Retirement Plans (Fair Value of Plan Assets by Fair Value Level) (Details) - Pension Plan [Member] - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Net Periodic Benefit Cost		$ 1,575		$ (45)	$ 1,725
Fair value of plan assets		126,930		130,775	$ 128,829
Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		126,930		130,775
Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		120,561		121,918
Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		6,369		8,857
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0		0
Cash [Member] | Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		354		2,594
Cash [Member] | Quoted Prices In Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		354		2,594
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
U.S. large- and mid-cap stocks [Member] | Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		55,709	[1]	56,718
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	[1]	55,709		56,718
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	[1]	0		0
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	[1]	0		0
U.S. small-cap mutual funds [Member] | Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		4,749		5,409
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		4,749		5,409
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
International large-cap mutual funds [Member] | Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		14,124		14,805
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		14,124		14,805
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
Emerging markets mutual funds [Member] | Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		4,886		6,004
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		4,886		6,004
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
Common Stock [Member] | Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		7,219		6,455
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		7,219		6,455
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
U.S. Treasury and government sponsored agency bonds and notes [Member] | Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		2,815		3,041
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		0		998
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		2,815		2,043
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
Corporate bonds [Member] | Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		3,554	[2]	6,814
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	[2]	0		0
Corporate bonds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[2]	3,554		6,814
Corporate bonds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0		0
Mutual funds [Member] | Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[3]	33,424		28,795
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	[3]	33,424		28,795
Mutual funds [Member] | Significant Other Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[3]	0		0
Mutual funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	[3]	0		0
Other debt securities [Member] | Fair Value [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		96		140
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		96		140
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

[1] Comprised of common stocks and mutual funds 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.