Benefit Plans and Other Postretirement Benefits, Projected Benefit Payments (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014
Pension Plans
Defined Benefit Plan, Gross Projected Benefit Payments [Abstract]
2015	$ 74,237
2016	77,804
2017	77,126
2018	80,003
2019	82,472
2020-2024	423,835
Postretirement Benefit Plan
Defined Benefit Plan, Gross Projected Benefit Payments [Abstract]
2015	32,300
2016	32,991
2017	33,328
2018	34,146
2019	34,053
2020-2024	165,560
Expected Medicare Part D Subsidies [Abstract]
2015	2,532
2016	2,692
2017	2,863
2018	3,033
2019	3,192
2020-2024	18,053
Defined Benefit Plan, Net Projected Benefit Payments [Abstract]
2015	29,768
2016	30,299
2017	30,465
2018	31,113
2019	30,861
2020-2024	$ 147,507

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The amount of the benefits expected to be paid, net of the prescription drug subsidy receipts expected to be received in the five fiscal years thereafter (the aggregate net amount of benefits expected to be paid in years 6 through 10 after the date of the latest statement of financial position).