Savings Plans, Pension Plans and Other Postretirement Employee Benefits (Fair Value Measurements) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Fair Value of Plan Assets	$ 337,059		$ 350,588
Cash and Cash Equivalents [Member]
Cash and Equivalents	6,586		9,673
Equity Securities [Member]
U.S. Large Cap			32,304	[1]
U.S. Small Mid Cap	1,136	[2]	19,053	[2]
International Companies	13,782		34,773
Mutual Funds [Member]
Mutual Funds	226,710	[3]	185,505	[4]
Percent Invested in High-Quality Intermediate and Long-Term Investment Grade Securities	72.00%		50.00%
Percent Invested in Diversified Portfolio of Fixed-Income Instruments of Varying Maturities	22.00%		50.00%
Defined Benefit Plan, Fair Vale Measurements, Mutual Funds, Percent Invested in US Small/Mid Cap Equities that Track Russell 2500 Growth Index	6.00%
Investments [Member]
U.S. Large Cap			30,005	[5]
Developed Markets	29,879	[6]	17,401	[7]
Emerging Markets	28,961	[8]	41,300	[8]
Hedge Funds [Member]
Hedge Funds			10,579	[9]
Percent Invested in Long/Short and Event-Driven Equity			37.00%
Percent Invested in Long and Short Credit			24.00%
Percent in Relative Value			11.00%
Percent Invested in Distressed Debt			10.00%
Defined Benefit Plan, Fair Value Investments, Hedge Funds, Percent Invested in Convertible Bond Hedging			6.00%
Percent in Other Investments			13.00%
Level 1 [Member]
Cash and Equivalents	31,012		57,837
Fair Value of Plan Assets	248,214		281,308
Level 1 [Member] | Cash and Cash Equivalents [Member]
Cash and Equivalents	6,586		9,673
Level 1 [Member] | Equity Securities [Member]
U.S. Large Cap			32,304	[1]
U.S. Small Mid Cap	1,136	[2]	19,053	[2]
International Companies	13,782		34,773
Level 1 [Member] | Mutual Funds [Member]
Mutual Funds	226,710	[3]	185,505	[4]
Level 1 [Member] | Investments [Member]
U.S. Large Cap			0	[5]
Developed Markets	0	[6]	0	[7]
Emerging Markets	0	[8]	0	[8]
Level 1 [Member] | Hedge Funds [Member]
Hedge Funds			0	[9]
Level 2 [Member]
Fair Value of Plan Assets	88,845		58,701
Level 2 [Member] | Cash and Cash Equivalents [Member]
Cash and Equivalents	0		0
Level 2 [Member] | Equity Securities [Member]
U.S. Large Cap			0	[1]
U.S. Small Mid Cap	0	[2]	0	[2]
International Companies	0		0
Level 2 [Member] | Mutual Funds [Member]
Mutual Funds		[3]	0	[4]
Level 2 [Member] | Investments [Member]
U.S. Large Cap			30,005	[5]
Developed Markets	29,879	[6]	17,401	[7]
Emerging Markets	28,961	[8]	41,300	[8]
Level 2 [Member] | Hedge Funds [Member]
Hedge Funds			0	[9]
Level 3 [Member]
Fair Value of Plan Assets	0		10,579
Level 3 [Member] | Cash and Cash Equivalents [Member]
Cash and Equivalents	0		0
Level 3 [Member] | Equity Securities [Member]
U.S. Large Cap			0	[1]
U.S. Small Mid Cap	0	[2]	0	[2]
International Companies	0		0
Level 3 [Member] | Mutual Funds [Member]
Mutual Funds	0	[3]	0	[4]
Level 3 [Member] | Investments [Member]
U.S. Large Cap			0	[5]
Developed Markets	0	[6]	0	[7]
Emerging Markets	0	[8]	0	[8]
Level 3 [Member] | Hedge Funds [Member]
Hedge Funds			$ 10,579	[9]

[1] These are managed investments in US large cap equities that track the Russell 1000 Value index.

[2] These are managed investments in US small/mid cap equities that track the Russell 2500 Growth index.

[3] The mutual funds were 72% invested in high-quality intermediate and long-term investment grade securities, 22% invested in a diversified portfolio of fixed-income instruments of varying maturities, which may be represented by forwards or derivatives such as options, futures contracts or swap agreements and debt securities, and 6% invested in US small/mid cap equities that track the Russell 2500 Growth index.

[4] The mutual funds were 50% invested in high-quality intermediate and long-term investment grade securities and 50% invested in a diversified portfolio of fixed-income instruments of varying maturities, which may be represented by forwards or derivatives such as options, futures contracts or swap agreements and debt securities.

[5] These collective investments are invested in US large cap equities that track the S&P 500.

[6] These collective investments are invested in equity funds of developed markets outside of the US & Canada, that track the MSCI EAFE Value or MSCI EAFE Growth index.

[7] These collective investments are invested in equity funds of developed markets outside of the US & Canada, that track the MSCI EAFE index.

[8] These collective investments are invested in equity funds of emerging markets outside of the US & Canada, that track the MSCI Emerging Markets index.

[9] The hedge funds are 37% invested in long/short and event-driven equity, 24% invested in long and short credit, 11% in relative value, 10% invested in distressed debt, 6% invested in convertible bond hedging, with the remaining 13% in other investments.