Employee Benefit Plans (Amounts Recognized In Consolidated Balance Sheets) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Amounts recognized in consolidated balance sheet:
Long-term pension and benefit cost	$ 77,551	$ 75,155
Accumulated other comprehensive loss:
Accumulated Other Comprehensive Income (Loss), Net of Tax	(96,350)	(81,540)
Pension Plan [Member]
Amounts recognized in consolidated balance sheet:
Current accrued benefit cost	0	0
Long-term pension and benefit cost	66,849	63,396
Net amount recognized in consolidated balance sheet	66,849	63,396
Accumulated other comprehensive loss:
Net actuarial loss	(65,889)	(63,257)
Prior service credit	3,610	0
Accumulated Other Comprehensive Income (Loss), Net of Tax	(62,279)	(63,257)	$ (36,184)	$ (52,239)
Amount of Liabilities and Accumulated Other Comprehensive Loss Recognized in Consolidated Balance Sheet	4,570	139
Other Postretirement Benefits [Member]
Amounts recognized in consolidated balance sheet:
Current accrued benefit cost	612	687
Long-term pension and benefit cost	10,702	11,759
Net amount recognized in consolidated balance sheet	11,314	12,446
Accumulated other comprehensive loss:
Net actuarial loss	(7,280)	(8,744)
Prior service credit	3,335	7,048
Accumulated Other Comprehensive Income (Loss), Net of Tax	(3,945)	(1,696)	$ 3,053	$ 3,055
Amount of Liabilities and Accumulated Other Comprehensive Loss Recognized in Consolidated Balance Sheet	$ 7,369	$ 10,750