Retirement Plans (Fair Value of Plan Assets by Fair Value Level) (Details) (Pension Plan [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 98,187		$ 82,521		$ 86,741
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	81,278		65,865
Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16,909		16,656
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
Total Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	98,187		82,521
Cash [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,708		1,773
Cash [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
Cash [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
Cash [Member] | Total Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,708		1,773
U.S. large- and mid-cap stocks [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	44,158	[1]	35,503	[1]
U.S. large- and mid-cap stocks [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	[1]	0	[1]
U.S. large- and mid-cap stocks [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	[1]	0	[1]
U.S. large- and mid-cap stocks [Member] | Total Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	44,158	[1]	35,503
U.S. small-cap mutual funds [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,076		3,303
U.S. small-cap mutual funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
U.S. small-cap mutual funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
U.S. small-cap mutual funds [Member] | Total Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,076		3,303
International large-cap mutual funds [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9,009		10,659
International large-cap mutual funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
International large-cap mutual funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
International large-cap mutual funds [Member] | Total Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	9,009		10,659
Emerging markets mutual funds [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,291		3,954
Emerging markets mutual funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
Emerging markets mutual funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
Emerging markets mutual funds [Member] | Total Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,291		3,954
Common Stock [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,005		4,726
Common Stock [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
Common Stock [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
Common Stock [Member] | Total Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,005		4,726
U.S. Treasury and government sponsored agency bonds and notes [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4,876		5,717
U.S. Treasury and government sponsored agency bonds and notes [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,056		2,053
U.S. Treasury and government sponsored agency bonds and notes [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
U.S. Treasury and government sponsored agency bonds and notes [Member] | Total Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,932		7,770
Corporate bonds [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	[2]	0	[2]
Corporate bonds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15,853	[2]	14,603	[2]
Corporate bonds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
Corporate bonds [Member] | Total Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15,853	[2]	14,603
Mutual funds [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,005	[3]
Mutual funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	[3]
Mutual funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	[3]
Mutual funds [Member] | Total Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,005	[3]
Other debt securities [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	150		230
Other debt securities [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
Other debt securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0		0
Other debt securities [Member] | Total Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 150		$ 230

[1] Comprised of common stocks traded on U.S. Exchanges whose issuers had market capitalizations exceeding $3 billion

[2] Comprised of investment grade bonds of U.S. issuers from diverse industries.

[3] Comprised primarily of fixed-income bonds issued by the U.S. Treasury and government sponsored agencies and bonds of U.S. and foreign issuers from diverse industries.