Pension and Other Postretirement Benefits (Details 9) (Defined benefit pension plans [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 453,578	$ 387,553	$ 340,370
Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	181,045	141,669
Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	270,754	244,350
Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,779	1,534
Cash and short-term investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	18,885	14,633
Cash and short-term investments [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	18,885	14,633
Cash and short-term investments [Member] | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Cash and short-term investments [Member] | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Equity Securities, U.S. large-cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	131,749	95,145
Equity Securities, U.S. large-cap [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	61,257	43,388
Equity Securities, U.S. large-cap [Member] | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	70,492	51,757
Equity Securities, U.S. large-cap [Member] | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Equity Securities, U.S. mid-cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	47,276	41,090
Equity Securities, U.S. mid-cap [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	47,276	41,090
Equity Securities, U.S. mid-cap [Member] | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Equity Securities, U.S. mid-cap [Member] | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Equity Securities, U.S. small-cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	53,627	42,558
Equity Securities, U.S. small-cap [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	53,627	42,558
Equity Securities, U.S. small-cap [Member] | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Equity Securities, U.S. small-cap [Member] | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Equity Securities, International equities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	80,479	77,111
Equity Securities, International equities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Equity Securities, International equities [Member] | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	80,479	77,111
Equity Securities, International equities [Member] | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
U.S. bond funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	65,740	66,276
U.S. bond funds [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
U.S. bond funds [Member] | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	65,740	66,276
U.S. bond funds [Member] | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
International bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	37,357	29,032
International bonds [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
International bonds [Member] | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	37,357	29,032
International bonds [Member] | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Real estate securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	16,686	20,174
Real estate securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Real estate securities [Member] | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	16,686	20,174
Real estate securities [Member] | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Other [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	1,779	1,534
Other [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Other [Member] | Significant Other Observable Inputs (Level 2)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	0	0
Other [Member] | Significant Unobservable Inputs (Level 3)
Defined Benefit Plan Disclosure [Line Items]
Fair Value of Plan Assets	$ 1,779	$ 1,534