirement Benefit Plans (Net Periodic Benefit Costs) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension Plans [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 0	$ 0	$ 0
Interest cost	31,299	29,135	33,585
Expected return on plan assets	(37,907)	(42,093)	(42,080)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	0	0	12,923
Amortization of prior service cost	0	0	0
Amortization of net (gain) loss	15,528	3,547	7,778
Net periodic benefit cost (income)	8,920	(9,411)	12,206
Pension Plans [Member] | Continuing Operations [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement			(5,300)
Pension Plans [Member] | Discontinued Operations [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement			(7,600)
Post-Retirement Healthcare Plans [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	107	123	158
Interest cost	148	127	142
Expected return on plan assets	0	0	0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	0	0	0
Amortization of prior service cost	0	0	(51)
Amortization of net (gain) loss	172	219	283
Net periodic benefit cost (income)	$ 427	$ 469	$ 532