Pension and Other Post-Retirement Benefit Plans (Net Periodic Benefit Costs) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements and Curtailments	$ (12,900)
Continuing Operations [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements and Curtailments	(5,300)
Discontinued Operations [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements and Curtailments	(7,600)
Pension Plans [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	0	$ 0	$ 0	$ 0
Interest cost	8,396	8,968	25,946	26,904
Expected return on plan assets	(10,520)	(10,264)	(32,379)	(30,792)
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements and Curtailments	12,923	0	12,923	0
Amortization of prior service cost	0	0	0	0
Amortization of net loss	1,944	3,368	5,819	10,104
Net periodic benefit cost	12,743	2,072	12,309	6,216
Post-Retirement Healthcare Plans [Member]
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]
Service cost	39	31	117	93
Interest cost	36	42	108	126
Expected return on plan assets	0	0	0	0
Defined Benefit Plan, Recognized Net Gain (Loss) Due to Settlements and Curtailments	0	0	0	0
Amortization of prior service cost	(13)	(26)	(39)	(78)
Amortization of net loss	71	40	213	120
Net periodic benefit cost	$ 133	$ 87	$ 399	$ 261