Pension and Other Postretirement Benefits (Summary of Fair Value of Plan Assets by Level) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	$ 172,976	$ 162,182
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	29,158	30,100
Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	142,741	130,886
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	1,077	1,196	1,336
Exchange traded funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	28,287	29,831
Exchange traded funds [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	28,287	29,831
Exchange traded funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	0	0
Exchange traded funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	0	0
Cash and cash equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	871	269
Cash and cash equivalents [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	871	269
Cash and cash equivalents [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	0	0
Cash and cash equivalents [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	0	0
Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	94,928	79,800
Fixed Income Funds [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	0	0
Fixed Income Funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	94,928	79,800
Fixed Income Funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	0	0
Equity Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	47,813	51,086
Equity Funds [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	0	0
Equity Funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	47,813	51,086
Equity Funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	0	0
Insurance Company Investment Contract [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	1,077	1,196
Insurance Company Investment Contract [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	0	0
Insurance Company Investment Contract [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	0	0
Insurance Company Investment Contract [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of financial assets of the Plan	$ 1,077	$ 1,196