Employee Benefit Plans (Schedule of Amounts Recognized in Accumulated Other Comprehensive Income) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Pension Plans, Defined Benefit [Member]
Amounts In AOCI [Line Items]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), before Tax	$ 41,238	$ 22,507
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Prior Service Costs (Credit) Arising During Period, Net of Tax	1,496	1,981
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	42,734	24,488
Other Postretirement Benefit Plans, Defined Benefit [Member]
Amounts In AOCI [Line Items]
Pension and Other Postretirement Benefit Plans, Accumulated Other Comprehensive Income (Loss), Net Gains (Losses), before Tax	32,949	8,655
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Prior Service Costs (Credit) Arising During Period, Net of Tax	0	0
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax	$ 32,949	$ 8,655