Pension and Other Post-Retirement Benefit Plans (Unrecognized Net Periodic Benefit Expense) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	$ 12,923	$ 0	$ 0
Unrecognized prior service cost	0	0
Unrecognized net actuarial loss	88,689	112,506
Accumulated other comprehensive loss	88,689	112,506
Post-Retirement Healthcare Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	0	(1,997)	$ 0
Unrecognized prior service cost	0	(51)
Unrecognized net actuarial loss	1,547	1,893
Accumulated other comprehensive loss	1,547	$ 1,842
Continuing Operations [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	(5,300)
Discontinued Operations [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement	$ (7,600)